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Commit df7efaf9 authored by Robert Griesemer's avatar Robert Griesemer
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- improved comment intersperse heuristic: 

  comments should now be indented properly in corner cases
  (at the end of statement lists, for instance)

- changed import decl. formatting as suggested by Russ (no "global"
  indentation of imports if there are renames present)

- better field list handling

- better documentation

R=rsc
DELTA=534  (324 added, 35 deleted, 175 changed)
OCL=35557
CL=35630
parent e2854875
Show whitespace changes
Inline Side-by-side
Showing with 480 additions and 191 deletions
src/pkg/go/printer/printer.go
View file @ df7efaf9
......@@ -39,14 +39,18 @@ const (
type whiteSpace int
const (
ignore = whiteSpace(0);
blank = whiteSpace(' ');
vtab = whiteSpace('\v');
newline = whiteSpace('\n');
formfeed = whiteSpace('\f');
indent = whiteSpace('>');
unindent = whiteSpace('<');
)
var (
htab = []byte{'\t'};
htabs = [...]byte{'\t', '\t', '\t', '\t', '\t', '\t', '\t', '\t'};
newlines = [...]byte{'\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n'}; // more than maxNewlines
ampersand = strings.Bytes("&amp;");
......@@ -69,25 +73,34 @@ type htmlTag struct {
type printer struct {
// configuration (does not change after initialization)
// Configuration (does not change after initialization)
output io.Writer;
mode uint;
errors chan os.Error;
// current state (changes during printing)
// Current state
written int; // number of bytes written
indent int; // current indentation
last token.Position; // (possibly estimated) position immediately after the last item; in AST space
pos token.Position; // (possibly estimated) position; in AST space
// Buffered whitespace
buffer []whiteSpace;
// The (possibly estimated) position in the generated output;
// in AST space (i.e., pos is set whenever a token position is
// known accurately, and updated dependending on what has been
// written)
pos token.Position;
// The value of pos immediately after the last item has been
// written using writeItem.
last token.Position;
// HTML support
tag htmlTag; // tag to be used around next item
lastTaggedLine int; // last line for which a line tag was written
// buffered whitespace
buffer [8]whiteSpace; // whitespace sequences are short (1 or 2); 8 entries is plenty
buflen int;
// comments
comment *ast.CommentGroup; // list of comments; or nil
// The list of comments; or nil.
comment *ast.CommentGroup;
}
......@@ -95,6 +108,7 @@ func (p *printer) init(output io.Writer, mode uint) {
p.output = output;
p.mode = mode;
p.errors = make(chan os.Error);
p.buffer = make([]whiteSpace, 0, 16); // whitespace sequences are short
}
......@@ -118,34 +132,39 @@ const (
)
// write interprets data and writes it to p.output. It inserts indentation
// after newline or formfeed and HTML-escapes characters if GenHTML is set.
// after newline or formfeed if not in writeRaw mode and HTML-escapes characters
// if GenHTML is set. It updates p.pos as a side-effect.
//
func (p *printer) write(data []byte, mode writeMode) {
i0 := 0;
for i, b := range data {
switch b {
case '\n', '\f':
if mode & writeRaw == 0 {
// write segment ending in b followed by indentation
// write segment ending in b
p.write0(data[i0 : i+1]);
// update p.pos
p.pos.Offset += i+1 - i0;
p.pos.Line++;
p.pos.Column = 1;
if mode & writeRaw == 0 {
// write indentation
// use horizontal ("hard") tabs - indentation columns
// use "hard" htabs - indentation columns
// must not be discarded by the tabwriter
j := p.indent;
for ; j > len(htabs); j -= len(htabs) {
p.write0(&htabs);
}
p.write0(htabs[0 : j]);
p.write0(htabs[0:j]);
// update p.pos
p.pos.Offset += i+1 - i0 + p.indent;
p.pos.Line++;
p.pos.Column = p.indent + 1;
p.pos.Offset += p.indent;
p.pos.Column += p.indent;
}
// next segment start
i0 = i+1;
}
case '&', '<', '>':
if p.mode & GenHTML != 0 {
......@@ -162,8 +181,9 @@ func (p *printer) write(data []byte, mode writeMode) {
p.write0(esc);
// update p.pos
p.pos.Offset += i+1 - i0;
p.pos.Column += i+1 - i0;
d := i+1 - i0;
p.pos.Offset += d;
p.pos.Column += d;
// next segment start
i0 = i+1;
......@@ -175,9 +195,9 @@ func (p *printer) write(data []byte, mode writeMode) {
p.write0(data[i0 : len(data)]);
// update p.pos
n := len(data) - i0;
p.pos.Offset += n;
p.pos.Column += n;
d := len(data) - i0;
p.pos.Offset += d;
p.pos.Column += d;
}
......@@ -191,6 +211,13 @@ func (p *printer) writeNewlines(n int) {
}
// writeItem writes data at position pos. data is the text corresponding to
// a single lexical token, but may also be comment text. pos is the actual
// (or at least very accurately estimated) position of the data in the original
// source text. The data may be tagged, depending on p.mode and the mode
// parameter. writeItem updates p.last to the position immediately following
// the data.
