Merge pull request #7726 from planetscale/rewriter-closure

making fast AST rewriter faster

go/tools/asthelpergen/integration/integration_rewriter_test.go

@@ -34,8 +34,7 @@ func TestRewriteVisitRefContainer(t *testing.T) {
 
  tv := &rewriteTestVisitor{}
 
- _, err := Rewrite(containerContainer, tv.pre, tv.post)
- require.NoError(t, err)
+ _ = Rewrite(containerContainer, tv.pre, tv.post)
 
  expected := []step{
  Pre{containerContainer},
@@ -58,8 +57,7 @@ func TestRewriteVisitValueContainer(t *testing.T) {
 
  tv := &rewriteTestVisitor{}
 
- _, err := Rewrite(containerContainer, tv.pre, tv.post)
- require.NoError(t, err)
+ _ = Rewrite(containerContainer, tv.pre, tv.post)
 
  expected := []step{
  Pre{containerContainer},
@@ -84,8 +82,7 @@ func TestRewriteVisitRefSliceContainer(t *testing.T) {
 
  tv := &rewriteTestVisitor{}
 
- _, err := Rewrite(containerContainer, tv.pre, tv.post)
- require.NoError(t, err)
+ _ = Rewrite(containerContainer, tv.pre, tv.post)
 
  tv.assertEquals(t, []step{
  Pre{containerContainer},
@@ -113,8 +110,7 @@ func TestRewriteVisitValueSliceContainer(t *testing.T) {
 
  tv := &rewriteTestVisitor{}
 
- _, err := Rewrite(containerContainer, tv.pre, tv.post)
- require.NoError(t, err)
+ _ = Rewrite(containerContainer, tv.pre, tv.post)
 
  tv.assertEquals(t, []step{
  Pre{containerContainer},
@@ -150,8 +146,7 @@ func TestRewriteVisitInterfaceSlice(t *testing.T) {
 
  tv := &rewriteTestVisitor{}
 
- _, err := Rewrite(ast, tv.pre, tv.post)
- require.NoError(t, err)
+ _ = Rewrite(ast, tv.pre, tv.post)
 
  tv.assertEquals(t, []step{
  Pre{ast},
@@ -176,22 +171,20 @@ func TestRewriteVisitRefContainerReplace(t *testing.T) {
  }
 
  // rewrite field of type AST
- _, err := Rewrite(ast, func(cursor *Cursor) bool {
+ _ = Rewrite(ast, func(cursor *Cursor) bool {
  leaf, ok := cursor.node.(*RefContainer)
  if ok && leaf.NotASTType == 12 {
  cursor.Replace(&Leaf{99})
  }
  return true
  }, nil)
- require.NoError(t, err)
 
  assert.Equal(t, &RefContainer{
  ASTType: &Leaf{99},
  ASTImplementationType: &Leaf{2},
  }, ast)
 
- _, err = Rewrite(ast, rewriteLeaf(2, 55), nil)
- require.NoError(t, err)
+ _ = Rewrite(ast, rewriteLeaf(2, 55), nil)
 
  assert.Equal(t, &RefContainer{
  ASTType: &Leaf{99},
@@ -200,20 +193,25 @@ func TestRewriteVisitRefContainerReplace(t *testing.T) {
 }
 
 func TestRewriteVisitValueContainerReplace(t *testing.T) {
+
  ast := ValueContainer{
  ASTType: ValueContainer{NotASTType: 12},
  ASTImplementationType: &Leaf{2},
  }
 
- _, err := Rewrite(ast, func(cursor *Cursor) bool {
+ defer func() {
+ if r := recover(); r != nil {
+ require.Equal(t, "[BUG] tried to replace 'ASTType' on 'ValueContainer'", r)
+ }
+ }()
+ _ = Rewrite(ast, func(cursor *Cursor) bool {
  leaf, ok := cursor.node.(ValueContainer)
  if ok && leaf.NotASTType == 12 {
  cursor.Replace(&Leaf{99})
  }
  return true
  }, nil)
 
