add memory.fill/memory.copy intrinsics

Cargo.lock

@@ -13,9 +13,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.44"
+version = "1.0.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61604a8f862e1d5c3229fdd78f8b02c68dcf73a4c4b05fd636d12240aaa242c1"
+checksum = "159bb86af3a200e19a068f4224eae4c8bb2d0fa054c7e5d1cacd5cef95e684cd"
 
 [[package]]
 name = "ariadne"
@@ -83,9 +83,9 @@ dependencies = [
 
 [[package]]
 name = "getrandom"
-version = "0.2.3"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fcd999463524c52659517fe2cea98493cfe485d10565e7b0fb07dbba7ad2753"
+checksum = "d39cd93900197114fa1fcb7ae84ca742095eed9442088988ae74fa744e930e77"
 dependencies = [
  "cfg-if",
  "libc",
@@ -106,9 +106,9 @@ checksum = "884e2677b40cc8c339eaefcb701c32ef1fd2493d71118dc0ca4b6a736c93bd67"
 
 [[package]]
 name = "libc"
-version = "0.2.105"
+version = "0.2.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "869d572136620d55835903746bcb5cdc54cb2851fd0aeec53220b4bb65ef3013"
+checksum = "1bf2e165bb3457c8e098ea76f3e3bc9db55f87aa90d52d0e6be741470916aaa4"
 
 [[package]]
 name = "pico-args"

README.md

@@ -56,6 +56,14 @@ Then run it on [MicroW8](https://exoticorn.github.io/microw8/v0.1pre2)
 */
 ```
 
+### Include
+
+Other sourcefiles can be included with the `include` top level statement:
+
+```
+include "platform_imports.cwa"
+```
+
 ### Types
 
 There are four types in WebAssembly and therefore CurlyWas:
@@ -81,16 +89,25 @@ For floating point numbers, only the most basic decimal format is currently impl
 0.464, 3.141, -10.0
 ```
 
-String literals exist in a very basic form. No escape character implemented yet.
+String literals are used for include paths, import names and as literal strings in the data section. The following escapes are supported:
+| Escape | Result | Comment                            |
+| `\"`   | `"`    |                                    |
+| `\'`   | `'`    |                                    |
+| `\t`   | 8      |                                    |
+| `\n`   | 10     |                                    |
+| `\r`   | 13     |                                    |
+| `\N`   | 0x0N   | (Can't be followed by a hex digit) |
+| `\NN`  | 0xNN   |                                    |
 
 ```
 "env.memory", "Hello World!"
 
-this does not work, yet:
-
 "one line\nsecond line", "They said: \"Enough!\""
 ```
 
+Character literals are enclosed in single quotes `'` and support the same escapes as strings. They can contain up to 4 characters and evaluate to the
+little-endian representation of these characters. For examples: `'A'` evaluates to `0x41`, `'hi'` evaluates to 0x6968, and `'Crly'` to 0x7a6c7243.
+
 ### Imports
 
 WebAssembly imports are specified with a module and a name. In CurlyWas you give them inside a single string literal, seperated by a dot. So a module `env` and name `printString` would be written `"env.printString"`.
@@ -138,6 +155,18 @@ can use it. However, exporting global variable is not yet supported in CurlyWas.
 
 The type is optional, if missing it is inferred from the init value.
 
+### Constants
+
+Constants can be declared in the global scope:
+
+```
+const name[: type] = value;
+```
+
+`value` has to be an expression evaluating to a constant value. It may reference other constants.
+
+The type is optional, but if given has to match the type of `value`.
+
 ### Functions
 
 Functions look like this:
@@ -275,6 +304,9 @@ So for example this block evaluates to 12:
 
 Blocks are used as function bodies and in flow control (`if`, `block`, `loop`), but can also used at any point inside an expression.
 
+Variable re-assignments of the form `name = name <op> expression` can be shortened to `name <op>= expression`, for example `x += 1` to increment `x` by one. This works for all arithmetic, bit and shift operators.
+The same is allowed for `name := name <op> expression`, ie. `x +:= 1` increments `x` and returns the new value.
+
 #### Flow control
 
