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- accept new semicolon syntax (at the moment,

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the parser accepts a bit more then it should)

R=r
OCL=16694
CL=16694
This commit is contained in:
Robert Griesemer 2008-10-07 17:57:19 -07:00
parent 38c2472609
commit 44dffd92fc
1 changed files with 51 additions and 40 deletions
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65
usr/gri/pretty/parser.go
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@ -15,12 +15,13 @@ export type Parser struct {
tokchan *<-chan *Scanner.Token;
// Scanner.Token
old int; // previous token
pos int; // token source position
tok int; // one token look-ahead
val string; // token value (for IDENT, NUMBER, STRING only)
// Nesting level
level int; // 0 = global scope, -1 = function/struct scope of global functions/structs, etc.
level int; // 0 = global scope, -1 = function scope of global functions, etc.
};
@ -53,6 +54,7 @@ func (P *Parser) Ecart() {
func (P *Parser) Next() {
P.old = P.tok;
if P.tokchan == nil {
P.pos, P.tok, P.val = P.scanner.Scan();
} else {
@ -71,6 +73,7 @@ func (P *Parser) Open(verbose bool, scanner *Scanner.Scanner, tokchan *<-chan *S
P.indent = 0;
P.scanner = scanner;
P.tokchan = tokchan;
P.old = Scanner.ILLEGAL;
P.Next();
P.level = 0;
}
@ -116,6 +119,18 @@ func (P *Parser) TryStatement() (stat AST.Stat, ok bool);
func (P *Parser) ParseDeclaration() AST.Node;
func (P *Parser) OptSemicolon(tok int) {
P.Trace("OptSemicolon");
if P.tok == Scanner.SEMICOLON {
P.Next();
} else if P.level != 0 || P.old != tok || P.tok != tok {
// TODO FIX THIS
// P.Expect(Scanner.SEMICOLON);
}
P.Ecart();
}
func (P *Parser) ParseIdent() *AST.Ident {
P.Trace("Ident");
@ -380,7 +395,6 @@ func (P *Parser) ParseMethodDecl() *AST.MethodDecl {
decl := new(AST.MethodDecl);
decl.ident = P.ParseIdent();
decl.typ = P.ParseFunctionType();
P.Optional(Scanner.SEMICOLON);
P.Ecart();
return decl;
@ -395,15 +409,17 @@ func (P *Parser) ParseInterfaceType() *AST.InterfaceType {
typ.methods = AST.NewList();
P.Expect(Scanner.INTERFACE);
P.Expect(Scanner.LBRACE);
P.OpenScope();
P.level--;
if P.tok == Scanner.LBRACE {
P.Next();
for P.tok == Scanner.IDENT {
typ.methods.Add(P.ParseMethodDecl());
if P.tok != Scanner.RBRACE {
P.Expect(Scanner.SEMICOLON);
}
}
P.level++;
P.CloseScope();
P.Expect(Scanner.RBRACE);
}
P.Ecart();
return typ;
@ -435,9 +451,9 @@ func (P *Parser) ParseStructType() *AST.StructType {
typ.fields = AST.NewList();
P.Expect(Scanner.STRUCT);
P.Expect(Scanner.LBRACE);
P.OpenScope();
P.level--;
if P.tok == Scanner.LBRACE {
P.Next();
for P.tok == Scanner.IDENT {
typ.fields.Add(P.ParseVarDeclList());
if P.tok != Scanner.RBRACE {
@ -445,9 +461,8 @@ func (P *Parser) ParseStructType() *AST.StructType {
}
}
P.Optional(Scanner.SEMICOLON);
P.level++;
P.CloseScope();
P.Expect(Scanner.RBRACE);
}
P.Ecart();
return typ;
@ -498,12 +513,14 @@ func (P *Parser) ParseStatement() AST.Stat {
P.Trace("Statement");
stat, ok := P.TryStatement();
if !ok {
if ok {
P.OptSemicolon(Scanner.RBRACE);
} else {
P.Error(P.pos, "statement expected");
P.Next(); // make progress
}
P.Ecart();
P.Ecart();
return stat;
}
@ -1326,10 +1343,7 @@ func (P *Parser) ParseDecl(exported bool, keyword int) *AST.Declaration {
P.Next();
for P.tok != Scanner.RPAREN {
decl.decls.Add(P.ParseSpec(exported, keyword));
if P.tok != Scanner.RPAREN {
// P.Expect(Scanner.SEMICOLON);
P.Optional(Scanner.SEMICOLON); // TODO this seems wrong! (needed for math.go)
}
P.OptSemicolon(Scanner.RPAREN);
}
P.Next(); // consume ")"
} else {
@ -1350,8 +1364,8 @@ func (P *Parser) ParseDecl(exported bool, keyword int) *AST.Declaration {
// func (recv) ident (params) type
// func (recv) ident (params) (results)
func (P *Parser) ParseFuncDecl(exported bool) *AST.FuncDecl {
P.Trace("FuncDecl");
func (P *Parser) ParseFunctionDecl(exported bool) *AST.FuncDecl {
P.Trace("FunctionDecl");
fun := new(AST.FuncDecl);
fun.pos = P.pos;
@ -1380,10 +1394,7 @@ func (P *Parser) ParseFuncDecl(exported bool) *AST.FuncDecl {
P.level++;
P.CloseScope();
if P.tok == Scanner.SEMICOLON {
// forward declaration
P.Next();
} else {
if P.tok == Scanner.LBRACE {
fun.body = P.ParseBlock();
}
@ -1437,7 +1448,7 @@ func (P *Parser) ParseDeclaration() AST.Node {
case Scanner.CONST, Scanner.TYPE, Scanner.VAR:
node = P.ParseDecl(exported, P.tok);
case Scanner.FUNC:
node = P.ParseFuncDecl(exported);
node = P.ParseFunctionDecl(exported);
case Scanner.EXPORT:
if exported {
P.Error(P.pos, "cannot mark export declaration for export");
@ -1453,6 +1464,8 @@ func (P *Parser) ParseDeclaration() AST.Node {
}
}
P.OptSemicolon(Scanner.RBRACE);
if indent != P.indent {
panic("imbalanced tracing code (Declaration)");
}
@ -1471,7 +1484,6 @@ func (P *Parser) ParseProgram() *AST.Program {
pos := P.pos;
P.Expect(Scanner.PACKAGE);
ident := P.ParseIdent();
P.Optional(Scanner.SEMICOLON);
decls := AST.NewList();
{ P.OpenScope();
@ -1486,7 +1498,6 @@ func (P *Parser) ParseProgram() *AST.Program {
for P.tok != Scanner.EOF {
decls.Add(P.ParseDeclaration());
P.Optional(Scanner.SEMICOLON);
}
if P.level != 0 {