//
func (p *printer) writeItem(pos token.Position, data []byte, mode writeMode) {
p.pos = pos;
if debug {
......@@ -226,10 +253,81 @@ func (p *printer) writeItem(pos token.Position, data []byte, mode writeMode) {
}
// TODO(gri): decide if this is needed - keep around for now
/*
// Reduce contiguous sequences of '\t' in a []byte to a single '\t'.
func untabify(src []byte) []byte {
// writeCommentPrefix writes the whitespace before a comment.
// If there is any pending whitespace, it consumes as much of
// it as is likely to help the comment position properly.
// line is the comment line, isFirst indicates if this is the
// first comment in a group of comments.
//
func (p *printer) writeCommentPrefix(line int, isFirst bool) {
if !p.last.IsValid() {
// there was no preceeding item and the comment is the
// first item to be printed - don't write any whitespace
return;
}
n := line - p.last.Line;
if n == 0 {
// comment on the same line as last item:
// separate with at least one tab
hasTab := false;
if isFirst {
j := 0;
for i, ch := range p.buffer {
switch ch {
case blank:
// ignore any blanks before a comment
p.buffer[i] = ignore;
continue;
case vtab:
// respect existing tabs - important
// for proper formatting of commented structs
hasTab = true;
continue;
case indent:
// apply pending indentation
continue;
}
j = i;
break;
}
p.writeWhitespace(j);
}
// make sure there is at least one tab
if !hasTab {
p.write(htab, 0);
}
} else {
// comment on a different line:
// separate with at least one line break
if isFirst {
j := 0;
for i, ch := range p.buffer {
switch ch {
case blank, vtab:
// ignore any horizontal whitespace before line breaks
p.buffer[i] = ignore;
continue;
case indent:
// apply pending indentation
continue;
case newline, formfeed:
// TODO(gri): may want to keep formfeed info in some cases
p.buffer[i] = ignore;
}
j = i;
break;
}
p.writeWhitespace(j);
}
p.writeNewlines(n);
}
}
// Collapse contiguous sequences of '\t' in a []byte to a single '\t'.
func collapseTabs(src []byte) []byte {
dst := make([]byte, len(src));
j := 0;
for i, c := range src {
......@@ -240,98 +338,128 @@ func untabify(src []byte) []byte {
}
return dst[0 : j];
}
*/
func (p *printer) writeComment(comment *ast.Comment) {
// separation from last item
if p.last.IsValid() {
// there was a preceding item (otherwise, the comment is the
// first item to be printed - in that case do not apply extra
// spacing)
n := comment.Pos().Line - p.last.Line;
if n == 0 {
// comment on the same line as last item; separate with tab
p.write(htabs[0 : 1], 0);
} else {
// comment on a different line; separate with newlines
p.writeNewlines(n);
}
// If there are tabs in the comment text, they were probably introduced
// to align the comment contents. If the same tab settings were used as
// by the printer, reducing tab sequences to single tabs will yield the
// original comment again after reformatting via the tabwriter.
text := comment.Text;
if p.mode & RawFormat == 0 {
// tabwriter is used
text = collapseTabs(comment.Text);
}
// write comment
p.writeItem(comment.Pos(), comment.Text, 0);
p.writeItem(comment.Pos(), text, 0);
}
func (p *printer) intersperseComments(next token.Position) {
firstLine := 0;
needsNewline := false;
for ; p.comment != nil && p.comment.List[0].Pos().Offset < next.Offset; p.comment = p.comment.Next {
for _, c := range p.comment.List {
if firstLine == 0 {
firstLine = c.Pos().Line;
// writeCommentSuffix writes a line break after a comment if indicated
// and processes any leftover indentation information. If a line break
// is needed, the kind of break (newline vs formfeed) depends on the
// pending whitespace.
