text/template/parse: undo breaking API changes

golang.org/cl/84480 altered the API for the parse package for
clarity and consistency. However, the changes also broke the
API for consumers of the package. This CL reverts the API
to the previous spelling, adding only a single new exported
symbol.

Fixes #25968

Change-Id: Ieb81054b61eeac7df3bc3864ef446df43c26b80f
Reviewed-on: https://go-review.googlesource.com/120355
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/src/text/template/exec.go b/src/text/template/exec.go
index 8f8b5fe218..214f72d51b 100644
--- a/src/text/template/exec.go
+++ b/src/text/template/exec.go
@@ -252,7 +252,7 @@ func (s *state) walk(dot reflect.Value, node parse.Node) {
 		// Do not pop variables so they persist until next end.
 		// Also, if the action declares variables, don't print the result.
 		val := s.evalPipeline(dot, node.Pipe)
-		if len(node.Pipe.Vars) == 0 {
+		if len(node.Pipe.Decl) == 0 {
 			s.printValue(node, val)
 		}
 	case *parse.IfNode:
@@ -339,11 +339,11 @@ func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) {
 	mark := s.mark()
 	oneIteration := func(index, elem reflect.Value) {
 		// Set top var (lexically the second if there are two) to the element.
-		if len(r.Pipe.Vars) > 0 {
+		if len(r.Pipe.Decl) > 0 {
 			s.setTopVar(1, elem)
 		}
 		// Set next var (lexically the first if there are two) to the index.
-		if len(r.Pipe.Vars) > 1 {
+		if len(r.Pipe.Decl) > 1 {
 			s.setTopVar(2, index)
 		}
 		s.walk(elem, r.List)
@@ -432,11 +432,11 @@ func (s *state) evalPipeline(dot reflect.Value, pipe *parse.PipeNode) (value ref
 			value = reflect.ValueOf(value.Interface()) // lovely!
 		}
 	}
-	for _, variable := range pipe.Vars {
-		if pipe.Decl {
-			s.push(variable.Ident[0], value)
-		} else {
+	for _, variable := range pipe.Decl {
+		if pipe.IsAssign {
 			s.setVar(variable.Ident[0], value)
+		} else {
+			s.push(variable.Ident[0], value)
 		}
 	}
 	return value
@@ -461,7 +461,7 @@ func (s *state) evalCommand(dot reflect.Value, cmd *parse.CommandNode, final ref
 	case *parse.PipeNode:
 		// Parenthesized pipeline. The arguments are all inside the pipeline; final is ignored.
 		return s.evalPipeline(dot, n)
-	case *parse.AssignNode:
+	case *parse.VariableNode:
 		return s.evalVariableNode(dot, n, cmd.Args, final)
 	}
 	s.at(firstWord)
@@ -530,7 +530,7 @@ func (s *state) evalChainNode(dot reflect.Value, chain *parse.ChainNode, args []
 	return s.evalFieldChain(dot, pipe, chain, chain.Field, args, final)
 }
 
-func (s *state) evalVariableNode(dot reflect.Value, variable *parse.AssignNode, args []parse.Node, final reflect.Value) reflect.Value {
+func (s *state) evalVariableNode(dot reflect.Value, variable *parse.VariableNode, args []parse.Node, final reflect.Value) reflect.Value {
 	// $x.Field has $x as the first ident, Field as the second. Eval the var, then the fields.
 	s.at(variable)
 	value := s.varValue(variable.Ident[0])
@@ -771,7 +771,7 @@ func (s *state) evalArg(dot reflect.Value, typ reflect.Type, n parse.Node) refle
 		s.errorf("cannot assign nil to %s", typ)
 	case *parse.FieldNode:
 		return s.validateType(s.evalFieldNode(dot, arg, []parse.Node{n}, missingVal), typ)
-	case *parse.AssignNode:
+	case *parse.VariableNode:
 		return s.validateType(s.evalVariableNode(dot, arg, nil, missingVal), typ)
 	case *parse.PipeNode:
 		return s.validateType(s.evalPipeline(dot, arg), typ)
@@ -889,7 +889,7 @@ func (s *state) evalEmptyInterface(dot reflect.Value, n parse.Node) reflect.Valu
 		return s.idealConstant(n)
 	case *parse.StringNode:
 		return reflect.ValueOf(n.Text)
-	case *parse.AssignNode:
+	case *parse.VariableNode:
 		return s.evalVariableNode(dot, n, nil, missingVal)
 	case *parse.PipeNode:
 		return s.evalPipeline(dot, n)