implement walkMutate(*node); completely transform AltIf->If

fixtures/0012-if-else.php

@@ -28,3 +28,11 @@ endif;
 
 // Unbraced
 if (true) echo "100";
+
+// Colon style within deeper scope
+
+{{{{
+	if (1 == 1):
+		echo "asdf";
+	endif;
+}}}}

main.go

@@ -48,8 +48,7 @@ func ConvertFile(filename string) (string, error) {
 	}
 
 	// Pass 1: Normalise Alt** Stmt types
-	normPass := normaliseAltsPass{}
-	n.Walk(&normPass) // can't modify root node, but that's fine
+	walkMutate(&n, normaliseAltCb)
 
 	// Debug pass: Walk and print JSON...
 	if fh, err := os.OpenFile(filename+`.parse2.json`, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err == nil {

mutatingwalker.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	//	"fmt"
+	//"io/ioutil"
+
+	"github.com/z7zmey/php-parser/node"
+	"github.com/z7zmey/php-parser/node/stmt"
+	//"github.com/z7zmey/php-parser/walker"
+)
+
+func walkMutate(n_ *node.Node, cb func(*node.Node)) {
+
+	// Mutate in-place, non recursive...
+	cb(n_)
+
+	// Walk on the mutated version
+	// We must reimplement .Walk() in order to get pointer behaviour
+
+	switch n := (*n_).(type) {
+	case *stmt.StmtList:
+		for i, _ := range n.Stmts {
+			walkMutate(&n.Stmts[i], cb)
+		}
+
+	case *node.Root:
+		for i, _ := range n.Stmts {
+			walkMutate(&n.Stmts[i], cb)
+		}
+
+	case *stmt.If:
+		walkMutate(&n.Cond, cb)
+		walkMutate(&n.Else, cb)
+		for i, _ := range n.ElseIf {
+			walkMutate(&n.ElseIf[i], cb)
+		}
+		walkMutate(&n.Stmt, cb)
+
+	case *stmt.Else:
+		walkMutate(&n.Stmt, cb)
+
+	case *stmt.ElseIf:
+		walkMutate(&n.Cond, cb)
+		walkMutate(&n.Stmt, cb)
+
+	default:
+		// FIXME need to implement Walk() for all node types, to ensure that
+		// we can perform mutation transforms in nested contexts
+		// bail
+		//panic(fmt.Sprintf("walkMutate: unimplemented type '%t'", n))
+
+	}
+
+}

normalisealts.go

@@ -1,101 +1,41 @@
 package main
 
 import (
-	"fmt"
+	//"fmt"
 	//"io/ioutil"
 
 	"github.com/z7zmey/php-parser/node"
 	"github.com/z7zmey/php-parser/node/stmt"
-	"github.com/z7zmey/php-parser/walker"
+	//"github.com/z7zmey/php-parser/walker"
 )
 
-type normaliseAltsPass struct {
-}
+func normaliseAltCb(n_ *node.Node) {
 
-func (np *normaliseAltsPass) transformNonRecursive(n node.Node) (node.Node, bool) {
-
-	switch n := n.(type) {
+	switch n := (*n_).(type) {
 	case *stmt.AltIf:
 		// Build replacement node
 		ifStmt := stmt.NewIf(n.Cond, n.Stmt, n.ElseIf, n.Else)
 		ifStmt.FreeFloating = n.FreeFloating
 		ifStmt.Position = n.Position
 		// ifStmt has no .Attributes prop
-		return ifStmt, true
+
+		*n_ = ifStmt
 
 	case *stmt.AltElse:
 		elseStmt := stmt.NewElse(n.Stmt)
 		elseStmt.FreeFloating = n.FreeFloating
 		elseStmt.Position = n.Position
-		return elseStmt, true
+
+		*n_ = elseStmt
 
 	case *stmt.AltElseIf:
 		elifStmt := stmt.NewElseIf(n.Cond, n.Stmt)
 		elifStmt.FreeFloating = n.FreeFloating
 		elifStmt.Position = n.Position
-		return elifStmt, true
+
+		*n_ = elifStmt
 
 	default:
-		return n, false // no change
+		return // no change
 	}
 }
-
-func (np *normaliseAltsPass) walkMutateArray(stmts []node.Node) {
-	for i, _ := range stmts {
-		np.walkMutate(&stmts[i])
-	}
-}
-
-func (np *normaliseAltsPass) walkMutate(child *node.Node) {
-
-	v2, didChange := np.transformNonRecursive(*child)
-	if didChange {
-		v2.Walk(np)
-		*child = v2
-	} else {
-		(*child).Walk(np)
-	}
-}
-
-func (np *normaliseAltsPass) EnterNode(w walker.Walkable) bool {
-	n, ok := w.(node.Node)
-	if !ok {
-		panic(fmt.Errorf("Tried to walk non-node '%t'", w))
-	}
-
-	// We need to override the .Walk() behaviour for all possible *parents*
-	// of affected nodes. This is because the .Walk() interface does not give
-	// us any opportunity to override single elements by the time we get there
-	// Our custom Walk() implementation is not firing all EnterChildList/LeaveNode
-	// visitors - but - that's fine since they're all noops anyway
-
-	switch n := n.(type) {
-	case *stmt.StmtList:
-		np.walkMutateArray(n.Stmts) // mutate slice in place
-		return false                // Signal not to use upstream .Walk() implementation
-
-	case *node.Root:
-		np.walkMutateArray(n.Stmts) // mutate slice in place
-		return false                // Signal not to use upstream .Walk() implementation
-
-	case *stmt.AltIf:
-		panic("altif")
-		np.walkMutate(&n.Cond)
-		np.walkMutateArray(n.ElseIf)
-		np.walkMutate(&n.Else)
-		return false
-
-	default:
-		// No normalisation needed for this node type
-		// Recurse deeper
-		return true
-	}
-}
-
-func (np *normaliseAltsPass) LeaveNode(w walker.Walkable)                  {}
-func (np *normaliseAltsPass) EnterChildNode(key string, w walker.Walkable) {}
-func (np *normaliseAltsPass) LeaveChildNode(key string, w walker.Walkable) {}
-func (np *normaliseAltsPass) EnterChildList(key string, w walker.Walkable) {}
-func (np *normaliseAltsPass) LeaveChildList(key string, w walker.Walkable) {}
-
-var _ walker.Visitor = &normaliseAltsPass{} // interface assertion