1 files changed, 68 insertions, 0 deletions
diff --git a/src/types.lisp b/src/types.lisp
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+(defpackage #:sarcasm.types
+  (:use #:cl)
+  (:export
+   #:i32 #:i64 #:f32 #:f64
+   #:numtype
+   #:typeidx
+   #:vectype
+   #:funcref
+   #:externref
+   #:reftype
+   #:valtype
+   #:stacksig))
+
+(in-package #:sarcasm.types)
+
+(deftype i32 ()
+  '(integer 0 #.(expt 2 32)))
+
+(deftype i64 ()
+  '(integer 0 #. (expt 2 64)))
+
+(deftype f32 ()
+  'single-float)
+
+(deftype f64 ()
+  'double-float)
+
+(deftype numtype ()
+  '(or i32 i64 f32 f64))
+
+(deftype typeidx ()
+  'i32)
+
+(deftype vectype ()
+  '(bit-vector 128))
+
+(deftype funcref ()
+  't)
+
+(deftype externref ()
+  't)
+
+(deftype reftype ()
+  '(or funcref externref))
+
+(deftype valtype ()
+  '(or numtype vectype reftype))
+
+(defun stacksig-p (thing)
+  "A stack effect type is a two element list of lists of keywords.
+
+It describes the types of values consumed off the stack and returned
+to the stack by instructions."
+  (and (listp thing)
+       (= 2 (length thing))
+       (listp (first thing))
+       (listp (second thing))
+       (every #'keywordp (first thing))
+       (every #'keywordp (second thing))))
+
+(deftype stacksig ()
+  "This is not part of the standard grammar, but appears implicitly in
+the WASM table of instructions found
+
+ https://webassembly.github.io/spec/core/appendix/index-instructions.html
+
+In the `Type` column."
+  '(satisfies stack-effect-type-p))