compiler: refactor typeinfo functions

pkg/compiler/types.go

@@ -0,0 +1,44 @@
+package compiler
+
+import (
+	"go/ast"
+	"go/types"
+)
+
+func (c *codegen) typeAndValueOf(e ast.Expr) types.TypeAndValue {
+	return c.typeInfo.Types[e]
+}
+
+func (c *codegen) typeOf(e ast.Expr) types.Type {
+	return c.typeAndValueOf(e).Type
+}
+
+func isBasicTypeOfKind(typ types.Type, ks ...types.BasicKind) bool {
+	if t, ok := typ.Underlying().(*types.Basic); ok {
+		k := t.Kind()
+		for i := range ks {
+			if k == ks[i] {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func isByte(typ types.Type) bool {
+	return isBasicTypeOfKind(typ, types.Uint8, types.Int8)
+}
+
+func isString(typ types.Type) bool {
+	return isBasicTypeOfKind(typ, types.String)
+}
+
+func isCompoundSlice(typ types.Type) bool {
+	t, ok := typ.Underlying().(*types.Slice)
+	return ok && !isByte(t.Elem())
+}
+
+func isByteSlice(typ types.Type) bool {
+	t, ok := typ.Underlying().(*types.Slice)
+	return ok && isByte(t.Elem())
+}