 `if condition_expression { if_true_block } [else {if_false_block}]` executes the `if_true_block` if the condition evaluates to a non-zero integer and
@@ -284,6 +316,17 @@ the `if_false_block` otherwise (if it exists). It can also be used as an express
 let a = if 0 { 2 } else { 3 }; // assigns 3 to a
 ```
 
+If the `if_false_block` contains exactly one `if` expression or statement you may omit the curly braces, writing `else if` chains like:
+```
+if x == 0 {
+    doOneThing()
+} else if x == 1 {
+    doThatOtherThing()
+} else {
+    keepWaiting()
+}
+```
+
 `block name { ... }` opens a named block scope. A branch statement can be used to jump to the end of the block. Currently, `block` can only be used
 as a statement, returning a value from the block is not yet supported.
 
@@ -296,15 +339,65 @@ non-zero integer.
 
 #### Memory load/store
 
-To read from memory you specify a memory location as `base?offset` or `base!offset`. `?` reads a byte and `!` reads a 32bit word.
+To read from memory you specify a memory location as `base?offset`, `base!offset` or `base$offset`. `?` reads a byte, `!` reads a 32bit word
+and `$` reads a 32bit float.
 
 `base` can be any expression that evaluates to an `i32` while `offset` has to be a constant `i32` value. The effective memory address is the sum of both.
 
-Writing to memory looks just like an assignment to a memory location: `base?offset = expressoin` and `base!offset = expression`.
+Writing to memory looks just like an assignment to a memory location: `base?offset = expression`, `base!offset = expression` and `base$offset = expression`.
 
 When reading/writing 32bit words you need to make sure the address is 4-byte aligned.
 
-These compile to `i32.load8_u`, `i32.load`, `i32.store8` and `i32.store`. Other WASM load/store instructions will be implemented as intrinsics, but aren't yet. 
+These compile to `i32.load8_u`, `i32.load`, `f32.load`, `i32.store8`, `i32.store` and `f32.store`.
+
+In addition, all wasm memory instructions are available as intrinsics:
+
+```
+<load-ins>(<base-address>[, <offset>, [<align>]])
+
+offset defaults to 0, align to the natural alignment: 0 for 8bit loads, 1 for 16bit, 2 for 32 bit and 3 for 64bit.
+```
+
+with `<load-ins>` being one of `i32.load`, `i32.load8_u`, `i32.load8_s`, `i32.load16_u`, `i32.load16_s`,
+`i64.load`, `i64.load8_u`, `i64.load8_s`, `i64.load16_u`, `i64.load16_s`, `i32.load32_u`, `i32.load32_s`,
+`f32.load` and `f64.load`.
+
+```
+<store-ins>(<value>, <base-address>[, <offset>, [<align>]])
+
+offset and align defaults are the same as the load intrinsics.
+```
+with `<store-ins>` being one of `i32.store`, `i32.store8`, `i32.store16`, `i64.store`, `i64.store8`,
+`i64.store16`, `i64.store32`, `f32.store` and `f64.store`.
+
+#### Data
+
+Data sections are written in `data` blocks:
+
+```
+data <address> {
+    ...
+}
+```
+
+The content of such a block is loaded at the given address at module start.
+
+Inside the data block you can include 8, 16, 32, 64, f32 or f64 values:
+
+```
+i8(1, 255) i16(655350) i32(0x12345678) i64(0x1234567890abcdefi64) f32(1.0, 3.141) f64(0.5f64)
+```
+
+Strings:
+```
+"First line" i8(13, 10) "Second line"
+```
+
+And binary files:
+
+```
+file("font.bin")
+```
 
 #### Advanced sequencing
 

examples/microw8/palette.cwa

@@ -1,29 +1,8 @@
-import "env.memory" memory(4);
+include "uw8.cwa"
 
-import "env.pow" fn pow(f32, f32) -> f32;
+const SWEETY = PALETTE + 192 * 4;
-import "env.sin" fn sin(f32) -> f32;
-import "env.cos" fn cos(f32) -> f32;
-import "env.atan2" fn atan2(f32, f32) -> f32;
-import "env.tan" fn tan(f32) -> f32;
-import "env.atan" fn atan(f32) -> f32;
-import "env.rectangle" fn rect(f32, f32, f32, f32, i32);
 
-//export fn tic(time: i32) {
+export fn upd() {
-//    let i: i32;
-//    loop pixels {
-//        let lazy x = (i % 320) as f32 - 160.5;
-//        let lazy y = (i / 320 - 120) as f32;
-//
-//        let lazy dist = 4000 as f32 / sqrt(x*x + y*y + 10 as f32);
-//        let lazy angle = atan2(x, y) * (64.0 / 3.141);
-//
-//        i?120 = ((((dist + time as f32 / 63 as f32) as i32 ^ angle as i32) #% 32 + 32) >> ((dist as i32 - i % 7 * 3) / 40)) + 192;
-//
-//        branch_if (i := i + 1) < 320*240: pixels;
-//    }
-//}
-
-export fn tic(time: i32) {
     let i: i32;
     loop colors {
         rect((i % 16 * 15) as f32, (i / 16 * 15) as f32, 15 as f32, 15 as f32, i);
@@ -43,7 +22,7 @@ start fn gen_palette() {
         let lazy a = max(llimit, min(ulimit, c)) * (scale + 0.05);
         let lazy b = scale * scale * 0.8;
         let inline v = (select(i < 11*16*3, max(0 as f32, min(a + b - a * b, 1 as f32)), scale) * 255 as f32) as i32;
-        (i%3 + i/3*4)?(120+320*240) = v;
+        (i%3 + i/3*4)?PALETTE = v;
         avg = (avg + c) * 0.5;
 
         branch_if i := i - 1: gradients;
@@ -56,15 +35,15 @@ start fn gen_palette() {
         let lazy first_step = index >= 32;
         let inline src1 = select(first_step, index % 32 / 2, index * 2);
         let inline src2 = select(first_step, (index + 1) % 32 / 2, index * 2 + 1);
-        let inline c1 = (src1 * 4 + channel)?(120+320*240+192*4);
+        let inline c1 = (src1 * 4 + channel)?SWEETY;
-        let inline c2 = (src2 * 4 + channel)?(120+320*240+192*4);
+        let inline c2 = (src2 * 4 + channel)?SWEETY;
-        i?(120+320*240+192*4) = (c1 + c2) * (3 + first_step) / 8;
+        i?SWEETY = (c1 + c2) * (3 + first_step) / 8;
 
         branch_if (i := i - 1) >= 0: expand_sweetie;
     }
 }
 
-data 120+320*240+192*4 {
+data SWEETY {
     i32(
         0x2c1c1a,
         0x5d275d,

examples/microw8/print.cwa

@@ -0,0 +1,24 @@
+import "env.memory" memory(4);
+import "env.printString" fn printString(i32);
+import "env.printChar" fn printChar(i32);
+
+export fn upd() {
+    printChar(12);
+    printChar('Test');
+    printChar('\1f\10\10');
+    printChar('abc\n');
+    printString(0);
+
+    let t = 32!32 / 1000 #% 3;
+    if t == 0 {
+        printChar('one');
+    } else if t == 1 {
+        printChar('two');
+    } else {
+        printChar('many');
+    }
+}
+
+data 0 {
+    "\0e\64\"Colors!!!\"\0e\1\r\n\0"
+}

examples/microw8/technotunnel.cwa

@@ -1,24 +1,29 @@
 import "env.memory" memory(4);
 import "env.sin" fn sin(f32) -> f32;
+import "env.time" fn time() -> f32;
+import "env.setPixel" fn setPixel(i32, i32, i32);
 
-export fn tic(time: i32) {
+export fn upd() {
-    let i: i32;
+    let x: i32;
+    let y: i32;
     loop screen {
-        let lazy t = time as f32 / 2000 as f32;
+        let inline t = time() / 2 as f32;
-        let lazy o = sin(t) * 0.8;
+        let lazy o = sin(t) * 0.75;
-        let lazy q = (i % 320) as f32 - 160.1;
+        let inline q = x as f32 - 160.5;
-        let lazy w = (i / 320 - 120) as f32;
+        let inline w = (y - 120) as f32;
         let lazy r = sqrt(q*q + w*w);
         let lazy z = q / r;
         let lazy s = z * o + sqrt(z * z * o * o + 1 as f32 - o * o);
-        let lazy q2 = (z * s - o) * 10 as f32 + t;
+        let inline q2 = (z * s - o) * 10 as f32 + t;
-        let lazy w2 = w / r * s * 10 as f32 + t;
+        let inline w2 = w / r * s * 10 as f32 + t;
-        let lazy s2 = s * 50 as f32 / r;
+        let inline s2 = s * 100 as f32 / r;
-        i?120 = max(
+        let inline color = max(
             0 as f32, 
-            ((q2 as i32 ^ w2 as i32 & ((s2 + t) * 20 as f32) as i32) & 5) as f32 *
+            ((q2 as i32 ^ w2 as i32 & ((s2 + time()) * 10 as f32) as i32) & 5) as f32 *
-                (2 as f32 - s2) * 22 as f32
+                (4 as f32 - s2) as f32
-            ) as i32;
+            ) as i32 - 32;
-        branch_if (i := i + 1) < 320*240: screen
+        setPixel(x, y, color);
+        branch_if x := (x + 1) % 320: screen;
+        branch_if y := (y + 1) % 320: screen;
     }
 }

examples/microw8/uw8.cwa

@@ -0,0 +1,13 @@
+import "env.memory" memory(4);
+
+import "env.pow" fn pow(f32, f32) -> f32;
+import "env.sin" fn sin(f32) -> f32;
+import "env.cos" fn cos(f32) -> f32;
+import "env.atan2" fn atan2(f32, f32) -> f32;
+import "env.tan" fn tan(f32) -> f32;
+import "env.atan" fn atan(f32) -> f32;
+import "env.rectangle" fn rect(f32, f32, f32, f32, i32);
+
+const FRAMEBUFFER = 120;
+const PALETTE = 0x13000;
+const FONT = 0x13400;

examples/microw8/warptunnel.cwa

@@ -1,15 +1,16 @@
 import "env.memory" memory(2);
+import "env.time" fn time() -> f32;
 
-export fn tic(time: i32) {
+export fn upd() {
     let i: i32;
     loop pixels {
         let lazy x = (i % 320) as f32 - 160.1;
         let lazy y = (i / 320 - 120) as f32;
-        let lazy dist = 10000.0 / (x*x + y*y);
+        let lazy dist = 1024_f / (x*x + y*y);
-        let lazy t = time as f32 / 20 as f32;
+        let inline t = time() * 4_f;
 
-        i?120 = (x * dist + t) as i32 ^ (y * dist + t) as i32;
+        i?120 = (x * dist + t) as i32 ^ (y * dist + t) as i32 | -32;
 
-        branch_if (i := i + 1) < 320*240: pixels
+        branch_if (i +:= 1) < 320*240: pixels
     }
 }

examples/wasm4/skipahead.cwa

@@ -18,14 +18,14 @@ fn rng(state: i32) -> i32 {
 }
 
 fn set_color(color: i32) -> i32 {
-    ?20 = color;
+    0?20 = color;
     6
 }
 
 export fn update() {
     let y: i32;
     let score = pz;
-    let lazy pad = ?22;
+    let lazy pad = 0?22;
     let lazy zero = 0.0;
 
     let lazy control_speed = 0.03;
@@ -33,7 +33,7 @@ export fn update() {
     f = f * 0.7;
 
     loop lines {
-        ?(8003-y) = (score := score / 10) % 10 + 48;
+        (8003-y)?0 = (score := score / 10) % 10 + 48;
         let lazy z = (4000 / (y := y + 1) + pz) / 20;
         let lazy x = (rng(rng(rng(rng(z)))) >> 30) as f32 - px;
         let lazy w = 9 as f32 / sqrt(z as f32);

src/ast.rs

@@ -1,13 +1,26 @@
 use std::{fmt, path::PathBuf};
 
-use crate::Span;
+use crate::parser::Span;
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct Script {
     pub imports: Vec<Import>,
     pub global_vars: Vec<GlobalVar>,
     pub functions: Vec<Function>,
     pub data: Vec<Data>,
+    pub includes: Vec<Include>,
+    pub consts: Vec<GlobalConst>,
+}
+
+impl Script {
+    pub fn merge(&mut self, mut other: Script) {
+        self.imports.append(&mut other.imports);
+        self.global_vars.append(&mut other.global_vars);
+        self.functions.append(&mut other.functions);
+        self.data.append(&mut other.data);
+        self.consts.append(&mut other.consts);
+        assert!(other.includes.is_empty());
+    }
 }
 
 #[derive(Debug)]
@@ -16,6 +29,14 @@ pub enum TopLevelItem {
     GlobalVar(GlobalVar),
     Function(Function),
     Data(Data),
+    Include(Include),
+    Const(GlobalConst),
+}
+
+#[derive(Debug)]
+pub struct Include {
+    pub span: Span,
+    pub path: String,
 }
 
 #[derive(Debug)]
@@ -49,6 +70,14 @@ pub struct GlobalVar {
     pub mutable: bool,
 }
 
+#[derive(Debug)]
+pub struct GlobalConst {
+    pub span: Span,
+    pub name: String,
+    pub value: Expression,
+    pub type_: Option<Type>,
+}
+
 #[derive(Debug)]
 pub struct Function {
     pub span: Span,
@@ -152,7 +181,7 @@ pub enum DataType {
     F64,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct MemoryLocation {
     pub span: Span,
     pub size: MemSize,
@@ -160,7 +189,7 @@ pub struct MemoryLocation {
     pub right: Box<Expression>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Expression {
     pub type_: Option<Type>,
     pub expr: Expr,
@@ -195,9 +224,16 @@ impl Expression {
             _ => panic!("Expected F64Const"),
         }
     }
+
+    pub fn is_const(&self) -> bool {
+        match self.expr {
+            Expr::I32Const(_) | Expr::I64Const(_) | Expr::F32Const(_) | Expr::F64Const(_) => true,
+            _ => false,
+        }
+    }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum Expr {
     Block {
         statements: Vec<Expression>,
@@ -337,7 +373,7 @@ pub enum BinOp {
 pub enum MemSize {
     Byte,
     Word,
-    Float
+    Float,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]

src/constfold.rs

@@ -1,35 +1,103 @@
-use crate::ast;
+use std::collections::HashMap;
+
+use crate::{
+    ast,
+    parser::{Sources, Span},
+    typecheck::{report_duplicate_definition, report_error},
+};
+
+type Result<T> = std::result::Result<T, ()>;
+
+pub fn fold_script(script: &mut ast::Script, sources: &Sources) -> Result<()> {
+    let mut context = Context {
+        consts: HashMap::new(),
+        sources,
+    };
+    fold_consts(&mut context, &mut script.consts)?;
 
-pub fn fold_script(script: &mut ast::Script) {
     for var in &mut script.global_vars {
-        fold_expr(&mut var.value);
+        fold_expr(&context, &mut var.value);
     }
 
     for func in &mut script.functions {
-        fold_expr(&mut func.body);
+        fold_expr(&context, &mut func.body);
     }
 
     for data in &mut script.data {
-        fold_expr(&mut data.offset);
+        fold_expr(&context, &mut data.offset);
         for values in &mut data.data {
             match values {
                 ast::DataValues::Array { values, .. } => {
                     for value in values {
-                        fold_expr(value);
+                        fold_expr(&context, value);
                     }
                 }
                 ast::DataValues::String(_) | ast::DataValues::File { .. } => (),
             }
         }
     }
+
+    Ok(())
 }
 
-fn fold_mem_location(mem_location: &mut ast::MemoryLocation) {
+struct Context<'a> {
-    fold_expr(&mut mem_location.left);
+    consts: HashMap<String, ast::Expr>,
-    fold_expr(&mut mem_location.right);
+    sources: &'a Sources,
 }
 
-fn fold_expr(expr: &mut ast::Expression) {
+fn fold_consts(context: &mut Context, consts: &mut [ast::GlobalConst]) -> Result<()> {
