change datafmt syntax to use '@' instead of '^' (to match

convention used in template.go)

R=rsc
DELTA=22  (3 added, 1 deleted, 18 changed)
OCL=29780
CL=29782

src/lib/datafmt/datafmt.go

@@ -78,10 +78,10 @@
 
 	A field operand is a field name optionally followed by an alternate
 	rule name. The field name may be an identifier or one of the special
-	names ^ or *.
+	names @ or *.
 
 		Field       = FieldName [ ":" RuleName ] .
-		FieldName   = identifier | "^" | "*" .
+		FieldName   = identifier | "@" | "*" .
 
 	If the field name is an identifier, the current value must be a struct,
 	and there must be a field with that name in the struct. The same lookup
@@ -91,8 +91,7 @@
 	and an error message is returned. (TODO consider changing the semantics
 	such that if a field is not found, it evaluates to nil).
 
-	The special name '^' denotes the current value. (TODO see if ^ can
-	change to @ or be eliminated).
+	The special name '@' denotes the current value.
 
 	The meaning of the special name '*' depends on the type of the current
 	value:
@@ -252,7 +251,7 @@ type (
 	literal [][]byte;  // a list of string segments, possibly starting with '%'
 
 	field struct {
-		fieldName string;  // including "^", "*"
+		fieldName string;  // including "@", "*"
 		ruleName string;  // "" if no rule name specified
 	};
 
@@ -587,7 +586,7 @@ func (s *State) eval(fexpr expr, value reflect.Value, index int) bool {
 	case *field:
 		// determine field value
 		switch t.fieldName {
-		case "^":
+		case "@":
 			// field value is current value
 
 		case "*":

src/lib/datafmt/datafmt_test.go

@@ -76,10 +76,10 @@ func TestCustomFormatters(t *testing.T) {
 	f = parse(t, ``, fmap1);
 	verify(t, f, `even odd even odd `, 0, 1, 2, 3);
 
-	f = parse(t, `/ =^:blank; float="#"`, fmap1);
+	f = parse(t, `/ =@:blank; float="#"`, fmap1);
 	verify(t, f, `# # #`, 0.0, 1.0, 2.0);
 
-	f = parse(t, `float=^:nil`, fmap1);
+	f = parse(t, `float=@:nil`, fmap1);
 	verify(t, f, ``, 0.0, 1.0, 2.0);
 
 	// TODO needs more tests
@@ -212,7 +212,7 @@ func TestDefaultRule(t *testing.T) {
 	check(t, `default="%v"`, `42foo3.14`, 42, "foo", 3.14);
 	check(t, `default="%v"; int="%x"`, `abcdef`, 10, 11, 12, 13, 14, 15);
 	check(t, `default="%v"; int="%x"`, `ab**ef`, 10, 11, "**", 14, 15);
-	check(t, `default="%x"; int=^:default`, `abcdef`, 10, 11, 12, 13, 14, 15);
+	check(t, `default="%x"; int=@:default`, `abcdef`, 10, 11, 12, 13, 14, 15);
 }
 
 

src/lib/datafmt/parser.go

@@ -86,7 +86,7 @@ func (p *parser) next() {
 
 func (p *parser) init(src []byte) {
 	p.errors.Init(0);
-	p.scanner.Init(src, p, 0);
+	p.scanner.Init(src, p, scanner.AllowIllegalChars);  // return '@' as token.ILLEGAL w/o error message
 	p.next();  // initializes pos, tok, lit
 	p.packs = make(map [string] string);
 	p.rules = make(map [string] expr);
@@ -231,8 +231,11 @@ func (p *parser) parseLiteral() literal {
 func (p *parser) parseField() expr {
 	var fname string;
 	switch p.tok {
-	case token.XOR:
-		fname = "^";
+	case token.ILLEGAL:
+		if string(p.lit) != "@" {
+			return nil;
+		}
+		fname = "@";
 		p.next();
 	case token.MUL:
 		fname = "*";

usr/gri/pretty/ast.txt

@@ -44,7 +44,7 @@ ast.Decl =
 // Tokens and comments
 
 token.Token =
-	^:string;
+	@:string;
 
 ast.Comment =
 	// TODO this doesn't indent properly after //-style comments because
@@ -87,7 +87,7 @@ ast.StringList =
 	{Strings / "\n"};
 
 ast.FuncLit =
-	Type " " Body ^:clearOptSemi;  // no optional ; after a func literal body
+	Type " " Body @:clearOptSemi;  // no optional ; after a func literal body
 
 ast.CompositeLit =
 	Type "{" {Elts / ", "} "}";
@@ -139,7 +139,7 @@ funcSignature =
 	*:signature;
 
 ast.FuncType =
-	[Position:isValidPos "func"] ^:signature;
+	[Position:isValidPos "func"] @:signature;
 
 ast.InterfaceType =
 	"interface"
@@ -201,7 +201,7 @@ ast.BranchStmt =
 	Tok [" " Label];
 
 stmtList =
-	{^ / ^:optSemi "\n"};
+	{@ / @:optSemi "\n"};
 
 blockStmt =  // like ast.BlockStmt but w/o indentation
 	"{"
@@ -210,7 +210,7 @@ blockStmt =  // like ast.BlockStmt but w/o indentation
 		List:stmtList
 	"\n"
 	]
-	"}" ^:setOptSemi;
+	"}" @:setOptSemi;
 
 blockStmtPtr =
 	*:blockStmt;
@@ -222,7 +222,7 @@ ast.BlockStmt =
 		List:stmtList
 	) "\n"
 	]
-	"}" ^:setOptSemi;
+	"}" @:setOptSemi;
 
 ast.IfStmt =
 	"if " [Init "; "] [Cond " "] Body [" else " Else];
@@ -315,7 +315,7 @@ ast.GenDecl =
 			{Specs / ";\n"}
 		) "\n"
 		]
-		")" ^:setOptSemi
+		")" @:setOptSemi
 	|	{Specs / ";\n"}
 	);