//
func (p *printer) writeCommentSuffix(needsLinebreak bool) {
for i, ch := range p.buffer {
switch ch {
case blank, vtab:
// ignore trailing whitespace
p.buffer[i] = ignore;
case indent, unindent:
// don't loose indentation information
case newline, formfeed:
// if we need a line break, keep exactly one
if needsLinebreak {
needsLinebreak = false;
} else {
p.buffer[i] = ignore;
}
p.writeComment(c);
needsNewline = c.Text[1] == '/';
}
}
p.writeWhitespace(len(p.buffer));
// Eliminate non-newline whitespace from whitespace buffer.
j := 0;
for i := 0; i < p.buflen; i++ {
ch := p.buffer[i];
if ch == '\n' || ch == '\f' {
p.buffer[j] = ch;
j++;
}
// make sure we have a line break
if needsLinebreak {
p.write([]byte{'\n'}, 0);
}
p.buflen = j;
}
// Eliminate extra newlines from whitespace buffer if they
// are not present in the original source. This makes sure
// that comments that need to be adjacent to a declaration
// remain adjacent.
if p.last.IsValid() {
n := next.Line - p.last.Line;
if n < p.buflen {
p.buflen = n;
}
}
// If the whitespace buffer is not empty, it contains only
// newline or formfeed chars. Force a formfeed char if the
// comments span more than one line - in this case the
// structure of the next line is likely to change. Otherwise
// use the existing char, if any.
if needsNewline {
ch := p.buffer[0]; // existing char takes precedence
if p.buflen == 0 {
p.buflen = 1;
ch = newline; // original ch was a lie
}
if p.last.Line > firstLine {
ch = formfeed; // comments span at least 2 lines
// intersperseComments consumes all comments that appear before the next token
// and prints it together with the buffered whitespace (i.e., the whitespace
// that needs to be written before the next token). A heuristic is used to mix
// the comments and whitespace.
//
func (p *printer) intersperseComments(next token.Position) {
isFirst := true;
needsLinebreak := false;
for ; p.commentBefore(next); p.comment = p.comment.Next {
for _, c := range p.comment.List {
p.writeCommentPrefix(c.Pos().Line, isFirst);
isFirst = false;
p.writeComment(c);
needsLinebreak = c.Text[1] == '/';
}
p.buffer[0] = ch;
}
p.writeCommentSuffix(needsLinebreak);
}
func (p *printer) writeWhitespace() {
var a [len(p.buffer)]byte;
for i := 0; i < p.buflen; i++ {
a[i] = byte(p.buffer[i]);
// whiteWhitespace writes the first n whitespace entries.
func (p *printer) writeWhitespace(n int) {
// write entries
var data [1]byte;
for i := 0; i < n; i++ {
switch ch := p.buffer[i]; ch {
case ignore:
// ignore!
case indent:
p.indent++;
case unindent:
p.indent--;
if p.indent < 0 {
// handle gracefully unless in debug mode
if debug {
panicln("negative indentation:", p.indent);
}
p.indent = 0;
}
case newline, formfeed:
// A line break immediately followed by a "correcting"
// unindent is swapped with the unindent - this permits
// proper label positioning. If a comment is between
// the line break and the label, the unindent is not
// part of the comment whitespace prefix and the comment
// will be positioned correctly indented.
if i+1 < n && p.buffer[i+1] == unindent {
p.buffer[i], p.buffer[i+1] = unindent, ch;
i--; // do it again
continue;
}
fallthrough;
default:
data[0] = byte(ch);
p.write(&data, 0);
}
}
var b []byte = &a;
b = b[0 : p.buflen];
p.buflen = 0;
p.write(b, 0);
// shift remaining entries down
i := 0;
for ; n < len(p.buffer); n++ {
p.buffer[i] = p.buffer[n];
i++;
}
p.buffer = p.buffer[0:i];
}
// ----------------------------------------------------------------------------
// Printing interface
// print prints a list of "items" (roughly corresponding to syntactic
// tokens, but also including whitespace and formatting information).
