add new features to readme

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:
@@ -138,6 +146,18 @@ 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:
@@ -296,15 +316,65 @@ 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
 

src/typecheck.rs

@@ -104,6 +104,17 @@ pub fn tc_script(script: &mut ast::Script, sources: &Sources) -> 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) {