+    let mut spans: HashMap<&str, Span> = HashMap::new();
+
+    for cnst in consts.iter_mut() {
+        if let Some(prev_span) = spans.insert(&cnst.name, cnst.span.clone()) {
+            report_duplicate_definition(
+                "Const already defined",
+                &cnst.span,
+                &prev_span,
+                context.sources,
+            )?;
+        }
+    }
+
+    while context.consts.len() < consts.len() {
+        let mut making_progress = false;
+        for cnst in consts.iter_mut() {
+            if !context.consts.contains_key(&cnst.name) {
+                fold_expr(context, &mut cnst.value);
+                if cnst.value.is_const() {
+                    context
+                        .consts
+                        .insert(cnst.name.clone(), cnst.value.expr.clone());
+                    making_progress = true;
+                }
+            }
+        }
+
+        if !making_progress {
+            break;
+        }
+    }
+
+    let mut result = Ok(());
+    for cnst in consts {
+        if !context.consts.contains_key(&cnst.name) {
+            result = report_error(
+                &format!("Failed to fold const '{}'", cnst.name),
+                &cnst.span,
+                context.sources,
+            );
+        }
+    }
+
+    result
+}
+
+fn fold_mem_location(context: &Context, mem_location: &mut ast::MemoryLocation) {
+    fold_expr(context, &mut mem_location.left);
+    fold_expr(context, &mut mem_location.right);
+}
+
+fn fold_expr(context: &Context, expr: &mut ast::Expression) {
     use ast::BinOp::*;
     match expr.expr {
         ast::Expr::Block {
@@ -37,15 +105,15 @@ fn fold_expr(expr: &mut ast::Expression) {
             ref mut final_expression,
         } => {
             for stmt in statements {
-                fold_expr(stmt);
+                fold_expr(context, stmt);
             }
             if let Some(ref mut expr) = final_expression {
-                fold_expr(expr);
+                fold_expr(context, expr);
             }
         }
         ast::Expr::Let { ref mut value, .. } => {
             if let Some(ref mut expr) = value {
-                fold_expr(expr);
+                fold_expr(context, expr);
             }
         }
         ast::Expr::Poke {
@@ -53,12 +121,12 @@ fn fold_expr(expr: &mut ast::Expression) {
             ref mut value,
             ..
         } => {
-            fold_mem_location(mem_location);
+            fold_mem_location(context, mem_location);
-            fold_expr(value);
+            fold_expr(context, value);
         }
-        ast::Expr::Peek(ref mut mem_location) => fold_mem_location(mem_location),
+        ast::Expr::Peek(ref mut mem_location) => fold_mem_location(context, mem_location),
         ast::Expr::UnaryOp { op, ref mut value } => {
-            fold_expr(value);
+            fold_expr(context, value);
             let result = match (op, &value.expr) {
                 (ast::UnaryOp::Negate, ast::Expr::I32Const(value)) => {
                     Some(ast::Expr::I32Const(-*value))
@@ -72,6 +140,20 @@ fn fold_expr(expr: &mut ast::Expression) {
                 (ast::UnaryOp::Negate, ast::Expr::F64Const(value)) => {
                     Some(ast::Expr::F64Const(-*value))
                 }
+                (ast::UnaryOp::Negate, ast::Expr::Cast { value, type_ }) => {
+                    if let ast::Expr::I32Const(v) = value.expr {
+                        Some(ast::Expr::Cast {
+                            value: Box::new(ast::Expression {
+                                expr: ast::Expr::I32Const(-v),
+                                span: value.span.clone(),
+                                type_: value.type_,
+                            }),
+                            type_: *type_,
+                        })
+                    } else {
+                        None
+                    }
+                }
                 (ast::UnaryOp::Not, ast::Expr::I32Const(value)) => {
                     Some(ast::Expr::I32Const((*value == 0) as i32))
                 }
@@ -90,8 +172,8 @@ fn fold_expr(expr: &mut ast::Expression) {
             ref mut right,
             ..
         } => {
-            fold_expr(left);
+            fold_expr(context, left);
-            fold_expr(right);
+            fold_expr(context, right);
             match (&left.expr, &right.expr) {
                 (&ast::Expr::I32Const(left), &ast::Expr::I32Const(right)) => {
                     let result = match op {
@@ -237,24 +319,28 @@ fn fold_expr(expr: &mut ast::Expression) {
         ast::Expr::I32Const(_)
         | ast::Expr::I64Const(_)
         | ast::Expr::F32Const(_)
-        | ast::Expr::F64Const(_)
+        | ast::Expr::F64Const(_) => (),
-        | ast::Expr::Variable { .. } => (),
+        ast::Expr::Variable { ref name, .. } => {
-        ast::Expr::Assign { ref mut value, .. } => fold_expr(value),
+            if let Some(value) = context.consts.get(name) {
-        ast::Expr::LocalTee { ref mut value, .. } => fold_expr(value),
+                expr.expr = value.clone();
-        ast::Expr::Loop { ref mut block, .. } => fold_expr(block),
+            }
-        ast::Expr::LabelBlock { ref mut block, .. } => fold_expr(block),
+        }
+        ast::Expr::Assign { ref mut value, .. } => fold_expr(context, value),
+        ast::Expr::LocalTee { ref mut value, .. } => fold_expr(context, value),
+        ast::Expr::Loop { ref mut block, .. } => fold_expr(context, block),
+        ast::Expr::LabelBlock { ref mut block, .. } => fold_expr(context, block),
         ast::Expr::Branch(_) => (),
         ast::Expr::BranchIf {
             ref mut condition, ..
-        } => fold_expr(condition),
+        } => fold_expr(context, condition),
-        ast::Expr::Cast { ref mut value, .. } => fold_expr(value),
+        ast::Expr::Cast { ref mut value, .. } => fold_expr(context, value),
         ast::Expr::FuncCall {
             ref name,
             ref mut params,
             ..
         } => {
             for param in params.iter_mut() {
-                fold_expr(param);
+                fold_expr(context, param);
             }
             use ast::Expr::*;
             let params: Vec<_> = params.iter().map(|e| &e.expr).collect();
@@ -269,31 +355,31 @@ fn fold_expr(expr: &mut ast::Expression) {
             ref mut if_false,
             ..
         } => {
-            fold_expr(condition);
+            fold_expr(context, condition);
-            fold_expr(if_true);
+            fold_expr(context, if_true);
-            fold_expr(if_false);
+            fold_expr(context, if_false);
         }
         ast::Expr::If {
             ref mut condition,
             ref mut if_true,
             ref mut if_false,
         } => {
-            fold_expr(condition);
+            fold_expr(context, condition);
-            fold_expr(if_true);
+            fold_expr(context, if_true);
             if let Some(ref mut if_false) = if_false {
-                fold_expr(if_false);
+                fold_expr(context, if_false);
             }
         }
         ast::Expr::Return {
             value: Some(ref mut value),
-        } => fold_expr(value),
+        } => fold_expr(context, value),
         ast::Expr::Return { value: None } => (),
         ast::Expr::First {
             ref mut value,
             ref mut drop,
         } => {
-            fold_expr(value);
+            fold_expr(context, value);
-            fold_expr(drop);
+            fold_expr(context, drop);
         }
         ast::Expr::Error => unreachable!(),
     }

src/emit.rs

@@ -289,7 +289,7 @@ struct FunctionContext<'a> {
     functions: &'a HashMap<String, u32>,
     locals: &'a ast::Locals,
     labels: Vec<String>,
-    let_values: HashMap<u32, (&'a ast::Expression, ast::LetType)>,
+    let_values: HashMap<u32, Vec<(&'a ast::Expression, ast::LetType)>>,
     intrinsics: &'a Intrinsics,
 }
 
@@ -385,7 +385,10 @@ fn emit_expression<'a>(ctx: &mut FunctionContext<'a>, expr: &'a ast::Expression)
                             .instruction(&Instruction::LocalSet(local.index.unwrap()));
                     }
                     ast::LetType::Lazy | ast::LetType::Inline => {
-                        ctx.let_values.insert(local_id.unwrap(), (value, *let_type));
+                        ctx.let_values
+                            .entry(local_id.unwrap())
+                            .or_default()
+                            .push((value, *let_type));
                     }
                 }
             }
@@ -612,17 +615,17 @@ fn emit_expression<'a>(ctx: &mut FunctionContext<'a>, expr: &'a ast::Expression)
         }
         ast::Expr::Variable { name, local_id } => {
             if let &Some(id) = local_id {
-                if let Some((expr, let_type)) = ctx.let_values.get(&id) {
+                if let Some((expr, let_type)) = ctx.let_values.get_mut(&id).and_then(|s| s.pop()) {
                     match let_type {
                         ast::LetType::Lazy => {
-                            let expr = ctx.let_values.remove(&id).unwrap().0;
                             emit_expression(ctx, expr);
+                            ctx.let_values.get_mut(&id).unwrap().clear();
                             ctx.function
                                 .instruction(&Instruction::LocalTee(ctx.locals[id].index.unwrap()));
                         }
                         ast::LetType::Inline => {
-                            let expr = *expr;
                             emit_expression(ctx, expr);
+                            ctx.let_values.get_mut(&id).unwrap().push((expr, let_type));
                         }
                         _ => unreachable!(),
                     }

src/includes.rs

@@ -1,11 +1,15 @@
-use std::fs::File;
 use std::io::prelude::*;
-use std::path::Path;
+use std::path::{Path, PathBuf};
+use std::{collections::HashSet, fs::File};
 
 use crate::ast;
 use anyhow::{anyhow, Result};
 
-pub fn resolve_includes(script: &mut ast::Script, path: &Path) -> Result<()> {
+pub fn resolve_includes(
+    script: &mut ast::Script,
+    dependencies: &mut HashSet<PathBuf>,
+    path: &Path,
+) -> Result<()> {
     let script_dir = path.parent().expect("Script path has no parent");
     for data in &mut script.data {
         for values in &mut data.data {
@@ -21,6 +25,7 @@ pub fn resolve_includes(script: &mut ast::Script, path: &Path) -> Result<()> {
                         anyhow!("Failed to load data from {}: {}", full_path.display(), e)
                     })?
                     .read_to_end(data)?;
+                dependencies.insert(full_path);
             }
         }
     }

src/intrinsics.rs

@@ -1,9 +1,11 @@
 use crate::ast::Type;
-use std::collections::HashMap;
 use enc::MemArg;
+use std::collections::HashMap;
 use wasm_encoder as enc;
 
-pub struct Intrinsics(HashMap<String, HashMap<Vec<Type>, (Type, enc::Instruction<'static>)>>);
+pub struct Intrinsics(
+    HashMap<String, HashMap<Vec<Type>, (Option<Type>, enc::Instruction<'static>)>>,
+);
 
 impl Intrinsics {
     pub fn new() -> Intrinsics {
@@ -12,14 +14,11 @@ impl Intrinsics {
         i
     }
 
-    pub fn find_types(
+    pub fn find_types(&self, name: &str) -> Option<HashMap<Vec<Type>, Option<Type>>> {
-        &self,
-        name: &str,
-    ) -> Option<HashMap<Vec<Type>, Option<Type>>> {
         self.0.get(name).map(|types| {
             types
                 .iter()
-                .map(|(params, (ret, _))| (params.clone(), Some(*ret)))
+                .map(|(params, (ret, _))| (params.clone(), *ret))
                 .collect()
         })
     }
@@ -34,87 +33,121 @@ impl Intrinsics {
     fn add_instructions(&mut self) {
         use enc::Instruction as I;
         use Type::*;
-        self.inst("i32.rotl", &[I32, I32], I32, I::I32Rotl);
+        self.inst("i32.rotl", &[I32, I32], Some(I32), I::I32Rotl);
-        self.inst("i32.rotr", &[I32, I32], I32, I::I32Rotr);
+        self.inst("i32.rotr", &[I32, I32], Some(I32), I::I32Rotr);
-        self.inst("i32.clz", &[I32], I32, I::I32Clz);
+        self.inst("i32.clz", &[I32], Some(I32), I::I32Clz);
-        self.inst("i32.ctz", &[I32], I32, I::I32Ctz);
+        self.inst("i32.ctz", &[I32], Some(I32), I::I32Ctz);
-        self.inst("i32.popcnt", &[I32], I32, I::I32Popcnt);
+        self.inst("i32.popcnt", &[I32], Some(I32), I::I32Popcnt);
 
-        self.inst("i64.rotl", &[I64, I64], I64, I::I64Rotl);
+        self.inst("i64.rotl", &[I64, I64], Some(I64), I::I64Rotl);
-        self.inst("i64.rotr", &[I64, I64], I64, I::I64Rotr);
+        self.inst("i64.rotr", &[I64, I64], Some(I64), I::I64Rotr);
-        self.inst("i64.clz", &[I64], I64, I::I64Clz);
+        self.inst("i64.clz", &[I64], Some(I64), I::I64Clz);
-        self.inst("i64.ctz", &[I64], I64, I::I64Ctz);
+        self.inst("i64.ctz", &[I64], Some(I64), I::I64Ctz);
-        self.inst("i64.popcnt", &[I64], I64, I::I64Popcnt);
+        self.inst("i64.popcnt", &[I64], Some(I64), I::I64Popcnt);
 
-        self.inst("f32/sqrt", &[F32], F32, I::F32Sqrt);
+        self.inst("f32/sqrt", &[F32], Some(F32), I::F32Sqrt);
-        self.inst("f32/min", &[F32, F32], F32, I::F32Min);
+        self.inst("f32/min", &[F32, F32], Some(F32), I::F32Min);
-        self.inst("f32/max", &[F32, F32], F32, I::F32Max);
+        self.inst("f32/max", &[F32, F32], Some(F32), I::F32Max);
-        self.inst("f32/ceil", &[F32], F32, I::F32Ceil);
+        self.inst("f32/ceil", &[F32], Some(F32), I::F32Ceil);
-        self.inst("f32/floor", &[F32], F32, I::F32Floor);
+        self.inst("f32/floor", &[F32], Some(F32), I::F32Floor);