// It is the only print function that should be called directly from
......@@ -352,21 +480,17 @@ func (p *printer) print(args ...) {
next := p.pos; // estimated position of next item
var data []byte;
switch x := f.Interface().(type) {
case int:
// indentation delta
p.indent += x;
if p.indent < 0 {
panicln("print: negative indentation", p.indent);
}
case whiteSpace:
if p.buflen >= len(p.buffer) {
i := len(p.buffer);
if i == cap(p.buffer) {
// Whitespace sequences are very short so this should
// never happen. Handle gracefully (but possibly with
// bad comment placement) if it does happen.
p.writeWhitespace();
p.writeWhitespace(i);
i = 0;
}
p.buffer[p.buflen] = x;
p.buflen++;
p.buffer = p.buffer[0 : i+1];
p.buffer[i] = x;
case []byte:
data = x;
// do not modify multi-line `` strings!
......@@ -398,6 +522,8 @@ func (p *printer) print(args ...) {
p.flush(next);
// intersperse extra newlines if present in the source
// (don't do this in flush as it will cause extra newlines
// at the end of a file)
p.writeNewlines(next.Line - p.pos.Line);
p.writeItem(next, data, mode);
......@@ -407,16 +533,24 @@ func (p *printer) print(args ...) {
}
// commentBefore returns true iff the current comment occurs
// before the next position in the source code.
//
func (p *printer) commentBefore(next token.Position) bool {
return p.comment != nil && p.comment.List[0].Pos().Offset < next.Offset;
}
// Flush prints any pending comments and whitespace occuring
// textually before the position of the next item.
//
func (p *printer) flush(next token.Position) {
// if there are comments before the next item, intersperse them
if p.comment != nil && p.comment.List[0].Pos().Offset < next.Offset {
if p.commentBefore(next) {
p.intersperseComments(next);
}
p.writeWhitespace();
// write any leftover whitespace
p.writeWhitespace(len(p.buffer));
}
......@@ -426,7 +560,7 @@ func (p *printer) flush(next token.Position) {
// Print as many newlines as necessary (but at least min and and at most
// max newlines) to get to the current line. If newSection is set, the
// first newline is printed as a formfeed. Returns true if any linebreak
// first newline is printed as a formfeed. Returns true if any line break
// was printed; returns false otherwise.
//
// TODO(gri): Reconsider signature (provide position instead of line)
......@@ -477,15 +611,13 @@ func (p *printer) leadComment(d *ast.CommentGroup) {
}
// Print n tabs followed by a line comment.
// Print a tab followed by a line comment.
// A newline must be printed afterwards since
// the comment may be a //-style comment.
func (p *printer) lineComment(n int, d *ast.CommentGroup) {
func (p *printer) lineComment(d *ast.CommentGroup) {
// Ignore the comment if we have comments interspersed (p.comment != nil).
