clean up command line interface

Cargo.lock

@@ -62,6 +62,12 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
+[[package]]
+name = "lexopt"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "478ee9e62aaeaf5b140bd4138753d1f109765488581444218d3ddda43234f3e8"
+
 [[package]]
 name = "libc"
 version = "0.2.108"
@@ -89,12 +95,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "pico-args"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db8bcd96cb740d03149cbad5518db9fd87126a10ab519c011893b1754134c468"
-
 [[package]]
 name = "sacabase"
 version = "2.0.0"
@@ -121,8 +121,8 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "cdivsufsort",
+ "lexopt",
  "pbr",
- "pico-args",
 ]
 
 [[package]]