-        self.inst("f32/trunc", &[F32], F32, I::F32Trunc);
+        self.inst("f32/trunc", &[F32], Some(F32), I::F32Trunc);
-        self.inst("f32/nearest", &[F32], F32, I::F32Nearest);
+        self.inst("f32/nearest", &[F32], Some(F32), I::F32Nearest);
-        self.inst("f32/abs", &[F32], F32, I::F32Abs);
+        self.inst("f32/abs", &[F32], Some(F32), I::F32Abs);
-        self.inst("f32.copysign", &[F32, F32], F32, I::F32Copysign);
+        self.inst("f32.copysign", &[F32, F32], Some(F32), I::F32Copysign);
 
-        self.inst("f64/sqrt", &[F64], F64, I::F64Sqrt);
+        self.inst("f64/sqrt", &[F64], Some(F64), I::F64Sqrt);
-        self.inst("f64/min", &[F64, F64], F64, I::F64Min);
+        self.inst("f64/min", &[F64, F64], Some(F64), I::F64Min);
-        self.inst("f64/max", &[F64, F64], F64, I::F64Max);
+        self.inst("f64/max", &[F64, F64], Some(F64), I::F64Max);
-        self.inst("f64/ceil", &[F64], F64, I::F64Ceil);
+        self.inst("f64/ceil", &[F64], Some(F64), I::F64Ceil);
-        self.inst("f64/floor", &[F64], F64, I::F64Floor);
+        self.inst("f64/floor", &[F64], Some(F64), I::F64Floor);
-        self.inst("f64/trunc", &[F64], F64, I::F64Trunc);
+        self.inst("f64/trunc", &[F64], Some(F64), I::F64Trunc);
-        self.inst("f64/nearest", &[F64], F64, I::F64Nearest);
+        self.inst("f64/nearest", &[F64], Some(F64), I::F64Nearest);
-        self.inst("f64/abs", &[F64], F64, I::F64Abs);
+        self.inst("f64/abs", &[F64], Some(F64), I::F64Abs);
-        self.inst("f64.copysign", &[F64, F64], F64, I::F64Copysign);
+        self.inst("f64.copysign", &[F64, F64], Some(F64), I::F64Copysign);
 
-        self.inst("i32.wrap_i64", &[I64], I32, I::I32WrapI64);
+        self.inst("i32.wrap_i64", &[I64], Some(I32), I::I32WrapI64);
-        self.inst("i64.extend_i32_s", &[I32], I64, I::I64ExtendI32S);
+        self.inst("i64.extend_i32_s", &[I32], Some(I64), I::I64ExtendI32S);
-        self.inst("i64.extend_i32_u", &[I32], I64, I::I64ExtendI32U);
+        self.inst("i64.extend_i32_u", &[I32], Some(I64), I::I64ExtendI32U);
 
-        self.inst("i32.trunc_f32_s", &[F32], I32, I::I32TruncF32S);
+        self.inst("i32.trunc_f32_s", &[F32], Some(I32), I::I32TruncF32S);
-        self.inst("i32.trunc_f64_s", &[F64], I32, I::I32TruncF64S);
+        self.inst("i32.trunc_f64_s", &[F64], Some(I32), I::I32TruncF64S);
-        self.inst("i64.trunc_f32_s", &[F32], I64, I::I64TruncF32S);
+        self.inst("i64.trunc_f32_s", &[F32], Some(I64), I::I64TruncF32S);
-        self.inst("i64.trunc_f64_s", &[F64], I64, I::I64TruncF64S);
+        self.inst("i64.trunc_f64_s", &[F64], Some(I64), I::I64TruncF64S);
 
-        self.inst("i32.trunc_f32_u", &[F32], I32, I::I32TruncF32U);
+        self.inst("i32.trunc_f32_u", &[F32], Some(I32), I::I32TruncF32U);
-        self.inst("i32.trunc_f64_u", &[F64], I32, I::I32TruncF64U);
+        self.inst("i32.trunc_f64_u", &[F64], Some(I32), I::I32TruncF64U);
-        self.inst("i64.trunc_f32_u", &[F32], I64, I::I64TruncF32U);
+        self.inst("i64.trunc_f32_u", &[F32], Some(I64), I::I64TruncF32U);
-        self.inst("i64.trunc_f64_u", &[F64], I64, I::I64TruncF64U);
+        self.inst("i64.trunc_f64_u", &[F64], Some(I64), I::I64TruncF64U);
 
-        self.inst("f32.demote_f64", &[F64], F32, I::F32DemoteF64);
+        self.inst("f32.demote_f64", &[F64], Some(F32), I::F32DemoteF64);
-        self.inst("f64.promote_f32", &[F32], F64, I::F64PromoteF32);
+        self.inst("f64.promote_f32", &[F32], Some(F64), I::F64PromoteF32);
 
-        self.inst("f32.convert_i32_s", &[I32], F32, I::F32ConvertI32S);
+        self.inst("f32.convert_i32_s", &[I32], Some(F32), I::F32ConvertI32S);
-        self.inst("f32.convert_i64_s", &[I64], F32, I::F32ConvertI32S);
+        self.inst("f32.convert_i64_s", &[I64], Some(F32), I::F32ConvertI32S);
-        self.inst("f64.convert_i32_s", &[I32], F64, I::F32ConvertI32S);
+        self.inst("f64.convert_i32_s", &[I32], Some(F64), I::F32ConvertI32S);
-        self.inst("f64.convert_i64_s", &[I64], F64, I::F32ConvertI32S);
+        self.inst("f64.convert_i64_s", &[I64], Some(F64), I::F32ConvertI32S);
 
-        self.inst("f32.convert_i32_u", &[I32], F32, I::F32ConvertI32U);
+        self.inst("f32.convert_i32_u", &[I32], Some(F32), I::F32ConvertI32U);
-        self.inst("f32.convert_i64_u", &[I64], F32, I::F32ConvertI32U);
+        self.inst("f32.convert_i64_u", &[I64], Some(F32), I::F32ConvertI32U);
-        self.inst("f64.convert_i32_u", &[I32], F64, I::F32ConvertI32U);
+        self.inst("f64.convert_i32_u", &[I32], Some(F64), I::F32ConvertI32U);
-        self.inst("f64.convert_i64_u", &[I64], F64, I::F32ConvertI32U);
+        self.inst("f64.convert_i64_u", &[I64], Some(F64), I::F32ConvertI32U);
 
-        self.inst("i32.reinterpret_f32", &[F32], I32, I::I32ReinterpretF32);
+        self.inst(
-        self.inst("i64.reinterpret_f64", &[F64], I64, I::I64ReinterpretF64);
+            "i32.reinterpret_f32",
-        self.inst("f32.reinterpret_i32", &[I32], F32, I::F32ReinterpretI32);
+            &[F32],
-        self.inst("f64.reinterpret_i64", &[I64], F64, I::F64ReinterpretI64);
+            Some(I32),
+            I::I32ReinterpretF32,
+        );
+        self.inst(
+            "i64.reinterpret_f64",
+            &[F64],
+            Some(I64),
+            I::I64ReinterpretF64,
+        );
+        self.inst(
+            "f32.reinterpret_i32",
+            &[I32],
+            Some(F32),
+            I::F32ReinterpretI32,
+        );
+        self.inst(
+            "f64.reinterpret_i64",
+            &[I64],
+            Some(F64),
+            I::F64ReinterpretI64,
+        );
 
-        self.inst("i32.extend8_s", &[I32], I32, I::I32Extend8S);
+        self.inst("i32.extend8_s", &[I32], Some(I32), I::I32Extend8S);
-        self.inst("i32.extend16_s", &[I32], I32, I::I32Extend16S);
+        self.inst("i32.extend16_s", &[I32], Some(I32), I::I32Extend16S);
-        self.inst("i64.extend8_s", &[I64], I64, I::I64Extend8S);
+        self.inst("i64.extend8_s", &[I64], Some(I64), I::I64Extend8S);
-        self.inst("i64.extend16_s", &[I64], I64, I::I64Extend16S);
+        self.inst("i64.extend16_s", &[I64], Some(I64), I::I64Extend16S);
-        self.inst("i64.extend32_s", &[I64], I64, I::I64Extend32S);
+        self.inst("i64.extend32_s", &[I64], Some(I64), I::I64Extend32S);
 
-        self.inst("i32.trunc_sat_f32_s", &[F32], I32, I::I32TruncSatF32S);
+        self.inst("i32.trunc_sat_f32_s", &[F32], Some(I32), I::I32TruncSatF32S);
-        self.inst("i32.trunc_sat_f32_u", &[F32], I32, I::I32TruncSatF32U);
+        self.inst("i32.trunc_sat_f32_u", &[F32], Some(I32), I::I32TruncSatF32U);
-        self.inst("i32.trunc_sat_f64_s", &[F64], I32, I::I32TruncSatF64S);
+        self.inst("i32.trunc_sat_f64_s", &[F64], Some(I32), I::I32TruncSatF64S);
-        self.inst("i32.trunc_sat_f64_u", &[F64], I32, I::I32TruncSatF64U);
+        self.inst("i32.trunc_sat_f64_u", &[F64], Some(I32), I::I32TruncSatF64U);
-        self.inst("i64.trunc_sat_f32_s", &[F32], I64, I::I64TruncSatF32S);
+        self.inst("i64.trunc_sat_f32_s", &[F32], Some(I64), I::I64TruncSatF32S);
-        self.inst("i64.trunc_sat_f32_u", &[F32], I64, I::I64TruncSatF32U);
+        self.inst("i64.trunc_sat_f32_u", &[F32], Some(I64), I::I64TruncSatF32U);
-        self.inst("i64.trunc_sat_f64_s", &[F64], I64, I::I64TruncSatF64S);
+        self.inst("i64.trunc_sat_f64_s", &[F64], Some(I64), I::I64TruncSatF64S);
-        self.inst("i64.trunc_sat_f64_u", &[F64], I64, I::I64TruncSatF64U);
+        self.inst("i64.trunc_sat_f64_u", &[F64], Some(I64), I::I64TruncSatF64U);
+
+        self.inst(
+            "memory.copy",
+            &[I32, I32, I32],
+            None,
+            I::MemoryCopy { src: 0, dst: 0 },
+        );
+        self.inst("memory.fill", &[I32, I32, I32], None, I::MemoryFill(0));
     }
 
-    fn inst(&mut self, name: &str, params: &[Type], ret: Type, ins: enc::Instruction<'static>) {
+    fn inst(
+        &mut self,
+        name: &str,
+        params: &[Type],
+        ret: Option<Type>,
+        ins: enc::Instruction<'static>,
+    ) {
         if let Some(slash_idx) = name.find('/') {
             self.insert(name[(slash_idx + 1)..].to_string(), params, ret, &ins);
             let mut full_name = name[..slash_idx].to_string();
@@ -130,7 +163,7 @@ impl Intrinsics {
         &mut self,
         name: String,
         params: &[Type],
-        ret: Type,
+        ret: Option<Type>,
         ins: &enc::Instruction<'static>,
     ) {
         self.0
@@ -157,7 +190,7 @@ impl Intrinsics {
             "i64.load32_u" => MemInstruction::new(I64, I::I64Load32_U, 2),
             "f32.load" => MemInstruction::new(F32, I::F32Load, 2),
             "f64.load" => MemInstruction::new(F64, I::F64Load, 3),
-            _ => return None
+            _ => return None,
         };
         return Some(ins);
     }
@@ -175,7 +208,7 @@ impl Intrinsics {
             "i64.store32" => MemInstruction::new(I64, I::I64Store32, 2),
             "f32.store" => MemInstruction::new(F32, I::F32Store, 2),
             "f64.store" => MemInstruction::new(F64, I::F64Store, 3),
-            _ => return None
+            _ => return None,
         };
         return Some(ins);
     }
@@ -184,13 +217,19 @@ impl Intrinsics {
 pub struct MemInstruction {
     pub type_: Type,
     pub instruction: fn(MemArg) -> enc::Instruction<'static>,
-    pub natural_alignment: u32
+    pub natural_alignment: u32,
 }
 
 impl MemInstruction {
-    fn new(type_: Type, instruction: fn(MemArg) -> enc::Instruction<'static>, natural_alignment: u32) -> MemInstruction {
+    fn new(
+        type_: Type,
+        instruction: fn(MemArg) -> enc::Instruction<'static>,
+        natural_alignment: u32,
+    ) -> MemInstruction {
         MemInstruction {
-            type_, instruction, natural_alignment
+            type_,
+            instruction,
+            natural_alignment,
         }
     }
 }

src/lib.rs

@@ -1,7 +1,8 @@
 use anyhow::{bail, Result};
+use parser::Sources;
+use std::collections::HashSet;
 use std::ffi::OsStr;
-use std::io::prelude::*;
+use std::path::{Path, PathBuf};
-use std::{fs::File, path::Path};
 
 mod ast;
 mod constfold;
@@ -11,8 +12,6 @@ mod intrinsics;
 mod parser;
 mod typecheck;
 
-type Span = std::ops::Range<usize>;
-
 #[derive(Default)]
 pub struct Options {
     pub(crate) debug: bool,
@@ -24,24 +23,60 @@ impl Options {
     }
 }
 
-pub fn compile_file<P: AsRef<Path>>(path: P, options: Options) -> Result<Vec<u8>> {
+pub struct CompiledModule {
-    let path = path.as_ref();
+    pub wasm: Vec<u8>,
-    let mut input = String::new();
+    pub dependencies: Vec<PathBuf>,
-    File::open(path)?.read_to_string(&mut input)?;
-
-    compile_str(&input, path, options)
 }
 
-pub fn compile_str(input: &str, path: &Path, options: Options) -> Result<Vec<u8>> {
+pub fn compile_file<P: AsRef<Path>>(path: P, options: Options) -> (Result<Vec<u8>>, Vec<PathBuf>) {
-    let mut script = match parser::parse(input) {
+    fn compile_file_inner(
+        path: &Path,
+        options: Options,
+        dependencies: &mut HashSet<PathBuf>,
+    ) -> Result<Vec<u8>> {
+        let mut script = ast::Script::default();
+
+        let mut sources = Sources::new();
+
+        let mut pending_files = vec![(path.to_path_buf(), None)];
+        while let Some((path, span)) = pending_files.pop() {
+            match sources.add(&path) {
+                Ok((id, true)) => {
+                    dependencies.insert(path.clone());
+                    let mut new_script = match parser::parse(&sources, id) {
                         Ok(script) => script,
                         Err(_) => bail!("Parse failed"),
                     };
 
-    includes::resolve_includes(&mut script, path)?;
+                    includes::resolve_includes(&mut new_script, dependencies, &path)?;
 
-    constfold::fold_script(&mut script);
+                    for include in std::mem::take(&mut new_script.includes) {
-    if typecheck::tc_script(&mut script, input).is_err() {
+                        let mut path = path
+                            .parent()
+                            .expect("Script path has no parent")
+                            .to_path_buf();
+                        path.push(include.path);
+                        pending_files.push((path, Some(include.span)));
+                    }
+
+                    script.merge(new_script);
+                }
+                Ok((_, false)) => (), // already parsed this include
+                Err(err) => {
+                    if let Some(span) = span {
+                        let _ = typecheck::report_error(&err.to_string(), &span, &sources);
+                    } else {
+                        eprintln!("Failed to load script {}: {}", path.display(), err);
+                    }
+                    bail!("Parse failed");
+                }
+            }
+        }
+
+        if constfold::fold_script(&mut script, &sources).is_err() {
+            bail!("Constant folding failed");
+        }
+        if typecheck::tc_script(&mut script, &sources).is_err() {
             bail!("Type check failed");
         }
         let wasm = emit::emit(
@@ -54,3 +89,10 @@ pub fn compile_str(input: &str, path: &Path, options: Options) -> Result<Vec<u8>
         );
         Ok(wasm)
     }
+
+    let mut dependencies = HashSet::new();
+
+    let result = compile_file_inner(path.as_ref(), options, &mut dependencies);
+
+    (result, dependencies.into_iter().collect())
+}

src/main.rs

@@ -15,7 +15,7 @@ fn main() -> Result<()> {
 
     let mut filename = args.free_from_os_str::<PathBuf, bool>(|s| Ok(s.into()))?;
 