- require.Error(t, err)
 }
 
 func TestRewriteVisitValueContainerReplace2(t *testing.T) {
@@ -222,8 +220,12 @@ func TestRewriteVisitValueContainerReplace2(t *testing.T) {
  ASTImplementationType: &Leaf{2},
  }
 
- _, err := Rewrite(ast, rewriteLeaf(2, 10), nil)
- require.Error(t, err)
+ defer func() {
+ if r := recover(); r != nil {
+ require.Equal(t, "[BUG] tried to replace 'ASTImplementationType' on 'ValueContainer'", r)
+ }
+ }()
+ _ = Rewrite(ast, rewriteLeaf(2, 10), nil)
 }
 
 func TestRewriteVisitRefContainerPreOrPostOnly(t *testing.T) {
@@ -234,8 +236,7 @@ func TestRewriteVisitRefContainerPreOrPostOnly(t *testing.T) {
 
  tv := &rewriteTestVisitor{}
 
- _, err := Rewrite(containerContainer, tv.pre, nil)
- require.NoError(t, err)
+ _ = Rewrite(containerContainer, tv.pre, nil)
  tv.assertEquals(t, []step{
  Pre{containerContainer},
  Pre{container},
@@ -244,8 +245,7 @@ func TestRewriteVisitRefContainerPreOrPostOnly(t *testing.T) {
  })
 
  tv = &rewriteTestVisitor{}
- _, err = Rewrite(containerContainer, nil, tv.post)
- require.NoError(t, err)
+ _ = Rewrite(containerContainer, nil, tv.post)
  tv.assertEquals(t, []step{
  Post{leaf1},
  Post{leaf2},
@@ -270,16 +270,14 @@ func TestRefSliceContainerReplace(t *testing.T) {
  ASTImplementationElements: []*Leaf{{3}, {4}},
  }
 
- _, err := Rewrite(ast, rewriteLeaf(2, 42), nil)
- require.NoError(t, err)
+ _ = Rewrite(ast, rewriteLeaf(2, 42), nil)
 
  assert.Equal(t, &RefSliceContainer{
  ASTElements: []AST{&Leaf{1}, &Leaf{42}},
  ASTImplementationElements: []*Leaf{{3}, {4}},
  }, ast)
 
- _, err = Rewrite(ast, rewriteLeaf(3, 88), nil)
- require.NoError(t, err)
+ _ = Rewrite(ast, rewriteLeaf(3, 88), nil)
 
  assert.Equal(t, &RefSliceContainer{
  ASTElements: []AST{&Leaf{1}, &Leaf{42}},

go/tools/asthelpergen/integration/test_helpers.go

@@ -39,8 +39,10 @@ func sliceStringLeaf(els ...*Leaf) string {
 
 // the methods below are what the generated code expected to be there in the package
 
+// ApplyFunc is apply function
 type ApplyFunc func(*Cursor) bool
 
+// Cursor is cursor
 type Cursor struct {
  parent AST
  replacer replacerFunc
@@ -62,20 +64,18 @@ func (c *Cursor) Replace(newNode AST) {
 
 type replacerFunc func(newNode, parent AST)
 
-func Rewrite(node AST, pre, post ApplyFunc) (AST, error) {
+// Rewrite is the api.
+func Rewrite(node AST, pre, post ApplyFunc) AST {
  outer := &struct{ AST }{node}
 
  a := &application{
  pre: pre,
  post: post,
  }
 
- err := a.rewriteAST(outer, node, func(newNode, parent AST) {
+ a.rewriteAST(outer, node, func(newNode, parent AST) {
  outer.AST = newNode
  })
 
- if err != nil {
- return nil, err
- }
- return outer.AST, nil
+ return outer.AST
 }

go/tools/asthelpergen/integration/types.go

@@ -174,8 +174,6 @@ func (r *NoCloneType) String() string {
 
 type Visit func(node AST) (bool, error)
 
-var errAbort = fmt.Errorf("this error is to abort the rewriter, it is not an actual error")
-
 type application struct {
  pre, post ApplyFunc
  cur Cursor