snapshot:

- fallthrough stat, label decls
- improved printing layout

R=r
OCL=17283
CL=17283

diff --git a/usr/gri/pretty/parser.go b/usr/gri/pretty/parser.go
index a4b4d56854f4699747a3647bee64c2f42aa71e78..f195a8e73da6d6b539750ce0c5ebc1d1e6a06990 100644 (file)
--- a/usr/gri/pretty/parser.go
+++ b/usr/gri/pretty/parser.go
@@ -786,6 +786,8 @@ func (P *Parser) ParseSimpleStat() *Node.Stat {
        case Scanner.COLON:
                // label declaration
                if x.len() == 1 {
+                       s = Node.NewStat(P.pos, Scanner.COLON);
+                       s.expr = x;
                } else {
                        P.Error(P.pos, "illegal label declaration");
                }
@@ -810,7 +812,7 @@ func (P *Parser) ParseSimpleStat() *Node.Stat {
                        } else {
                                P.Error(P.pos, "more then one operand");
                        }
-                       P.Next();
+                       P.Next();  // consume "++" or "--"
                } else {
                        s = Node.NewStat(P.pos, 0);  // TODO give this a token value
                        if x.len() == 1 {
@@ -857,7 +859,7 @@ func (P *Parser) ParseControlFlowStat(tok int) *Node.Stat {
        
        s := Node.NewStat(P.pos, tok);
        P.Expect(tok);
-       if P.tok == Scanner.IDENT {
+       if tok != Scanner.FALLTHROUGH && P.tok == Scanner.IDENT {
                s.expr = P.ParseIdent();
        }
        
@@ -911,7 +913,16 @@ func (P *Parser) ParseIfStat() *Node.Stat {
                if P.tok == Scanner.IF {
                        s.post = P.ParseIfStat();
                } else {
-                       s.post = P.ParseStatement();
+                       // For 6g compliance - should really be P.ParseBlock()
+                       t := P.ParseStatement();
+                       if t.tok != Scanner.LBRACE {
+                               // wrap in a block if we don't have one
+                               t1 := Node.NewStat(P.pos, Scanner.LBRACE);
+                               t1.block = Node.NewList();
+                               t1.block.Add(t);
+                               t = t1;
+                       }
+                       s.post = t;
                }
        }
        
@@ -1031,17 +1042,6 @@ func (P *Parser) ParseSelectStat() *Node.Stat {
 }
 
 
-func (P *Parser) ParseFallthroughStat() *Node.Stat {
-       P.Trace("FallthroughStat");
-       
-       s := Node.NewStat(P.pos, Scanner.FALLTHROUGH);
-       P.Expect(Scanner.FALLTHROUGH);
-
-       P.Ecart();
-       return s;
-}
-
-
 func (P *Parser) ParseRangeStat() *Node.Stat {
        P.Trace("RangeStat");
        
@@ -1073,7 +1073,8 @@ func (P *Parser) ParseStatement() *Node.Stat {
                s = Node.NewStat(P.pos, P.tok);
                s.decl = P.ParseDeclaration();
        case Scanner.FUNC:
-               // for now we do not allow local function declarations
+               // for now we do not allow local function declarations,
+               // instead we assume this starts a function literal
                fallthrough;
        case
                // only the tokens that are legal top-level expression starts
@@ -1085,7 +1086,7 @@ func (P *Parser) ParseStatement() *Node.Stat {
                s = P.ParseGoStat();
        case Scanner.RETURN:
                s = P.ParseReturnStat();
-       case Scanner.BREAK, Scanner.CONTINUE, Scanner.GOTO:
+       case Scanner.BREAK, Scanner.CONTINUE, Scanner.GOTO, Scanner.FALLTHROUGH:
                s = P.ParseControlFlowStat(P.tok);
        case Scanner.LBRACE:
                s = Node.NewStat(P.pos, Scanner.LBRACE);
@@ -1100,8 +1101,6 @@ func (P *Parser) ParseStatement() *Node.Stat {
                s = P.ParseRangeStat();
        case Scanner.SELECT:
                s = P.ParseSelectStat();
-       case Scanner.FALLTHROUGH:
-               s = P.ParseFallthroughStat();
        default:
                P.ParseEmptyStat();  // for complete tracing output only
        }

diff --git a/usr/gri/pretty/printer.go b/usr/gri/pretty/printer.go
index 2b5e70da1734ec86d323e72a8e6ba20b3365aacb..2156ae7e7d02d3421b82420d309ea2769e8de04b 100644 (file)
--- a/usr/gri/pretty/printer.go
+++ b/usr/gri/pretty/printer.go
@@ -12,7 +12,7 @@ export type Printer struct {
        level int;  // true scope level
        indent int;  // indentation level
        semi bool;  // pending ";"
-       newl bool;  // pending "\n"
+       newl int;  // pending "\n"'s
 }
 
 
@@ -20,14 +20,19 @@ func (P *Printer) String(pos int, s string) {
        if P.semi && P.level > 0 {  // no semicolons at level 0
                print(";");
        }
-       if P.newl {
-               print("\n");
+       
+       if P.newl > 0 {
+               for i := P.newl; i > 0; i-- {
+                       print("\n");
+               }
                for i := P.indent; i > 0; i-- {
                        print("\t");
                }
        }
+
        print(s);
-       P.newl, P.semi = false, false;
+
+       P.semi, P.newl = false, 0;
 }
 
 
@@ -41,18 +46,12 @@ func (P *Printer) Token(pos int, tok int) {
 }
 
 
-func (P *Printer) NewLine() {  // explicit "\n"
-       print("\n");
-       P.semi, P.newl = false, true;
-}
-
-
 func (P *Printer) OpenScope(paren string) {
-       P.semi, P.newl = false, false;
+       P.semi, P.newl = false, 0;
        P.String(0, paren);
        P.level++;
        P.indent++;
-       P.newl = true;
+       P.newl = 1;
 }
 