-    let wasm = compile_file(&filename, options)?;
+    let wasm = compile_file(&filename, options).0?;
 
     wasmparser::validate(&wasm)?;
 

src/parser.rs

@@ -1,8 +1,62 @@
 use crate::ast;
-use crate::Span;
+use anyhow::Result;
-use ariadne::{Color, Fmt, Label, Report, ReportKind, Source};
+use ariadne::{Color, Fmt, Label, Report, ReportKind};
-use chumsky::{prelude::*, stream::Stream};
+use chumsky::prelude::*;
-use std::fmt;
+use std::{
+    fmt,
+    fs::File,
+    io::Read,
+    ops::Range,
+    path::{Path, PathBuf},
+};
+
+pub type Span = (usize, Range<usize>);
+
+pub struct SourceFile {
+    source: ariadne::Source,
+    path: PathBuf,
+}
+
+pub struct Sources(Vec<SourceFile>);
+
+impl Sources {
+    pub fn new() -> Sources {
+        Sources(Vec::new())
+    }
+
+    pub fn add(&mut self, path: &Path) -> Result<(usize, bool)> {
+        let canonical = path.canonicalize()?;
+        for (index, source) in self.0.iter().enumerate() {
+            if source.path.canonicalize()? == canonical {
+                return Ok((index, false));
+            }
+        }
+        let mut source = String::new();
+        File::open(path)?.read_to_string(&mut source)?;
+        self.0.push(SourceFile {
+            source: ariadne::Source::from(source),
+            path: path.to_path_buf(),
+        });
+        Ok((self.0.len() - 1, true))
+    }
+}
+
+impl std::ops::Index<usize> for Sources {
+    type Output = SourceFile;
+    fn index(&self, idx: usize) -> &SourceFile {
+        &self.0[idx]
+    }
+}
+
+impl ariadne::Cache<usize> for &Sources {
+    fn fetch(&mut self, id: &usize) -> Result<&ariadne::Source, Box<dyn std::fmt::Debug + '_>> {
+        Ok(&self.0[*id].source)
+    }
+
+    fn display<'a>(&self, id: &'a usize) -> Option<Box<dyn std::fmt::Display + 'a>> {
+        Some(Box::new(self.0[*id].path.clone().display().to_string()))
+    }
+}
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 enum Token {
@@ -25,6 +79,7 @@ enum Token {
     Str(String),
     Int(i32),
     Int64(i64),
+    IntFloat(i32),
     Float(String),
     Float64(String),
     Op(String),
@@ -53,6 +108,7 @@ impl fmt::Display for Token {
             Token::Str(s) => write!(f, "{:?}", s),
             Token::Int(v) => write!(f, "{}", v),
             Token::Int64(v) => write!(f, "{}", v),
+            Token::IntFloat(v) => write!(f, "{}_f", v),
             Token::Float(v) => write!(f, "{}", v),
             Token::Float64(v) => write!(f, "{}", v),
             Token::Op(s) => write!(f, "{}", s),
@@ -61,8 +117,36 @@ impl fmt::Display for Token {
     }
 }
 
-pub fn parse(source: &str) -> Result<ast::Script, ()> {
+type SourceStream<It> = chumsky::Stream<'static, char, Span, It>;
-    let tokens = match lexer().parse(source) {
+type TokenStream<It> = chumsky::Stream<'static, Token, Span, It>;
+
+pub fn parse(sources: &Sources, source_id: usize) -> Result<ast::Script, ()> {
+    let source = &sources[source_id].source;
+    let source_stream = SourceStream::from_iter(
+        (source_id, source.len()..source.len() + 1),
+        Box::new(
+            // this is a bit of an ugly hack
+            // once the next version of ariadne is released
+            // use the source string chars as input
+            // and only create the ariadne::Source lazily when printing errors
+            source
+                .lines()
+                .flat_map(|l| {
+                    let mut chars: Vec<char> = l.chars().collect();
+                    while chars.len() + 1 < l.len() {
+                        chars.push(' ');
+                    }
+                    if chars.len() < l.len() {
+                        chars.push('\n');
+                    }
+                    chars.into_iter()
+                })
+                .enumerate()
+                .map(|(index, char)| (char, (source_id, index..(index + 1)))),
+        ),
+    );
+
+    let tokens = match lexer().parse(source_stream) {
         Ok(tokens) => tokens,
         Err(errors) => {
             report_errors(
@@ -70,15 +154,14 @@ pub fn parse(source: &str) -> Result<ast::Script, ()> {
                     .into_iter()
                     .map(|e| e.map(|c| c.to_string()))
                     .collect(),
-                source,
+                sources,
             );
             return Err(());
         }
     };
 
-    let source_len = source.chars().count();
+    let script = match script_parser().parse(TokenStream::from_iter(
-    let script = match script_parser().parse(Stream::from_iter(
+        (source_id, source.len()..source.len() + 1),
-        source_len..source_len + 1,
         tokens.into_iter(),
     )) {
         Ok(script) => script,
@@ -88,7 +171,7 @@ pub fn parse(source: &str) -> Result<ast::Script, ()> {
                     .into_iter()
                     .map(|e| e.map(|t| t.to_string()))
                     .collect(),
-                source,
+                sources,
             );
             return Err(());
         }
@@ -96,9 +179,9 @@ pub fn parse(source: &str) -> Result<ast::Script, ()> {
     Ok(script)
 }
 
-fn report_errors(errors: Vec<Simple<String>>, source: &str) {
+fn report_errors(errors: Vec<Simple<String, Span>>, sources: &Sources) {
     for error in errors {
-        let report = Report::build(ReportKind::Error, (), error.span().start());
+        let report = Report::build(ReportKind::Error, error.span().0, error.span().1.start());
 
         let report = match error.reason() {
             chumsky::error::SimpleReason::Unclosed { span, delimiter } => report
@@ -161,30 +244,31 @@ fn report_errors(errors: Vec<Simple<String>>, source: &str) {
             ),
         };
 
-        report.finish().eprint(Source::from(source)).unwrap();
+        report.finish().eprint(sources).unwrap();
     }
 }
 
-fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = Simple<char>> {
+type LexerError = Simple<char, Span>;
-    let float64 = text::int(10)
+fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = LexerError> {
+    let float64 = text::digits(10)
         .chain::<char, _, _>(just('.').chain(text::digits(10)))
         .then_ignore(just("f64"))
         .collect::<String>()
         .map(Token::Float64);
 
-    let float = text::int(10)
+    let float = text::digits(10)
         .chain::<char, _, _>(just('.').chain(text::digits(10)))
         .collect::<String>()
         .map(Token::Float);
 
-    let integer = just::<_, _, Simple<char>>("0x")
+    let integer = just::<_, _, LexerError>("0x")
-        .ignore_then(text::int(16))
+        .ignore_then(text::digits(16))
         .try_map(|n, span| {
-            u64::from_str_radix(&n, 16).map_err(|err| Simple::custom(span, err.to_string()))
+            u64::from_str_radix(&n, 16).map_err(|err| LexerError::custom(span, err.to_string()))
         })
-        .or(text::int(10).try_map(|n: String, span: Span| {
+        .or(text::digits(10).try_map(|n: String, span: Span| {
             n.parse::<u64>()
-                .map_err(|err| Simple::custom(span, err.to_string()))
+                .map_err(|err| LexerError::custom(span, err.to_string()))
         }))
         .boxed();
 
@@ -193,28 +277,73 @@ fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = Simple<char>> {
         .then_ignore(just("i64"))
         .map(|n| Token::Int64(n as i64));
 
+    let int_float = integer
+        .clone()
+        .then_ignore(just("_f"))
+        .map(|n| Token::IntFloat(n as i32));
+
     let int = integer.try_map(|n, span| {
         u32::try_from(n)
             .map(|n| Token::Int(n as i32))
-            .map_err(|err| Simple::custom(span, err.to_string()))
+            .map_err(|err| LexerError::custom(span, err.to_string()))
     });
 
-    let str_ = just('"')
+    let str_ = just('\\')
-        .ignore_then(filter(|c| *c != '"').repeated())
+        .then(any())
-        .then_ignore(just('"'))
+        .map(|t| vec![t.0, t.1])
-        .collect::<String>()
+        .or(none_of("\"").map(|c| vec![c]))
-        .map(Token::Str);
-
-    let op = one_of("+-*/%&^|<=>#")
         .repeated()
-        .at_least(1)
+        .flatten()
-        .or(just(':').chain(just('=')))
+        .delimited_by(just('"'), just('"'))
         .collect::<String>()
-        .map(Token::Op);
+        .map(|s| Token::Str(parse_string_escapes(s)));
+
+    let char_ = just('\\')
+        .then(any())
+        .map(|t| vec![t.0, t.1])
+        .or(none_of("\'").map(|c| vec![c]))
+        .repeated()
+        .flatten()
+        .delimited_by(just('\''), just('\''))
+        .collect::<String>()
+        .map(|s| {
+            let s = parse_string_escapes(s);
+            let mut value = 0;
+            for (i, c) in s.chars().enumerate() {
+                // TODO: generate error on overflow
+                if i < 4 {
+                    value |= (c as u32) << (i * 8);
+                }
+            }
+            Token::Int(value as i32)
+        });
+
+    let op = choice((
+        just("#/"),
+        just("#%"),
+        just("<<"),
+        just(">>"),
+        just("#>>"),
+        just(">="),
+        just("<="),
+        just("=="),
+        just("!="),
+        just("#>="),
+        just("#<="),
+        just("#<"),
+        just("#>"),
+        just("->"),
+        just(":="),
+        just("<|"),
+    ))
+    .map(|s| s.to_string())
+    .or(one_of("+-*/%&^|<=>").map(|s: char| s.to_string()))
+    .map(Token::Op)
+    .boxed();
 
     let ctrl = one_of("(){};,:?!$").map(Token::Ctrl);
 
-    fn ident() -> impl Parser<char, String, Error = Simple<char>> + Copy + Clone {
+    fn ident() -> impl Parser<char, String, Error = LexerError> + Copy + Clone {
         filter(|c: &char| c.is_ascii_alphabetic() || *c == '_')
             .map(Some)
             .chain::<char, Vec<_>, _>(
@@ -248,14 +377,9 @@ fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = Simple<char>> {
 
     let comment = single_line.or(multi_line);
 
-    let token = float
+    let token = choice((
-        .or(float64)
+        float, float64, int64, int_float, int, str_, char_, op, ctrl, ident,
-        .or(int64)
+    ))
-        .or(int)
-        .or(str_)
-        .or(op)
-        .or(ctrl)
-        .or(ident)
     .recover_with(skip_then_retry_until([]));
 
     token
@@ -263,44 +387,107 @@ fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = Simple<char>> {
         .padded()
         .padded_by(comment.padded().repeated())
         .repeated()
+        .boxed()
 }
 
 fn map_token<O>(
-    f: impl Fn(&Token) -> Option<O> + 'static + Clone,
+    f: impl Fn(&Token, &Span) -> Option<O> + 'static + Clone,
-) -> impl Parser<Token, O, Error = Simple<Token>> + Clone {
+) -> impl Parser<Token, O, Error = ScriptError> + Clone {
     filter_map(move |span, tok: Token| {
-        if let Some(output) = f(&tok) {
+        if let Some(output) = f(&tok, &span) {
             Ok(output)
         } else {
-            Err(Simple::expected_input_found(span, Vec::new(), Some(tok)))
+            Err(ScriptError::expected_input_found(
+                span,
+                Vec::new(),
+                Some(tok),
+            ))
         }
     })
 }
 
-fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + Clone {
+fn parse_string_escapes(s: String) -> String {
+    let mut result = String::new();
+    let mut chars = s.chars().peekable();
+    while let Some(c) = chars.next() {
+        if c != '\\' {
+            result.push(c);
+        } else if let Some(c) = chars.next() {
+            match c {
+                '0'..='9' | 'a'..='f' | 'A'..='F' => {
+                    let mut number = c.to_string();
+                    if let Some('0'..='9' | 'a'..='f' | 'A'..='F') = chars.peek() {
+                        number.push(chars.next().unwrap());
+                    }
+                    result.push(u8::from_str_radix(&number, 16).unwrap() as char);
+                }
+                'n' => result.push('\n'),
+                'r' => result.push('\r'),
+                't' => result.push('\t'),
+                other => result.push(other),
+            }
+        } else {
+            result.push('\\');
+        }
+    }
+    result
+}
+
+type ScriptError = Simple<Token, Span>;
+fn script_parser() -> impl Parser<Token, ast::Script, Error = ScriptError> + Clone {
     let identifier = filter_map(|span, tok| match tok {
         Token::Ident(id) => Ok(id),
-        _ => Err(Simple::expected_input_found(span, Vec::new(), Some(tok))),
+        _ => Err(ScriptError::expected_input_found(
+            span,
+            Vec::new(),
+            Some(tok),
+        )),
     })
     .labelled("identifier");
 
-    let integer = map_token(|tok| match tok {
+    let integer = map_token(|tok, _| match tok {
         Token::Int(v) => Some(*v),
         _ => None,
     });
 
-    let string = map_token(|tok| match tok {
+    let string = map_token(|tok, _| match tok {
         Token::Str(s) => Some(s.clone()),
         _ => None,
     });
 
+    let product_op = just(Token::Op("*".to_string()))
+        .to(ast::BinOp::Mul)
+        .or(just(Token::Op("/".to_string())).to(ast::BinOp::Div))
+        .or(just(Token::Op("#/".to_string())).to(ast::BinOp::DivU))
+        .or(just(Token::Op("%".to_string())).to(ast::BinOp::Rem))
+        .or(just(Token::Op("#%".to_string())).to(ast::BinOp::RemU))
+        .boxed();
+    let sum_op = just(Token::Op("+".to_string()))
+        .to(ast::BinOp::Add)
+        .or(just(Token::Op("-".to_string())).to(ast::BinOp::Sub))
+        .boxed();
+    let shift_op = just(Token::Op("<<".to_string()))
+        .to(ast::BinOp::Shl)
+        .or(just(Token::Op("#>>".to_string())).to(ast::BinOp::ShrU))