if p.comment == nil && d != nil {
for ; n > 0; n-- {
p.print(vtab);
}
p.commentList(d.List);
}
}
......@@ -551,10 +683,10 @@ func (p *printer) exprList(list []ast.Expr, mode exprListMode) {
// don't add extra indentation if noIndent is set;
// i.e., pretend that the first line is already indented
indented := mode&noIndent != 0;
// there may or may not be a linebreak before the first list
// element; in any case indent once after the first linebreak
// there may or may not be a line break before the first list
// element; in any case indent once after the first line break
if p.linebreak(line, 0, 2, true) && !indented {
p.print(+1);
p.print(htab, indent); // indent applies to next line
indented = true;
}
for i, x := range list {
......@@ -565,10 +697,10 @@ func (p *printer) exprList(list []ast.Expr, mode exprListMode) {
p.print(token.COMMA);
}
if prev < line {
// at least one linebreak, but respect an extra empty line
// at least one line break, but respect an extra empty line
// in the source
if p.linebreak(x.Pos().Line, 1, 2, true) && !indented {
p.print(+1);
p.print(htab, indent); // indent applies to next line
indented = true;
}
} else {
......@@ -582,11 +714,11 @@ func (p *printer) exprList(list []ast.Expr, mode exprListMode) {
if indented && mode&noIndent == 0 {
// should always be indented here since we have a multi-line
// expression list - be conservative and check anyway
p.print(-1);
p.print(unindent);
}
p.print(formfeed); // terminating comma needs a line break to look good
} else if indented && mode&noIndent == 0 {
p.print(-1);
p.print(unindent);
}
}
......@@ -598,9 +730,8 @@ func (p *printer) parameters(list []*ast.Field) {
if i > 0 {
p.print(token.COMMA, blank);
}
p.identList(par.Names);
if len(par.Names) > 0 {
// at least one identifier
p.identList(par.Names);
p.print(blank);
}
p.expr(par.Type);
......@@ -632,33 +763,47 @@ func (p *printer) signature(params, result []*ast.Field) (optSemi bool) {
func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace token.Position, isIncomplete, isStruct bool) {
if len(list) == 0 && !isIncomplete {
if len(list) == 0 && !isIncomplete && !p.commentBefore(rbrace) {
// no blank between keyword and {} in this case
// TODO(gri): This will not look nice if there are comments inside the {}'s.
p.print(lbrace, token.LBRACE, rbrace, token.RBRACE);
return;
}
// at least one entry or incomplete
p.print(blank, lbrace, token.LBRACE, +1, formfeed);
p.print(blank, lbrace, token.LBRACE, indent, formfeed);
if isStruct {
sep := blank;
if len(list) > 1 {
sep = vtab;
sep := vtab;
if len(list) == 1 {
sep = blank;
}
for i, f := range list {
extraTabs := 0;
p.leadComment(f.Doc);
if len(f.Names) > 0 {
p.identList(f.Names);
p.print(sep);
}
p.expr(f.Type);
extraTabs = 1;
} else {
p.expr(f.Type);
extraTabs = 2;
}
if f.Tag != nil {
if len(f.Names) > 0 && sep == vtab {
p.print(sep);
}
p.print(sep);
p.expr(&ast.StringList{f.Tag});
extraTabs = 0;
}
p.print(token.SEMICOLON);
p.lineComment(1, f.Comment);
if f.Comment != nil {
for ; extraTabs > 0; extraTabs-- {
p.print(vtab);
}
p.lineComment(f.Comment);
}
if i+1 < len(list) || isIncomplete {
p.print(newline);
}
......@@ -666,7 +811,9 @@ func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace tok
if isIncomplete {
p.print("// contains unexported fields");
}
} else { // interface
for i, f := range list {
p.leadComment(f.Doc);
if ftyp, isFtyp := f.Type.(*ast.FuncType); isFtyp {
......@@ -678,7 +825,7 @@ func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace tok
p.expr(f.Type);
}
p.print(token.SEMICOLON);
p.lineComment(1, f.Comment);
p.lineComment(f.Comment);
if i+1 < len(list) || isIncomplete {
p.print(newline);
}
......@@ -686,8 +833,9 @@ func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace tok
if isIncomplete {
p.print("// contains unexported methods");
}
}
p.print(-1, formfeed, rbrace, token.RBRACE);
p.print(unindent, formfeed, rbrace, token.RBRACE);
}
......@@ -767,10 +915,10 @@ func (p *printer) binaryExpr(x *ast.BinaryExpr, prec1 int) {
if printBlanks {
if prev != line {
p.print(blank, x.OpPos, x.Op);
// at least one linebreak, but respect an extra empty line
// at least one line break, but respect an extra empty line
// in the source
if p.linebreak(line, 1, 2, false) && !indented {
p.print(+1);
p.print(htab, indent); // indent applies to next line
indented = true;
}
} else {
......@@ -785,7 +933,7 @@ func (p *printer) binaryExpr(x *ast.BinaryExpr, prec1 int) {
p.expr1(x.Y, prec);
}
if indented {
p.print(-1);
p.print(unindent);
}
}
......@@ -838,7 +986,7 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
case *ast.FuncLit:
p.expr(x.Type);
p.print(blank);
p.stmt(x.Body);
p.block(x.Body, 1);
case *ast.ParenExpr:
p.print(token.LPAREN);
......@@ -953,23 +1101,28 @@ const maxStmtNewlines = 2 // maximum number of newlines between statements
// Print the statement list indented, but without a newline after the last statement.
