daily snapshot:

- more work on template-driven ast formatting
- added preliminary test suite
- added documentation

TBR=r
OCL=27858
CL=27858

usr/gri/pretty/ast.txt

 //string =
-//	"%s" ;
+//	"%s";
 
 pointer =
-	^ ;
+	*;
 
 array =
-	^ ;
+	*;
 
 //token.Token =
-//	"token<%d>" ;  // this should be a Go-installed formatter
+//	"token<%d>";  // this could be a Go-installed formatter
 
 ast
 	;
 
 Comments =
-	"comments\n" ;
+	"comments\n";
 
 Ident =
-	Value ;
+	Value;
 
 Program =
-	"package " Name "\n\n" { Decls "\n\n" } ;
+	"package " Name "\n\n" {Decls "\n\n"};
 
 GenDecl =
 	Doc
@@ -28,13 +28,13 @@ GenDecl =
 	")\n";
 
 FuncType =
-	"(" { Params } ")" ;
+	"(" ")";
 
 BlockStmt =
-	"{\n" "}\n" ;
+	"{\n" "}\n";
 
 FuncDecl =
-	"func " Name Type [ " " Body ] ;
+	"func " Name Type [" " Body];
 	
 Decl =
-	^ ;
\ No newline at end of file
+	^;
\ No newline at end of file

usr/gri/pretty/format_test.go

+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package format
+
+import (
+	"format";
+	"testing";
+)
+
+
+func check(t *testing.T, form, expected string, args ...) {
+	result := format.Parse(form).Sprint(args);
+	if result != expected {
+		t.Errorf(
+			"format  : %s\nresult  : %s\nexpected: %s\n\n",
+			form, result, expected
+		)
+	}
+}
+
+
+// ----------------------------------------------------------------------------
+// - formatting of basic type int
+
+const F0 =
+	`int = "0x%x";`
+
+func Test0(t *testing.T) {
+	check(t, F0, "0x2a", 42);
+}
+
+
+// ----------------------------------------------------------------------------
+// - default formatting of basic type int
+// - formatting of a struct
+
+type T1 struct {
+	a int;
+}
+
+const F1 =
+	`format.T1 = "<" a ">";`
+
+func Test1(t *testing.T) {
+	check(t, F1, "<42>", T1{42});
+}
+
+
+// ----------------------------------------------------------------------------
+// - formatting of a struct with an optional field (pointer)
+// - default formatting for pointers
+
+type T2 struct {
+	s string;
+	p *T1;
+}
+
+const F2a =
+	F1 +
+	`pointer = *;`
+	`format.T2 = s ["-" p "-"];`;
+	
+const F2b =
+	F1 +
+	`format.T2 = s ("-" p "-" | "empty");`;
+	
+func Test2(t *testing.T) {
+	check(t, F2a, "foo", T2{"foo", nil});
+	check(t, F2a, "bar-<17>-", T2{"bar", &T1{17}});
+	check(t, F2b, "fooempty", T2{"foo", nil});
+}
+
+
+// ----------------------------------------------------------------------------
+// - formatting of a struct with a repetitive field (slice)
+
+type T3 struct {
+	s string;
+	a []int;
+}
+
+const F3a =
+	`format.T3 = s  { " " a a "," };`;
+
+const F3b =
+	`format.T3 = [a:""] s | "nothing";`;  // use 'a' to select alternative w/o printing a
+
+func Test3(t *testing.T) {
+	check(t, F3a, "foo", T3{"foo", nil});
+	check(t, F3a, "foo 00, 11, 22,", T3{"foo", []int{0, 1, 2}});
+	//check(t, F3b, "nothing", T3{"bar", nil});  // TODO fix this
+	check(t, F3b, "bar", T3{"bar", []int{0}});
+}

usr/gri/pretty/pretty.go

@@ -135,7 +135,7 @@ func main() {
 		if ok && !*silent {
 			tw := makeTabwriter(os.Stdout);
 			if *formatter {
-				ast_format.Apply(tw, prog);
+				ast_format.Fprint(tw, prog);
 			} else {
 				var p astPrinter.Printer;
 				p.Init(tw, nil, nil /*prog.Comments*/, false);