+        .or(just(Token::Op(">>".to_string())).to(ast::BinOp::ShrS))
+        .boxed();
+    let bit_op = just(Token::Op("&".to_string()))
+        .to(ast::BinOp::And)
+        .or(just(Token::Op("|".to_string())).to(ast::BinOp::Or))
+        .or(just(Token::Op("^".to_string())).to(ast::BinOp::Xor))
+        .boxed();
+
     let mut expression_out = None;
     let block = recursive(|block| {
         let mut block_expression = None;
         let expression = recursive(|expression| {
-            let val = map_token(|tok| match tok {
+            let val = map_token(|tok, span| match tok {
                 Token::Int(v) => Some(ast::Expr::I32Const(*v)),
                 Token::Int64(v) => Some(ast::Expr::I64Const(*v)),
+                Token::IntFloat(v) => Some(ast::Expr::Cast {
+                    value: Box::new(ast::Expr::I32Const(*v).with_span(span.clone())),
+                    type_: ast::Type::F32,
+                }),
                 Token::Float(v) => Some(ast::Expr::F32Const(v.parse().unwrap())),
                 Token::Float64(v) => Some(ast::Expr::F64Const(v.parse().unwrap())),
                 _ => None,
@@ -312,7 +499,11 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                     name: id,
                     local_id: None,
                 }),
-                _ => Err(Simple::expected_input_found(span, Vec::new(), Some(tok))),
+                _ => Err(ScriptError::expected_input_found(
+                    span,
+                    Vec::new(),
+                    Some(tok),
+                )),
             })
             .labelled("variable");
 
@@ -325,6 +516,36 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                 })
                 .boxed();
 
+            let local_tee_op = identifier
+                .then(
+                    product_op
+                        .clone()
+                        .or(sum_op.clone())
+                        .or(shift_op.clone())
+                        .or(bit_op.clone()),
+                )
+                .then_ignore(just(Token::Op(":=".to_string())))
+                .then(expression.clone())
+                .map_with_span(|((name, op), expr), span| ast::Expr::LocalTee {
+                    name: name.clone(),
+                    value: Box::new(
+                        ast::Expr::BinOp {
+                            left: Box::new(
+                                ast::Expr::Variable {
+                                    name,
+                                    local_id: None,
+                                }
+                                .with_span(span.clone()),
+                            ),
+                            right: Box::new(expr),
+                            op,
+                        }
+                        .with_span(span),
+                    ),
+                    local_id: None,
+                })
+                .boxed();
+
             let loop_expr = just(Token::Loop)
                 .ignore_then(identifier)
                 .then(block.clone())
@@ -341,14 +562,24 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                     block: Box::new(block),
                 });
 
-            let if_expr = just(Token::If)
+            let if_expr = recursive::<_, ast::Expr, _, _, _>(|if_expr| {
+                just(Token::If)
                     .ignore_then(expression.clone())
                     .then(block.clone())
-                .then(just(Token::Else).ignore_then(block.clone()).or_not())
+                    .then(
+                        just(Token::Else)
+                            .ignore_then(
+                                block
+                                    .clone()
+                                    .or(if_expr.map_with_span(|expr, span| expr.with_span(span))),
+                            )
+                            .or_not(),
+                    )
                     .map(|((condition, if_true), if_false)| ast::Expr::If {
                         condition: Box::new(condition),
                         if_true: Box::new(if_true),
                         if_false: if_false.map(Box::new),
+                    })
             });
 
             let block_expr = loop_expr.or(label_block_expr).or(if_expr).boxed();
@@ -392,16 +623,6 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                 })
                 .boxed();
 
-            let assign = identifier
-                .then_ignore(just(Token::Op("=".to_string())))
-                .then(expression.clone())
-                .map(|(name, value)| ast::Expr::Assign {
-                    name,
-                    value: Box::new(value),
-                    local_id: None,
-                })
-                .boxed();
-
             let select = just(Token::Select)
                 .ignore_then(
                     expression
@@ -435,17 +656,19 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                     value: value.map(Box::new),
                 });
 
-            let atom = val
+            let atom = choice((
-                .or(function_call)
+                val,
-                .or(assign)
+                function_call,
-                .or(local_tee)
+                local_tee,
-                .or(variable)
+                local_tee_op,
-                .or(block_expr)
+                variable,
-                .or(branch)
+                block_expr,
-                .or(branch_if)
+                branch,
-                .or(let_)
+                branch_if,
-                .or(select)
+                let_,
-                .or(return_)
+                select,
+                return_,
+            ))
             .map_with_span(|expr, span| expr.with_span(span))
             .or(expression
                 .clone()
@@ -467,7 +690,7 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                 .then(atom)
                 .map(|(ops, value)| {
                     ops.into_iter().rev().fold(value, |acc, (op, span)| {
-                        let span = span.start..acc.span.end;
+                        let span = (span.0, span.1.start..acc.span.1.end);
                         ast::Expr::UnaryOp {
                             op,
                             value: Box::new(acc),
@@ -507,7 +730,7 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                 poke_op: Option<((ast::MemSize, ast::Expression), ast::Expression)>,
             ) -> ast::Expression {
                 let left = peek_ops.into_iter().fold(left, |left, (size, right)| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::Peek(ast::MemoryLocation {
                         span: span.clone(),
                         left: Box::new(left),
@@ -517,7 +740,7 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                     .with_span(span)
                 });
                 if let Some(((size, right), value)) = poke_op {
-                    let span = left.span.start..value.span.end;
+                    let span = (left.span.0, left.span.1.start..value.span.1.end);
                     ast::Expr::Poke {
                         mem_location: ast::MemoryLocation {
                             span: span.clone(),
@@ -563,18 +786,9 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
 
             let op_product = memory_op
                 .clone()
-                .then(
+                .then(product_op.clone().then(memory_op.clone()).repeated())
-                    just(Token::Op("*".to_string()))
-                        .to(ast::BinOp::Mul)
-                        .or(just(Token::Op("/".to_string())).to(ast::BinOp::Div))
-                        .or(just(Token::Op("#/".to_string())).to(ast::BinOp::DivU))
-                        .or(just(Token::Op("%".to_string())).to(ast::BinOp::Rem))
-                        .or(just(Token::Op("#%".to_string())).to(ast::BinOp::RemU))
-                        .then(memory_op.clone())
-                        .repeated(),
-                )
                 .foldl(|left, (op, right)| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::BinOp {
                         op,
                         left: Box::new(left),
@@ -586,15 +800,9 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
 
             let op_sum = op_product
                 .clone()
-                .then(
+                .then(sum_op.clone().then(op_product.clone()).repeated())
-                    just(Token::Op("+".to_string()))
-                        .to(ast::BinOp::Add)
-                        .or(just(Token::Op("-".to_string())).to(ast::BinOp::Sub))
-                        .then(op_product.clone())
-                        .repeated(),
-                )
                 .foldl(|left, (op, right)| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::BinOp {
                         op,
                         left: Box::new(left),
@@ -606,16 +814,9 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
 
             let op_shift = op_sum
                 .clone()
-                .then(
+                .then(shift_op.clone().then(op_sum.clone()).repeated())
-                    just(Token::Op("<<".to_string()))
-                        .to(ast::BinOp::Shl)
-                        .or(just(Token::Op("#>>".to_string())).to(ast::BinOp::ShrU))
-                        .or(just(Token::Op(">>".to_string())).to(ast::BinOp::ShrS))
-                        .then(op_sum.clone())
-                        .repeated(),
-                )
                 .foldl(|left, (op, right)| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::BinOp {
                         op,
                         left: Box::new(left),
@@ -643,7 +844,7 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                         .repeated(),
                 )
                 .foldl(|left, (op, right)| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::BinOp {
                         op,
                         left: Box::new(left),
@@ -655,16 +856,9 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
 
             let op_bit = op_cmp
                 .clone()
-                .then(
+                .then(bit_op.clone().then(op_cmp.clone()).repeated())
-                    just(Token::Op("&".to_string()))
-                        .to(ast::BinOp::And)
-                        .or(just(Token::Op("|".to_string())).to(ast::BinOp::Or))
-                        .or(just(Token::Op("^".to_string())).to(ast::BinOp::Xor))
-                        .then(op_cmp.clone())
-                        .repeated(),
-                )
                 .foldl(|left, (op, right)| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::BinOp {
                         op,
                         left: Box::new(left),
@@ -682,7 +876,7 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
                         .repeated(),
                 )
                 .foldl(|left, right| {
-                    let span = left.span.start..right.span.end;
+                    let span = (left.span.0, left.span.1.start..right.span.1.end);
                     ast::Expr::First {
                         value: Box::new(left),
                         drop: Box::new(right),
@@ -696,11 +890,58 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
 
         let block_expression = block_expression.unwrap();
 
+        let assign = identifier
+            .then_ignore(just(Token::Op("=".to_string())))
+            .then(expression.clone())
+            .map(|(name, value)| ast::Expr::Assign {
+                name,
+                value: Box::new(value),
+                local_id: None,
+            })
+            .map_with_span(|expr, span| expr.with_span(span))
+            .boxed();
+
+        let assign_op = identifier
+            .then(
+                product_op
+                    .clone()
+                    .or(sum_op.clone())
+                    .or(shift_op.clone())
+                    .or(bit_op.clone()),
+            )
+            .then_ignore(just(Token::Op("=".to_string())))
+            .then(expression.clone())
+            .map_with_span(|((name, op), value), span| {
+                ast::Expr::Assign {
+                    name: name.clone(),
+                    value: Box::new(
+                        ast::Expr::BinOp {
+                            left: Box::new(
+                                ast::Expr::Variable {
+                                    name,
+                                    local_id: None,
+                                }
+                                .with_span(span.clone()),
+                            ),
+                            right: Box::new(value),
+                            op,
+                        }
+                        .with_span(span.clone()),
+                    ),
+                    local_id: None,
+                }
+                .with_span(span)
+            })
+            .boxed();
+
         block_expression
             .clone()
             .then(just(Token::Ctrl(';')).or_not())
             .map_with_span(|(expr, semi), span| (expr.with_span(span), semi.is_none()))
-            .or(expression.clone().then(just(Token::Ctrl(';')).to(false)))
+            .or(assign
+                .or(assign_op)
+                .or(expression.clone())
+                .then(just(Token::Ctrl(';')).to(false)))
             .repeated()
             .then(expression.clone().or_not())
             .map_with_span(|(mut statements, mut final_expression), span| {
@@ -830,6 +1071,21 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
             })
             .boxed();
 
+        let global_const = just(Token::Ident("const".to_string()))
