Parse hex literals

Author: binji

ml-proto/src/host/lexer.mll

@@ -97,7 +97,8 @@ let escape = ['n''t''\\''\'''\"']
 let character = [^'"''\\''\n'] | '\\'escape | '\\'hexdigit hexdigit
 
 let num = ('+' | '-')? digit+
-let int = num
+let hexnum = ('+' | '-')? "0x" digit+
+let int = num | hexnum
 let float = (num '.' digit+) | num ('.' digit+)? ('e' | 'E') num
 let text = '"' character* '"'
 let name = '$' (letter | digit | '_' | tick | symbol)+

ml-proto/test/hexnum.wasm

@@ -0,0 +1,9 @@
+(module
+  (func $f (result i32)
+    (return (i32.const 0x12345678))
+  )
+
+  (export "f" $f)
+)
+
+(assert_eq (invoke "f") (i32.const 305419896))