// Extra line breaks between statements in the source are respected but at most one
// empty line is printed between statements.
func (p *printer) stmtList(list []ast.Stmt, indent int) {
p.print(+indent);
func (p *printer) stmtList(list []ast.Stmt, _indent int) {
// TODO(gri): fix _indent code
if _indent > 0 {
p.print(indent);
}
for i, s := range list {
// indent == 0 only for lists of switch/select case clauses;
// _indent == 0 only for lists of switch/select case clauses;
// in those cases each clause is a new section
p.linebreak(s.Pos().Line, 1, maxStmtNewlines, i == 0 || indent == 0);
p.linebreak(s.Pos().Line, 1, maxStmtNewlines, i == 0 || _indent == 0);
if !p.stmt(s) {
p.print(token.SEMICOLON);
}
}
p.print(-indent);
if _indent > 0 {
p.print(unindent);
}
}
func (p *printer) block(s *ast.BlockStmt, indent int) {
p.print(s.Pos(), token.LBRACE);
if len(s.List) > 0 {
if len(s.List) > 0 || p.commentBefore(s.Rbrace) {
p.stmtList(s.List, indent);
p.linebreak(s.Rbrace.Line, 1, maxStmtNewlines, true);
}
......@@ -1039,11 +1192,12 @@ func (p *printer) stmt(stmt ast.Stmt) (optSemi bool) {
// nothing to do
case *ast.LabeledStmt:
// whitespace printing is delayed, thus indentation adjustments
// take place before the previous newline/formfeed is printed
p.print(-1);
// a "correcting" unindent immediately following a line break
// is applied before the line break if there is no comment
// between (see writeWhitespace)
p.print(unindent);
p.expr(s.Label);
p.print(token.COLON, vtab, +1);
p.print(token.COLON, vtab, indent);
p.linebreak(s.Stmt.Pos().Line, 0, 1, true);
optSemi = p.stmt(s.Stmt);
......@@ -1095,9 +1249,9 @@ func (p *printer) stmt(stmt ast.Stmt) (optSemi bool) {
case *ast.BlockStmt, *ast.IfStmt:
optSemi = p.stmt(s.Else);
default:
p.print(token.LBRACE, +1, formfeed);
p.print(token.LBRACE, indent, formfeed);
p.stmt(s.Else);
p.print(-1, formfeed, token.RBRACE);
p.print(unindent, formfeed, token.RBRACE);
}
}
......@@ -1207,29 +1361,22 @@ func (p *printer) spec(spec ast.Spec, n int, context declContext) {
var (
optSemi bool; // true if a semicolon is optional
comment *ast.CommentGroup; // a line comment, if any
columns int; // number of (discardable) columns missing before comment, if any
extraTabs int; // number of extra tabs before comment, if any
)
switch s := spec.(type) {
case *ast.ImportSpec:
p.leadComment(s.Doc);
if n == 1 {
if s.Name != nil {
p.expr(s.Name);
p.print(blank);
}
} else {
if s.Name != nil {
p.expr(s.Name);
}
p.print(vtab); // column discarded if empty
}
p.expr(&ast.StringList{s.Path});
comment = s.Comment;
case *ast.ValueSpec:
p.leadComment(s.Doc);
p.identList(s.Names); // never empty
p.identList(s.Names); // always present
if n == 1 {
if s.Type != nil {
p.print(blank);
......@@ -1241,20 +1388,20 @@ func (p *printer) spec(spec ast.Spec, n int, context declContext) {
optSemi = false;
}
} else {
columns = 2;
extraTabs = 2;
if s.Type != nil || s.Values != nil {
p.print(vtab);
}
if s.Type != nil {
optSemi = p.expr(s.Type);
columns = 1;
extraTabs = 1;
}
if s.Values != nil {
p.print(vtab);
p.print(token.ASSIGN);
p.exprList(s.Values, blankStart | commaSep);
optSemi = false;
columns = 0;
extraTabs = 0;
}
}
comment = s.Comment;
......@@ -1278,7 +1425,12 @@ func (p *printer) spec(spec ast.Spec, n int, context declContext) {
p.print(token.SEMICOLON);
}
p.lineComment(1+columns, comment);
if comment != nil {
for ; extraTabs > 0; extraTabs-- {
p.print(vtab);
}
p.lineComment(comment);
}
}
......@@ -1295,14 +1447,14 @@ func (p *printer) decl(decl ast.Decl, context declContext) {
