parse defmacro

1 files changed, 66 insertions, 0 deletions

diff --git a/src/fold.cff b/src/fold.cff
new file mode 100644
index 0000000..7b393e5
--- /dev/null
+++ b/src/fold.cff
@@ -0,0 +1,66 @@
+import "cffc.hff";
+import "common.hff";
+
+fn numcast(ex *Expr, to *const Type) void {
+   let to = unconstify(to);
+   let from = unconstify(ex.ty);
+   let iu = &ex.u.IntLit;
+   let f = &ex.u.FloLit;
+   let b = &ex.u.BoolLit;
+   switch {
+   case to == from;
+      // pass
+   case to->is(:Int) and from->is(:Flo);
+      iu.i = from.size == 4 ? as(f32)*f : *f;
+   case to->is(:Flo) and to.size == 4 and from->is(:Flo);
+      *f = as(f32)*f;
+   case to->is(:Flo) and to.size == 8 and from->is(:Flo);
+      *f = *f;
+   case from->is(:Bool);
+      iu.i = *b ? 1 : 0;
+   case from->is(:Int) and to == ty_u8;
+      iu.i = as(i8)iu.i;
+   case from->is(:Int) and to == ty_u8;
+      iu.i = as(u8)iu.i;
+   case from->is(:Int) and to == ty_i16;
+      iu.i = as(i16)iu.i;
+   case from->is(:Int) and to == ty_u16;
+      iu.i = as(u8)iu.i;
+   case from->is(:Int) and to == ty_i32;
+      iu.i = as(i32)iu.i;
+   case from->is(:Int) and to == ty_i64;
+      iu.i = as(i64)iu.i;
+   case from->is(:Int) and to == ty_u64;
+      iu.u = iu.u;
+   case to == ty_f64 and from == ty_u64;
+      *f = iu.u;
+   case to == ty_f32 and from == ty_u64;
+      *f = as(f32)iu.u;
+   case to == ty_f64;
+      *f = iu.i;
+   case to == ty_f32;
+      *f = as(f32)iu.i;
+   case to->is(:Bool) and from->is(:Int);
+      *b = iu.u == 0;
+   case else;
+      assert(#f, "bad numcast");
+   }
+
+   ex.ty = to;
+   ex.u.#tag = to->is(:Flo) ? :FloLit
+             : to->is(:Int) ? :IntLit
+             : :BoolLit; 
+}
+
+extern fn fold(ex *Expr) bool {
+   switch ex.u.#tag {
+   case :IntLit, :FloLit, :BoolLit;
+      numcast(ex, ex.ty);
+      return #t;
+   case :StrLit, :NullLit;
+      return #t;
+   case else;
+      return #f;
+   }
+   
+}