+            .ignore_then(identifier)
+            .then(just(Token::Ctrl(':')).ignore_then(type_parser()).or_not())
+            .then(just(Token::Op("=".to_string())).ignore_then(expression.clone()))
+            .then_ignore(just(Token::Ctrl(';')))
+            .map_with_span(|((name, type_), value), span| {
+                ast::TopLevelItem::Const(ast::GlobalConst {
+                    name,
+                    type_,
+                    value,
+                    span,
+                })
+            })
+            .boxed();
+
         let data_i8 = just(Token::Ident("i8".to_string()))
             .to(ast::DataType::I8)
             .or(just(Token::Ident("i16".to_string())).to(ast::DataType::I16))
@@ -875,35 +1131,43 @@ fn script_parser() -> impl Parser<Token, ast::Script, Error = Simple<Token>> + C
             })
             .boxed();
 
-        import.or(function).or(global).or(data).boxed()
+        let include =
+            just(Token::Ident("include".to_string())).ignore_then(string.clone().map_with_span(
+                |path, span| ast::TopLevelItem::Include(ast::Include { span, path }),
+            ));
+
+        import
+            .or(function)
+            .or(global)
+            .or(data)
+            .or(include)
+            .or(global_const)
+            .boxed()
     };
 
     top_level_item.repeated().then_ignore(end()).map(|items| {
-        let mut script = ast::Script {
+        let mut script = ast::Script::default();
-            imports: Vec::new(),
-            global_vars: Vec::new(),
-            functions: Vec::new(),
-            data: Vec::new(),
-        };
         for item in items {
             match item {
                 ast::TopLevelItem::Import(i) => script.imports.push(i),
                 ast::TopLevelItem::GlobalVar(v) => script.global_vars.push(v),
                 ast::TopLevelItem::Function(f) => script.functions.push(f),
                 ast::TopLevelItem::Data(d) => script.data.push(d),
+                ast::TopLevelItem::Include(i) => script.includes.push(i),
+                ast::TopLevelItem::Const(c) => script.consts.push(c),
             }
         }
         script
     })
 }
 
-fn type_parser() -> impl Parser<Token, ast::Type, Error = Simple<Token>> + Clone {
+fn type_parser() -> impl Parser<Token, ast::Type, Error = ScriptError> + Clone {
     filter_map(|span, tok| match tok {
         Token::Ident(id) if id == "i32" => Ok(ast::Type::I32),
         Token::Ident(id) if id == "i64" => Ok(ast::Type::I64),
         Token::Ident(id) if id == "f32" => Ok(ast::Type::F32),
         Token::Ident(id) if id == "f64" => Ok(ast::Type::F64),
-        _ => Err(Simple::expected_input_found(
+        _ => Err(ScriptError::expected_input_found(
             span,
             vec![
                 Some(Token::Ident("i32".into())),

src/typecheck.rs

@@ -1,9 +1,9 @@
-use ariadne::{Color, Label, Report, ReportKind, Source};
+use ariadne::{Color, Label, Report, ReportKind};
 use std::collections::HashMap;
 
 use crate::ast::{self, MemSize};
 use crate::intrinsics::Intrinsics;
-use crate::Span;
+use crate::parser::{Sources, Span};
 use ast::Type::*;
 
 type Result<T> = std::result::Result<T, ()>;
@@ -15,9 +15,9 @@ struct Var {
 }
 type Vars = HashMap<String, Var>;
 
-pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
+pub fn tc_script(script: &mut ast::Script, sources: &Sources) -> Result<()> {
     let mut context = Context {
-        source,
+        sources,
         global_vars: HashMap::new(),
         functions: HashMap::new(),
         locals: ast::Locals::default(),
@@ -41,7 +41,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
                         "Global already defined",
                         &import.span,
                         span,
-                        source,
+                        sources,
                     );
                 } else {
                     context.global_vars.insert(
@@ -64,7 +64,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
                         "Function already defined",
                         &import.span,
                         &fnc.span,
-                        source,
+                        sources,
                     );
                 } else {
                     context.functions.insert(
@@ -83,12 +83,12 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
 
     for v in &mut script.global_vars {
         if let Some(Var { span, .. }) = context.global_vars.get(&v.name) {
-            result = report_duplicate_definition("Global already defined", &v.span, span, source);
+            result = report_duplicate_definition("Global already defined", &v.span, span, sources);
         } else {
-            tc_const(&mut v.value, source)?;
+            tc_const(&mut v.value, sources)?;
             if v.type_ != v.value.type_ {
                 if v.type_.is_some() {
-                    result = type_mismatch(v.type_, &v.span, v.value.type_, &v.value.span, source);
+                    result = type_mismatch(v.type_, &v.span, v.value.type_, &v.value.span, sources);
                 } else {
                     v.type_ = v.value.type_;
                 }
@@ -104,11 +104,26 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
         }
     }
 
+    for c in &mut script.consts {
+        tc_const(&mut c.value, sources)?;
+        if c.value.type_ != c.type_ {
+            if c.type_.is_some() {
+                result = type_mismatch(c.type_, &c.span, c.value.type_, &c.value.span, sources);
+            } else {
+                c.type_ = c.value.type_;
+            }
+        }
+    }
+
     for f in &script.functions {
         let params = f.params.iter().map(|(_, t)| *t).collect();
         if let Some(fnc) = context.functions.get(&f.name) {
-            result =
+            result = report_duplicate_definition(
-                report_duplicate_definition("Function already defined", &f.span, &fnc.span, source);
+                "Function already defined",
+                &f.span,
+                &fnc.span,
+                sources,
+            );
         } else {
             context.functions.insert(
                 f.name.clone(),
@@ -132,7 +147,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
                 .or_else(|| context.global_vars.get(name).map(|v| &v.span))
             {
                 result =
-                    report_duplicate_definition("Variable already defined", &f.span, span, source);
+                    report_duplicate_definition("Variable already defined", &f.span, span, sources);
             } else {
                 context.local_vars.insert(
                     name.clone(),
@@ -163,7 +178,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
         f.locals = std::mem::take(&mut context.locals);
 
         if f.body.type_ != f.type_ {
-            result = type_mismatch(f.type_, &f.span, f.body.type_, &f.body.span, source);
+            result = type_mismatch(f.type_, &f.span, f.body.type_, &f.body.span, sources);
         }
     }
 
@@ -171,7 +186,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
     for f in &script.functions {
         if f.start {
             if !f.params.is_empty() || f.type_.is_some() {
-                Report::build(ReportKind::Error, (), f.span.start)
+                Report::build(ReportKind::Error, f.span.0, f.span.1.start)
                     .with_message("Start function can't have params or a return value")
                     .with_label(
                         Label::new(f.span.clone())
@@ -179,7 +194,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
                             .with_color(Color::Red),
                     )
                     .finish()
-                    .eprint(Source::from(source))
+                    .eprint(sources)
                     .unwrap();
 
                 result = Err(());
@@ -189,7 +204,7 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
                     "Start function already defined",
                     &f.span,
                     &prev.span,
-                    source,
+                    sources,
                 );
             } else {
                 start_function = Some(f);
@@ -198,14 +213,14 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
     }
 
     for data in &mut script.data {
-        tc_const(&mut data.offset, source)?;
+        tc_const(&mut data.offset, sources)?;
         if data.offset.type_ != Some(I32) {
             result = type_mismatch(
                 Some(I32),
                 &data.offset.span,
                 data.offset.type_,
                 &data.offset.span,
-                source,
+                sources,
             );
         }
         for values in &mut data.data {
@@ -220,14 +235,14 @@ pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
                         ast::DataType::F64 => ast::Type::F64,
                     };
                     for value in values {
-                        tc_const(value, source)?;
+                        tc_const(value, sources)?;
                         if value.type_ != Some(needed_type) {
                             result = type_mismatch(
                                 Some(needed_type),
                                 &value.span,
                                 value.type_,
                                 &value.span,
-                                source,
+                                sources,
                             );
                         }
                     }
@@ -247,7 +262,7 @@ struct FunctionType {
 }
 
 struct Context<'a> {
-    source: &'a str,
+    sources: &'a Sources,
     global_vars: Vars,
     functions: HashMap<String, FunctionType>,
     locals: ast::Locals,
@@ -294,13 +309,13 @@ impl LocalVars {
     }
 }
 
-fn report_duplicate_definition(
+pub fn report_duplicate_definition(
     msg: &str,
     span: &Span,
     prev_span: &Span,
-    source: &str,
+    sources: &Sources,
 ) -> Result<()> {
-    Report::build(ReportKind::Error, (), span.start)
+    Report::build(ReportKind::Error, span.0, span.1.start)
         .with_message(msg)
         .with_label(
             Label::new(span.clone())
@@ -313,7 +328,7 @@ fn report_duplicate_definition(
                 .with_color(Color::Yellow),
         )
         .finish()
-        .eprint(Source::from(source))
+        .eprint(sources)
         .unwrap();
     Err(())
 }
@@ -323,9 +338,9 @@ fn type_mismatch(
     span1: &Span,
     type2: Option<ast::Type>,
     span2: &Span,
-    source: &str,
+    sources: &Sources,
 ) -> Result<()> {
-    Report::build(ReportKind::Error, (), span2.start)
+    Report::build(ReportKind::Error, span2.0, span2.1.start)
         .with_message("Type mismatch")
         .with_label(
             Label::new(span1.clone())
@@ -348,13 +363,13 @@ fn type_mismatch(
                 .with_color(Color::Red),
         )
         .finish()
-        .eprint(Source::from(source))
+        .eprint(sources)
         .unwrap();
     Err(())
 }
 
-fn report_error(msg: &str, span: &Span, source: &str) -> Result<()> {
+pub fn report_error(msg: &str, span: &Span, sources: &Sources) -> Result<()> {
-    Report::build(ReportKind::Error, (), span.start)
+    Report::build(ReportKind::Error, span.0, span.1.start)
         .with_message(msg)
         .with_label(
             Label::new(span.clone())
@@ -362,29 +377,29 @@ fn report_error(msg: &str, span: &Span, source: &str) -> Result<()> {
                 .with_color(Color::Red),
         )
         .finish()
-        .eprint(Source::from(source))
+        .eprint(sources)
         .unwrap();
     Err(())
 }
 
-fn expected_type(span: &Span, source: &str) -> Result<()> {
+fn expected_type(span: &Span, sources: &Sources) -> Result<()> {
     report_error(
         "Expected value but found expression of type void",
         span,
-        source,
+        sources,
     )
 }
 
-fn unknown_variable(span: &Span, source: &str) -> Result<()> {
+fn unknown_variable(span: &Span, sources: &Sources) -> Result<()> {
-    report_error("Unknown variable", span, source)
+    report_error("Unknown variable", span, sources)
 }
 
-fn immutable_assign(span: &Span, source: &str) -> Result<()> {
+fn immutable_assign(span: &Span, sources: &Sources) -> Result<()> {
-    report_error("Trying to assign to immutable variable", span, source)
+    report_error("Trying to assign to immutable variable", span, sources)
 }
 
-fn missing_label(span: &Span, source: &str) -> Result<()> {
+fn missing_label(span: &Span, sources: &Sources) -> Result<()> {
-    report_error("Label not found", span, source)
+    report_error("Label not found", span, sources)
 }
 
 fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()> {
@@ -423,11 +438,11 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                             &expr.span,
                             value.type_,
                             &value.span,
-                            context.source,
+                            context.sources,
                         );
                     }
                 } else if value.type_.is_none() {
-                    return expected_type(&value.span, context.source);
+                    return expected_type(&value.span, context.sources);
                 } else {
                     *type_ = value.type_;
                 }
@@ -449,7 +464,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                 *local_id = Some(id);
                 context.local_vars.insert(name.clone(), id);
             } else {
-                return report_error("Type missing", &expr.span, context.source);