// group of parenthesized declarations
p.print(d.Lparen, token.LPAREN);
if len(d.Specs) > 0 {
p.print(+1, formfeed);
p.print(indent, formfeed);
for i, s := range d.Specs {
if i > 0 {
p.print(newline);
}
p.spec(s, len(d.Specs), inGroup);
}
p.print(-1, formfeed);
p.print(unindent, formfeed);
}
p.print(d.Rparen, token.RPAREN);
......@@ -1328,7 +1480,7 @@ func (p *printer) decl(decl ast.Decl, context declContext) {
p.signature(d.Type.Params, d.Type.Results);
if d.Body != nil {
p.print(blank);
p.stmt(d.Body);
p.block(d.Body, 1);
}
default:
......
src/pkg/go/printer/testdata/comments.go
View file @ df7efaf9
......@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This is a package for testing purposes.
// This is a package for testing comment placement by go/printer.
//
package main
......@@ -53,7 +53,7 @@ type I1 interface {
}
// The I2 interface; all methods are exported.
type I1 interface {
type I2 interface {
I0;
F(x float) float; // exported method
G(x float) float; // exported method
......@@ -91,6 +91,11 @@ func f1() {
}
func _() {
// this comment should be properly indented
}
func abs(x int) int {
if x < 0 { // the tab printed before this comment's // must not affect the remaining lines
return -x; // this statement should be properly indented
......@@ -114,9 +119,26 @@ func typeswitch(x interface{}) {
switch v0, ok := x.(int); x.(type) {
case bool, int, float:
// this comment should be indented
case string:
default:
// this comment should be indented
}
// this comment should be indented
}
// Line comments with tabs
func _() {
var finput *bufio.Reader; // input file
var stderr *bufio.Writer;
var ftable *bufio.Writer; // y.go file
var foutput *bufio.Writer; // y.output file
var oflag string; // -o [y.go] - y.go file
var vflag string; // -v [y.output] - y.output file
var lflag bool; // -l - disable line directives
}
// This comment is the last entry in this file. It must be printed.
src/pkg/go/printer/testdata/comments.golden
View file @ df7efaf9
......@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This is a package for testing purposes.
// This is a package for testing comment placement by go/printer.
//
package main
......@@ -53,7 +53,7 @@ type I1 interface {
}
// The I2 interface; all methods are exported.
type I1 interface {
type I2 interface {
I0;
F(x float) float; // exported method
G(x float) float; // exported method
......@@ -91,6 +91,11 @@ func f1() {
}
func _() {
// this comment should be properly indented
}
func abs(x int) int {
if x < 0 { // the tab printed before this comment's // must not affect the remaining lines
return -x; // this statement should be properly indented
......@@ -112,9 +117,26 @@ func typeswitch(x interface{}) {
switch v0, ok := x.(int); x.(type) {
case bool, int, float:
// this comment should be indented
case string:
default:
// this comment should be indented
}
// this comment should be indented
}
// Line comments with tabs
func _() {
var finput *bufio.Reader; // input file
var stderr *bufio.Writer;
var ftable *bufio.Writer; // y.go file
var foutput *bufio.Writer; // y.output file
var oflag string; // -o [y.go] - y.go file
var vflag string; // -v [y.output] - y.output file
var lflag bool; // -l - disable line directives
}
// This comment is the last entry in this file. It must be printed.
src/pkg/go/printer/testdata/comments.x
View file @ df7efaf9
// This is a package for testing purposes.
// This is a package for testing comment placement by go/printer.
