implement NoSemis and NoStringConcat mode for go/printer

R=rsc
https://golang.org/cl/174050

diff --git a/src/pkg/go/printer/nodes.go b/src/pkg/go/printer/nodes.go
index efb61a75cd6b044c61a8f1f056f13efdaced7f23..e5ecdd27893b74376490d2f81698855b9ece2d37 100644 (file)
--- a/src/pkg/go/printer/nodes.go
+++ b/src/pkg/go/printer/nodes.go
@@ -127,7 +127,11 @@ func (p *printer) stringList(list []*ast.BasicLit, multiLine *bool) {
        for i, x := range list {
                xlist[i] = x
        }
-       p.exprList(noPos, xlist, 1, stringListMode, multiLine);
+       mode := stringListMode;
+       if p.Mode&NoStringConcat != 0 {
+               mode |= plusSep
+       }
+       p.exprList(noPos, xlist, 1, mode, multiLine);
 }
 
 
@@ -136,6 +140,7 @@ type exprListMode uint
 const (
        blankStart      exprListMode    = 1 << iota;    // print a blank before a non-empty list
        blankEnd;                       // print a blank after a non-empty list
+       plusSep;                        // elements are separared by + operators
        commaSep;                       // elements are separated by commas
        commaTerm;                      // elements are terminated by comma
        noIndent;                       // no extra indentation in multi-line lists
@@ -165,6 +170,9 @@ func (p *printer) exprList(prev token.Position, list []ast.Expr, depth int, mode
                // all list entries on a single line
                for i, x := range list {
                        if i > 0 {
+                               if mode&plusSep != 0 {
+                                       p.print(blank, token.ADD)
+                               }
                                if mode&commaSep != 0 {
                                        p.print(token.COMMA)
                                }
@@ -197,6 +205,9 @@ func (p *printer) exprList(prev token.Position, list []ast.Expr, depth int, mode
                prev := line;
                line = x.Pos().Line;
                if i > 0 {
+                       if mode&plusSep != 0 {
+                               p.print(blank, token.ADD)
+                       }
                        if mode&commaSep != 0 {
                                p.print(token.COMMA)
                        }
@@ -374,7 +385,9 @@ func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace tok
                                p.expr(&ast.StringList{f.Tag}, &ml);
                                extraTabs = 0;
                        }
-                       p.print(token.SEMICOLON);
+                       if p.Mode&NoSemis == 0 {
+                               p.print(token.SEMICOLON)
+                       }
                        if f.Comment != nil {
                                for ; extraTabs > 0; extraTabs-- {
                                        p.print(vtab)
@@ -407,7 +420,9 @@ func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace tok
                                // embedded interface
                                p.expr(f.Type, &ml)
                        }
-                       p.print(token.SEMICOLON);
+                       if p.Mode&NoSemis == 0 {
+                               p.print(token.SEMICOLON)
+                       }
                        p.lineComment(f.Comment);
                }
                if isIncomplete {
@@ -818,7 +833,7 @@ func (p *printer) stmtList(list []ast.Stmt, _indent int) {
                // in those cases each clause is a new section
                p.linebreak(s.Pos().Line, 1, maxStmtNewlines, ignore, i == 0 || _indent == 0 || multiLine);
                multiLine = false;
-               if !p.stmt(s, &multiLine) && (!fewerSemis || len(list) > 1) {
+               if !p.stmt(s, &multiLine) && (!fewerSemis || len(list) > 1) && p.Mode&NoSemis == 0 {
                        p.print(token.SEMICOLON)
                }
        }
@@ -1144,7 +1159,7 @@ func (p *printer) spec(spec ast.Spec, n int, context declContext, multiLine *boo
                panic("unreachable")
        }
 
-       if context == inGroup || context == inStmtList && !optSemi {
+       if (context == inGroup || context == inStmtList && !optSemi) && p.Mode&NoSemis == 0 {
                p.print(token.SEMICOLON)
        }
 

diff --git a/src/pkg/go/printer/printer.go b/src/pkg/go/printer/printer.go
index a59dba32e25cc12c3f63b9ebc3a724a9a0d7608c..727b7afc9b4b0c460da470da353082724974682c 100644 (file)
--- a/src/pkg/go/printer/printer.go
+++ b/src/pkg/go/printer/printer.go
@@ -894,6 +894,8 @@ const (
        RawFormat;              // do not use a tabwriter; if set, UseSpaces is ignored
        TabIndent;              // use tabs for indentation independent of UseSpaces
        UseSpaces;              // use spaces instead of tabs for alignment
+       NoSemis;                // don't print semicolons at the end of a line
+       NoStringConcat;         // don't print string lists without "+"
 )