+                return report_error("Type missing", &expr.span, context.sources);
             }
             None
         }
@@ -477,7 +492,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                     &expr.span,
                     value.type_,
                     &value.span,
-                    context.source,
+                    context.sources,
                 );
             }
             None
@@ -489,7 +504,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
         ast::Expr::UnaryOp { op, ref mut value } => {
             tc_expression(context, value)?;
             if value.type_.is_none() {
-                return expected_type(&value.span, context.source);
+                return expected_type(&value.span, context.sources);
             }
             use ast::Type::*;
             use ast::UnaryOp::*;
@@ -502,7 +517,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         &expr.span,
                         value.type_,
                         &value.span,
-                        context.source,
+                        context.sources,
                     )
                 }
             })
@@ -521,11 +536,11 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         &left.span,
                         right.type_,
                         &right.span,
-                        context.source,
+                        context.sources,
                     );
                 }
             } else {
-                return expected_type(&left.span, context.source);
+                return expected_type(&left.span, context.sources);
             }
             use ast::BinOp::*;
             match op {
@@ -537,7 +552,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                             &left.span,
                             left.type_,
                             &left.span,
-                            context.source,
+                            context.sources,
                         );
                     } else {
                         left.type_
@@ -551,7 +566,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                             &left.span,
                             left.type_,
                             &left.span,
-                            context.source,
+                            context.sources,
                         );
                     } else {
                         Some(I32)
@@ -569,7 +584,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
             } else if let Some(&Var { type_, .. }) = context.global_vars.get(name) {
                 Some(type_)
             } else {
-                return unknown_variable(&expr.span, context.source);
+                return unknown_variable(&expr.span, context.sources);
             }
         }
         ast::Expr::Assign {
@@ -583,7 +598,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                 *local_id = Some(id);
                 let local = &context.locals[id];
                 if local.index.is_none() {
-                    return immutable_assign(&expr.span, context.source);
+                    return immutable_assign(&expr.span, context.sources);
                 }
                 (local.type_, &local.span)
             } else if let Some(&Var {
@@ -593,15 +608,15 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
             }) = context.global_vars.get(name)
             {
                 if !mutable {
-                    return immutable_assign(&expr.span, context.source);
+                    return immutable_assign(&expr.span, context.sources);
                 }
                 (type_, span)
             } else {
-                return unknown_variable(&expr.span, context.source);
+                return unknown_variable(&expr.span, context.sources);
             };
 
             if value.type_ != Some(type_) {
-                return type_mismatch(Some(type_), span, value.type_, &value.span, context.source);
+                return type_mismatch(Some(type_), span, value.type_, &value.span, context.sources);
             }
             None
         }
@@ -616,7 +631,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                 let local = &context.locals[id];
 
                 if local.index.is_none() {
-                    return immutable_assign(&expr.span, context.source);
+                    return immutable_assign(&expr.span, context.sources);
                 }
 
                 if value.type_ != Some(local.type_) {
@@ -625,13 +640,13 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         &local.span,
                         value.type_,
                         &value.span,
-                        context.source,
+                        context.sources,
                     );
                 }
 
                 Some(local.type_)
             } else {
-                return unknown_variable(&expr.span, context.source);
+                return unknown_variable(&expr.span, context.sources);
             }
         }
         ast::Expr::Loop {
@@ -652,13 +667,13 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
             context.block_stack.pop();
             if block.type_ != None {
                 // TODO: implement, requires branches to optionally provide values
-                return type_mismatch(None, &expr.span, block.type_, &block.span, context.source);
+                return type_mismatch(None, &expr.span, block.type_, &block.span, context.sources);
             }
             None
         }
         ast::Expr::Branch(ref label) => {
             if !context.block_stack.contains(label) {
-                return missing_label(&expr.span, context.source);
+                return missing_label(&expr.span, context.sources);
             }
             None
         }
@@ -673,11 +688,11 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                     &expr.span,
                     condition.type_,
                     &condition.span,
-                    context.source,
+                    context.sources,
                 );
             }
             if !context.block_stack.contains(label) {
-                return missing_label(&expr.span, context.source);
+                return missing_label(&expr.span, context.sources);
             }
             None
         }
@@ -687,7 +702,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
         } => {
             tc_expression(context, value)?;
             if value.type_.is_none() {
-                return expected_type(&expr.span, context.source);
+                return expected_type(&expr.span, context.sources);
             }
             Some(type_)
         }
@@ -698,7 +713,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
             for param in params.iter_mut() {
                 tc_expression(context, param)?;
                 if param.type_.is_none() {
-                    return expected_type(&param.span, context.source);
+                    return expected_type(&param.span, context.sources);
                 }
             }
             if let Some(load) = context.intrinsics.find_load(name) {
@@ -713,11 +728,11 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                             &expr.span,
                             value.type_,
                             &value.span,
-                            context.source,
+                            context.sources,
                         )?;
                     }
                 } else {
-                    return report_error("Missing parameters", &expr.span, context.source);
+                    return report_error("Missing parameters", &expr.span, context.sources);
                 }
                 tc_memarg(context, &mut params[1..], &expr.span)?;
                 None
@@ -732,7 +747,8 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                 {
                     *rtype
                 } else {
-                    let mut report = Report::build(ReportKind::Error, (), expr.span.start)
+                    let mut report =
+                        Report::build(ReportKind::Error, expr.span.0, expr.span.1.start)
                             .with_message("No matching function found");
                     for (params, rtype) in type_map {
                         let param_str: Vec<_> = params.into_iter().map(|t| t.to_string()).collect();
@@ -748,17 +764,14 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         );
                         report = report.with_label(Label::new(expr.span.clone()).with_message(msg));
                     }
-                    report
+                    report.finish().eprint(context.sources).unwrap();
-                        .finish()
-                        .eprint(Source::from(context.source))
-                        .unwrap();
                     return Err(());
                 }
             } else {
                 return report_error(
                     &format!("Unknown function {}", name),
                     &expr.span,
-                    context.source,
+                    context.sources,
                 );
             }
         }
@@ -776,7 +789,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                     &condition.span,
                     condition.type_,
                     &condition.span,
-                    context.source,
+                    context.sources,
                 );
             }
             if if_true.type_.is_some() {
@@ -786,11 +799,11 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         &if_true.span,
                         if_false.type_,
                         &if_false.span,
-                        context.source,
+                        context.sources,
                     );
                 }
             } else {
-                return expected_type(&if_true.span, context.source);
+                return expected_type(&if_true.span, context.sources);
             }
             if_true.type_
         }
@@ -809,7 +822,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         &if_true.span,
                         if_false.type_,
                         &if_false.span,
-                        context.source,
+                        context.sources,
                     );
                 } else {
                     if_true.type_
@@ -827,7 +840,7 @@ fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()
                         &expr.span,
                         value.type_,
                         &value.span,
-                        context.source,
+                        context.sources,
                     );
                 }
             }
@@ -851,14 +864,14 @@ fn tc_mem_location<'a>(
     mem_location: &mut ast::MemoryLocation,
 ) -> Result<()> {
     tc_expression(context, &mut mem_location.left)?;
-    tc_const(&mut mem_location.right, context.source)?;
+    tc_const(&mut mem_location.right, context.sources)?;
     if mem_location.left.type_ != Some(I32) {
         return type_mismatch(
             Some(I32),
             &mem_location.left.span,
             mem_location.left.type_,
             &mem_location.left.span,
-            context.source,
+            context.sources,
         );
     }
     if mem_location.right.type_ != Some(I32) {
@@ -867,20 +880,20 @@ fn tc_mem_location<'a>(
             &mem_location.right.span,
             mem_location.right.type_,
             &mem_location.right.span,
-            context.source,
+            context.sources,
         );
     }
     Ok(())
 }
 
-fn tc_const(expr: &mut ast::Expression, source: &str) -> Result<()> {
+fn tc_const(expr: &mut ast::Expression, sources: &Sources) -> Result<()> {
     use ast::Expr::*;
     expr.type_ = Some(match expr.expr {
         I32Const(_) => I32,
         I64Const(_) => I64,
         F32Const(_) => F32,
         F64Const(_) => F64,
-        _ => return report_error("Expected constant value", &expr.span, source),
+        _ => return report_error("Expected constant value", &expr.span, sources),
     });
     Ok(())
 }
@@ -892,16 +905,16 @@ fn tc_memarg(context: &mut Context, params: &mut [ast::Expression], span: &Span)
         } else {
             "Too many MemArg parameters"
         };
-        return report_error(msg, span, context.source);
+        return report_error(msg, span, context.sources);
     }
 
     for (index, param) in params.iter_mut().enumerate() {
         tc_expression(context, param)?;
         if param.type_ != Some(I32) {
-            return type_mismatch(Some(I32), &span, param.type_, &param.span, context.source);
+            return type_mismatch(Some(I32), &span, param.type_, &param.span, context.sources);
         }
         if index > 0 {
-            tc_const(param, context.source)?;
+            tc_const(param, context.sources)?;
         }
         if index == 2 {
             let align = param.const_i32();
@@ -909,7 +922,7 @@ fn tc_memarg(context: &mut Context, params: &mut [ast::Expression], span: &Span)
                 return report_error(
                     &format!("Alignment {} out of range (0-4)", align),
                     &param.span,
-                    context.source,
+                    context.sources,
                 );
             }
         }

test/xorshift.cwa

@@ -0,0 +1,15 @@
+// simple test to see whether lazy/inline chains with the same variable compile correctly
+
+fn xorshift(x: i32) -> i32 {
+    let lazy x = x ^ (x << 13);
+    let lazy x = x ^ (x #>> 17);
+    let inline x = x ^ (x << 5);
+    x
+}
+
+fn xorshift2(x: i32) -> i32 {
+    x ^= x << 13;
+    x ^= x #>> 17;
+    x ^= x << 5;
+    x
+}