//
package main
......@@ -48,7 +48,7 @@ type I1 interface {
// The I2 interface; all methods are exported.
type I1 interface {
type I2 interface {
I0;
F(x float) float;
G(x float) float;
......
src/pkg/go/printer/testdata/declarations.go
View file @ df7efaf9
......@@ -175,6 +175,14 @@ func _() {
y = 20; // comment
f, ff, fff, ffff int = 0, 1, 2, 3; // comment
)
// respect original line breaks
var _ = []T {
T{0x20, "Telugu"}
};
var _ = []T {
// respect original line breaks
T{0x20, "Telugu"}
};
}
func _() {
......@@ -194,7 +202,13 @@ func _() {
// formatting of structs
type ES struct{}
type _ struct{}
type _ struct{ /* this comment should be visible */ }
type _ struct{
// this comment should be visible and properly indented
}
type _ struct { // this comment must not change indentation
f int;
......
src/pkg/go/printer/testdata/declarations.golden
View file @ df7efaf9
......@@ -173,6 +173,11 @@ func _() {
y = 20; // comment
f, ff, fff, ffff int = 0, 1, 2, 3; // comment
)
// respect original line breaks
var _ = []T{T{0x20, "Telugu"}};
var _ = []T{
// respect original line breaks
T{0x20, "Telugu"}};
}
func _() {
......@@ -192,7 +197,13 @@ func _() {
// formatting of structs
type ES struct{}
type _ struct{}
type _ struct { /* this comment should be visible */}
type _ struct {
// this comment should be visible and properly indented
}
type _ struct { // this comment must not change indentation
f int;
......
src/pkg/go/printer/testdata/expressions.go
View file @ df7efaf9
......@@ -165,3 +165,14 @@ func (p *parser) charClass() {
p.re.add(nl);
}
}
func addState(s []state, inst instr, match []int) {
// handle comments correctly in multi-line expressions
for i := 0; i < l; i++ {
if s[i].inst.index() == index && // same instruction
s[i].match[0] < pos { // earlier match already going; leftmost wins
return s
}
}
}
src/pkg/go/printer/testdata/expressions.golden
View file @ df7efaf9
......@@ -108,11 +108,9 @@ func _() {
// do not modify `` strings
_ = ``;
_ = `
`;
// TODO(gri): fix line breaks here
`; // TODO(gri): fix line breaks here
_ = `foo
bar`;
}
......@@ -140,8 +138,8 @@ func _() {
b < a;
_ = "1234567890"
"1234567890";
// TODO(gri): add more test cases
// TODO(gri): these comments should be indented
// TODO(gri): add more test cases
// TODO(gri): these comments should be indented
}
......@@ -167,3 +165,15 @@ func (p *parser) charClass() {
p.re.add(nl);
}
}
func addState(s []state, inst instr, match []int) {
// handle comments correctly in multi-line expressions
for i := 0; i < l; i++ {
if s[i].inst.index() == index &&
// same instruction
s[i].match[0] < pos { // earlier match already going; leftmost wins
return s;
}
}
}
src/pkg/go/printer/testdata/linebreaks.golden
View file @ df7efaf9
......@@ -181,6 +181,8 @@ var facts = map[int]string{
func usage() {
fmt.Fprintf(os.Stderr,
// TODO(gri): the 2nd string of this string list should not be indented
"usage: godoc package [name ...]\n"
" godoc -http=:6060\n");
......
src/pkg/go/printer/testdata/statements.go
View file @ df7efaf9
......@@ -123,6 +123,18 @@ func _() {
func _() {
// this comment should be indented
L:
}
func _() {
L: _ = 0;
}
func _() {
// this comment should be indented
L: _ = 0;
}
......@@ -134,3 +146,13 @@ func _() {
_ = 0;
}
}
func _() {
// this comment should be indented
for {
L1: _ = 0;
L2:
_ = 0;
}
}
src/pkg/go/printer/testdata/statements.golden
View file @ df7efaf9
......@@ -139,6 +139,19 @@ L:
func _() {
// this comment should be indented
L:
;
}
func _() {
L: _ = 0;
}
func _() {
// this comment should be indented
L: _ = 0;
}
......@@ -150,3 +163,13 @@ func _() {
_ = 0;
}
}
func _() {
// this comment should be indented
for {
L1: _ = 0;
L2:
_ = 0;
}
}
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