 
@@ -61,7 +60,7 @@ func (P *Printer) CloseScope(paren string) {
        P.semi = false;
        P.String(0, paren);
        P.level--;
-       P.semi, P.newl = false, true;
+       P.semi, P.newl = false, 1;
 }
 
 
@@ -95,7 +94,7 @@ func (P *Printer) Fields(list *Node.List) {
                if i > 0 {
                        if prev == Scanner.TYPE {
                                P.String(0, ";");
-                               P.newl = true;
+                               P.newl = 1;
                        } else if prev == x.tok {
                                P.String(0, ", ");
                        } else {
@@ -105,7 +104,7 @@ func (P *Printer) Fields(list *Node.List) {
                P.Expr(x);
                prev = x.tok;
        }
-       P.newl = true;
+       P.newl = 1;
 }
 
 
@@ -261,7 +260,7 @@ func (P *Printer) Stat(s *Node.Stat)
 func (P *Printer) StatementList(list *Node.List) {
        for i, n := 0, list.len(); i < n; i++ {
                P.Stat(list.at(i).(*Node.Stat));
-               P.newl = true;
+               P.newl = 1;
        }
 }
 
@@ -310,16 +309,27 @@ func (P *Printer) Stat(s *Node.Stat) {
 
        switch s.tok {
        case 0: // TODO use a real token const
+               // expression statement
                P.Expr(s.expr);
                P.semi = true;
 
+       case Scanner.COLON:
+               // label declaration
+               P.indent--;
+               P.Expr(s.expr);
+               P.Token(s.pos, s.tok);
+               P.indent++;
+               P.semi = false;
+               
        case Scanner.CONST, Scanner.TYPE, Scanner.VAR:
+               // declaration
                P.Declaration(s.decl, false);
 
        case Scanner.DEFINE, Scanner.ASSIGN, Scanner.ADD_ASSIGN,
                Scanner.SUB_ASSIGN, Scanner.MUL_ASSIGN, Scanner.QUO_ASSIGN,
                Scanner.REM_ASSIGN, Scanner.AND_ASSIGN, Scanner.OR_ASSIGN,
                Scanner.XOR_ASSIGN, Scanner.SHL_ASSIGN, Scanner.SHR_ASSIGN:
+               // assignment
                P.Expr(s.lhs);
                P.Blank();
                P.Token(s.pos, s.tok);
@@ -333,6 +343,7 @@ func (P *Printer) Stat(s *Node.Stat) {
                P.semi = true;
 
        case Scanner.LBRACE:
+               // block
                P.Block(s.block, true);
 
        case Scanner.IF:
@@ -340,7 +351,7 @@ func (P *Printer) Stat(s *Node.Stat) {
                P.ControlClause(s);
                P.Block(s.block, true);
                if s.post != nil {
-                       P.newl = false;
+                       P.newl = 0;
                        P.String(0, " else ");
                        P.Stat(s.post);
                }
@@ -366,10 +377,12 @@ func (P *Printer) Stat(s *Node.Stat) {
                P.StatementList(s.block);
                P.CloseScope("");
 
-       case Scanner.GO, Scanner.RETURN, Scanner.BREAK, Scanner.CONTINUE, Scanner.GOTO:
+       case Scanner.GO, Scanner.RETURN, Scanner.FALLTHROUGH, Scanner.BREAK, Scanner.CONTINUE, Scanner.GOTO:
                P.Token(s.pos, s.tok);
-               P.Blank();
-               P.Expr(s.expr);
+               if s.expr != nil {
+                       P.Blank();
+                       P.Expr(s.expr);
+               }
                P.semi = true;
 
        default:
@@ -430,16 +443,18 @@ func (P *Printer) Declaration(d *Node.Decl, parenthesized bool) {
                P.OpenScope("(");
                for i := 0; i < d.list.len(); i++ {
                        P.Declaration(d.list.at(i).(*Node.Decl), true);
-                       P.newl, P.semi = true, true;
+                       P.semi, P.newl = true, 1;
                }
                P.CloseScope(")");
 
        } else {
                P.Expr(d.ident);
+               
                if d.typ != nil {
                        P.Blank();
                        P.Type(d.typ);
                }
+
                if d.val != nil {
                        if d.tok == Scanner.IMPORT {
                                P.Blank();
@@ -448,6 +463,7 @@ func (P *Printer) Declaration(d *Node.Decl, parenthesized bool) {
                        }
                        P.Expr(d.val);
                }
+
                if d.list != nil {
                        if d.tok != Scanner.FUNC {
                                panic("must be a func declaration");
@@ -456,13 +472,18 @@ func (P *Printer) Declaration(d *Node.Decl, parenthesized bool) {
                        P.Block(d.list, true);
                }
        }
+       
+       P.newl = 1;
 
+       // extra newline after a function declaration
+       if d.tok == Scanner.FUNC {
+               P.newl++;
+       }
+       
        // extra newline at the top level
        if P.level == 0 {
-               P.NewLine();
+               P.newl++;
        }
-
-       P.newl = true;
 }
 
 
@@ -472,10 +493,10 @@ func (P *Printer) Declaration(d *Node.Decl, parenthesized bool) {
 func (P *Printer) Program(p *Node.Program) {
        P.String(p.pos, "package ");
        P.Expr(p.ident);
-       P.NewLine();
+       P.newl = 2;
        for i := 0; i < p.decls.len(); i++ {
                P.Declaration(p.decls.at(i), false);
        }
-       P.newl = true;
+       P.newl = 1;
        P.String(0, "");  // flush
 }