text/template/parse: use human error prints

The previous version of all the node.String methods printed the parse
tree and was useful for developing the parse tree code. Now that that's done,
we might as well print the nodes using the standard template syntax.
It's much easier to read and makes error reporting look more natural.

Helps issue 2644.

R=rsc, n13m3y3r
CC=golang-dev
https://golang.org/cl/5553066

1 files changed, 27 insertions, 29 deletions

diff --git a/src/pkg/text/template/parse/parse_test.go b/src/pkg/text/template/parse/parse_test.go
index b70c2143d3..13c5548abb 100644
--- a/src/pkg/text/template/parse/parse_test.go
+++ b/src/pkg/text/template/parse/parse_test.go
@@ -150,7 +150,7 @@ type parseTest struct {
 	name   string
 	input  string
 	ok     bool
-	result string
+	result string // what the user would see in an error message.
 }
 
 const (
@@ -160,59 +160,57 @@ const (
 
 var parseTests = []parseTest{
 	{"empty", "", noError,
-		`[]`},
+		``},
 	{"comment", "{{/*\n\n\n*/}}", noError,
-		`[]`},
+		``},
 	{"spaces", " \t\n", noError,
-		`[(text: " \t\n")]`},
+		`" \t\n"`},
 	{"text", "some text", noError,
-		`[(text: "some text")]`},
+		`"some text"`},
 	{"emptyAction", "{{}}", hasError,
-		`[(action: [])]`},
+		`{{}}`},
 	{"field", "{{.X}}", noError,
-		`[(action: [(command: [F=[X]])])]`},
+		`{{.X}}`},
 	{"simple command", "{{printf}}", noError,
-		`[(action: [(command: [I=printf])])]`},
+		`{{printf}}`},
 	{"$ invocation", "{{$}}", noError,
-		"[(action: [(command: [V=[$]])])]"},
+		"{{$}}"},
 	{"variable invocation", "{{with $x := 3}}{{$x 23}}{{end}}", noError,
-		"[({{with [V=[$x]] := [(command: [N=3])]}} [(action: [(command: [V=[$x] N=23])])])]"},
+		"{{with $x := 3}}{{$x 23}}{{end}}"},
 	{"variable with fields", "{{$.I}}", noError,
-		"[(action: [(command: [V=[$ I]])])]"},
+		"{{$.I}}"},
 	{"multi-word command", "{{printf `%d` 23}}", noError,
-		"[(action: [(command: [I=printf S=`%d` N=23])])]"},
+		"{{printf `%d` 23}}"},
 	{"pipeline", "{{.X|.Y}}", noError,
-		`[(action: [(command: [F=[X]]) (command: [F=[Y]])])]`},
+		`{{.X | .Y}}`},
 	{"pipeline with decl", "{{$x := .X|.Y}}", noError,
-		`[(action: [V=[$x]] := [(command: [F=[X]]) (command: [F=[Y]])])]`},
-	{"declaration", "{{.X|.Y}}", noError,
-		`[(action: [(command: [F=[X]]) (command: [F=[Y]])])]`},
+		`{{$x := .X | .Y}}`},
 	{"simple if", "{{if .X}}hello{{end}}", noError,
-		`[({{if [(command: [F=[X]])]}} [(text: "hello")])]`},
+		`{{if .X}}"hello"{{end}}`},
 	{"if with else", "{{if .X}}true{{else}}false{{end}}", noError,
-		`[({{if [(command: [F=[X]])]}} [(text: "true")] {{else}} [(text: "false")])]`},
+		`{{if .X}}"true"{{else}}"false"{{end}}`},
 	{"simple range", "{{range .X}}hello{{end}}", noError,
-		`[({{range [(command: [F=[X]])]}} [(text: "hello")])]`},
+		`{{range .X}}"hello"{{end}}`},
 	{"chained field range", "{{range .X.Y.Z}}hello{{end}}", noError,
-		`[({{range [(command: [F=[X Y Z]])]}} [(text: "hello")])]`},
+		`{{range .X.Y.Z}}"hello"{{end}}`},
 	{"nested range", "{{range .X}}hello{{range .Y}}goodbye{{end}}{{end}}", noError,
-		`[({{range [(command: [F=[X]])]}} [(text: "hello")({{range [(command: [F=[Y]])]}} [(text: "goodbye")])])]`},
+		`{{range .X}}"hello"{{range .Y}}"goodbye"{{end}}{{end}}`},
 	{"range with else", "{{range .X}}true{{else}}false{{end}}", noError,
-		`[({{range [(command: [F=[X]])]}} [(text: "true")] {{else}} [(text: "false")])]`},
+		`{{range .X}}"true"{{else}}"false"{{end}}`},
 	{"range over pipeline", "{{range .X|.M}}true{{else}}false{{end}}", noError,
-		`[({{range [(command: [F=[X]]) (command: [F=[M]])]}} [(text: "true")] {{else}} [(text: "false")])]`},
+		`{{range .X | .M}}"true"{{else}}"false"{{end}}`},
 	{"range []int", "{{range .SI}}{{.}}{{end}}", noError,
-		`[({{range [(command: [F=[SI]])]}} [(action: [(command: [{{<.>}}])])])]`},
+		`{{range .SI}}{{.}}{{end}}`},
 	{"constants", "{{range .SI 1 -3.2i true false 'a'}}{{end}}", noError,
-		`[({{range [(command: [F=[SI] N=1 N=-3.2i B=true B=false N='a'])]}} [])]`},
+		`{{range .SI 1 -3.2i true false 'a'}}{{end}}`},
 	{"template", "{{template `x`}}", noError,
-		`[{{template "x"}}]`},
+		`{{template "x"}}`},
 	{"template with arg", "{{template `x` .Y}}", noError,
-		`[{{template "x" [(command: [F=[Y]])]}}]`},
+		`{{template "x" .Y}}`},
 	{"with", "{{with .X}}hello{{end}}", noError,
-		`[({{with [(command: [F=[X]])]}} [(text: "hello")])]`},
+		`{{with .X}}"hello"{{end}}`},
 	{"with with else", "{{with .X}}hello{{else}}goodbye{{end}}", noError,
-		`[({{with [(command: [F=[X]])]}} [(text: "hello")] {{else}} [(text: "goodbye")])]`},
+		`{{with .X}}"hello"{{else}}"goodbye"{{end}}`},
 	// Errors.
 	{"unclosed action", "hello{{range", hasError, ""},
 	{"unmatched end", "{{end}}", hasError, ""},