From: Robert Findley <rfindley@google.com>
Date: Tue, 16 Nov 2021 03:27:19 +0000 (-0500)
Subject: go/types: move some functions into different files (cleanup)
X-Git-Tag: go1.18beta1~298
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=50dac3b410b9bc47dabc3f3c2afd21f7aecfb118;p=gostls13.git

go/types: move some functions into different files (cleanup)

This is a clean port of CL 362995 from types2 to go/types.

Change-Id: Iefc37b28178795ea944e0bc0ff91982251de2944
Reviewed-on: https://go-review.googlesource.com/c/go/+/363989
Trust: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
---

diff --git a/src/go/types/builtins.go b/src/go/types/builtins.go
index 8d293a9af3..9b50403d7f 100644
--- a/src/go/types/builtins.go
+++ b/src/go/types/builtins.go
@@ -776,46 +776,6 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	return true
 }
 
-// If typ is a type parameter, structuralType returns the single underlying
-// type of all types in the corresponding type constraint if it exists, or
-// nil otherwise. If typ is not a type parameter, structuralType returns
-// the underlying type.
-func structuralType(typ Type) Type {
-	var su Type
-	if underIs(typ, func(u Type) bool {
-		if su != nil && !Identical(su, u) {
-			return false
-		}
-		// su == nil || Identical(su, u)
-		su = u
-		return true
-	}) {
-		return su
-	}
-	return nil
-}
-
-// structuralString is like structuralType but also considers []byte
-// and string as "identical". In this case, if successful, the result
-// is always []byte.
-func structuralString(typ Type) Type {
-	var su Type
-	if underIs(typ, func(u Type) bool {
-		if isString(u) {
-			u = NewSlice(universeByte)
-		}
-		if su != nil && !Identical(su, u) {
-			return false
-		}
-		// su == nil || Identical(su, u)
-		su = u
-		return true
-	}) {
-		return su
-	}
-	return nil
-}
-
 // hasVarSize reports if the size of type t is variable due to type parameters.
 func hasVarSize(t Type) bool {
 	switch t := under(t).(type) {
diff --git a/src/go/types/type.go b/src/go/types/type.go
index b1e2bda4cd..26a605444d 100644
--- a/src/go/types/type.go
+++ b/src/go/types/type.go
@@ -27,10 +27,47 @@ func under(t Type) Type {
 	return t
 }
 
-// If the argument to asNamed, or asTypeParam is of the respective type
-// (possibly after resolving a *Named type), these methods return that type.
-// Otherwise the result is nil.
+// If typ is a type parameter, structuralType returns the single underlying
+// type of all types in the corresponding type constraint if it exists,
+// or nil otherwise. If typ is not a type parameter, structuralType returns
+// the underlying type.
+func structuralType(typ Type) Type {
+	var su Type
+	if underIs(typ, func(u Type) bool {
+		if su != nil && !Identical(su, u) {
+			return false
+		}
+		// su == nil || Identical(su, u)
+		su = u
+		return true
+	}) {
+		return su
+	}
+	return nil
+}
+
+// structuralString is like structuralType but also considers []byte
+// and string as "identical". In this case, if successful, the result
+// is always []byte.
+func structuralString(typ Type) Type {
+	var su Type
+	if underIs(typ, func(u Type) bool {
+		if isString(u) {
+			u = NewSlice(universeByte)
+		}
+		if su != nil && !Identical(su, u) {
+			return false
+		}
+		// su == nil || Identical(su, u)
+		su = u
+		return true
+	}) {
+		return su
+	}
+	return nil
+}
 
+// If t is a defined type, asNamed returns that type (possibly after resolving it), otherwise it returns nil.
 func asNamed(t Type) *Named {
 	e, _ := t.(*Named)
 	if e != nil {
@@ -39,6 +76,7 @@ func asNamed(t Type) *Named {
 	return e
 }
 
+// If t is a type parameter, asTypeParam returns that type, otherwise it returns nil.
 func asTypeParam(t Type) *TypeParam {
 	u, _ := under(t).(*TypeParam)
 	return u