Add flag -tabindent to gofmt: forces use of

tabs for indentation even if -spaces is set.

Changes to gofmt:
- added -tabindent flag
- don't recompute parser and printer mode repeatedly

Changes to go/printer:
- provide new printing mode TabIndent

Changes to tabwriter:
- implement new mode TabIndent to use tabs independent
  of the actual padding character for leading empty columns
- distinguish between minimal cell width and tab width
  (tabwidth is only used if the output contains tabs,
  minwidth and padding are always considered)
- fixed and added more comments
- some additional factoring

By default, -tabindent is disabled and the default gofmt
behavior is unchanged. By setting -spaces and -tabindent,
gofmt will use tabs for indentation but do any other
alignment with spaces. This permits a user to change the
visible indentation by simply changing the editor's tab
width and the code will remain properly aligned without
the need to rerun gofmt.

R=rsc
https://golang.org/cl/163068

src/cmd/gofmt/gofmt.go

@@ -31,12 +31,17 @@ var (
 
 	// layout control
 	tabwidth	= flag.Int("tabwidth", 8, "tab width");
+	tabindent	= flag.Bool("tabindent", false, "indent with tabs independent of -spaces");
 	usespaces	= flag.Bool("spaces", false, "align with spaces instead of tabs");
 )
 
 
-var exitCode = 0
-var rewrite func(*ast.File) *ast.File
+var (
+	exitCode	= 0;
+	rewrite		func(*ast.File) *ast.File;
+	parserMode	uint;
+	printerMode	uint;
+)
 
 
 func report(err os.Error) {
@@ -52,24 +57,25 @@ func usage() {
 }
 
 
-func parserMode() uint {
-	mode := uint(0);
+func initParserMode() {
+	parserMode = uint(0);
 	if *comments {
-		mode |= parser.ParseComments
+		parserMode |= parser.ParseComments
 	}
 	if *trace {
-		mode |= parser.Trace
+		parserMode |= parser.Trace
 	}
-	return mode;
 }
 
 
-func printerMode() uint {
-	mode := uint(0);
+func initPrinterMode() {
+	printerMode = uint(0);
+	if *tabindent {
+		printerMode |= printer.TabIndent
+	}
 	if *usespaces {
-		mode |= printer.UseSpaces
+		printerMode |= printer.UseSpaces
 	}
-	return mode;
 }
 
 
@@ -85,7 +91,7 @@ func processFile(f *os.File) os.Error {
 		return err
 	}
 
-	file, err := parser.ParseFile(f.Name(), src, parserMode());
+	file, err := parser.ParseFile(f.Name(), src, parserMode);
 	if err != nil {
 		return err
 	}
@@ -95,7 +101,7 @@ func processFile(f *os.File) os.Error {
 	}
 
 	var res bytes.Buffer;
-	_, err = (&printer.Config{printerMode(), *tabwidth, nil}).Fprint(&res, file);
+	_, err = (&printer.Config{printerMode, *tabwidth, nil}).Fprint(&res, file);
 	if err != nil {
 		return err
 	}
@@ -175,6 +181,8 @@ func main() {
 		os.Exit(2);
 	}
 
+	initParserMode();
+	initPrinterMode();
 	initRewrite();
 
 	if flag.NArg() == 0 {

src/pkg/go/printer/printer.go

@@ -892,7 +892,8 @@ func (p *trimmer) Write(data []byte) (n int, err os.Error) {
 const (
 	GenHTML		uint	= 1 << iota;	// generate HTML
 	RawFormat;		// do not use a tabwriter; if set, UseSpaces is ignored
-	UseSpaces;		// use spaces instead of tabs for indentation and alignment
+	TabIndent;		// use tabs for indentation independent of UseSpaces
+	UseSpaces;		// use spaces instead of tabs for alignment
 )
 
 
@@ -937,15 +938,23 @@ func (cfg *Config) Fprint(output io.Writer, node interface{}) (int, os.Error) {
 	// setup tabwriter if needed and redirect output
 	var tw *tabwriter.Writer;
 	if cfg.Mode&RawFormat == 0 {
+		minwidth := cfg.Tabwidth;
+
 		padchar := byte('\t');
 		if cfg.Mode&UseSpaces != 0 {
 			padchar = ' '
 		}
+
 		twmode := tabwriter.DiscardEmptyColumns;
 		if cfg.Mode&GenHTML != 0 {
 			twmode |= tabwriter.FilterHTML
 		}
-		tw = tabwriter.NewWriter(output, cfg.Tabwidth, 1, padchar, twmode);
+		if cfg.Mode&TabIndent != 0 {
+			minwidth = 0;
+			twmode |= tabwriter.TabIndent;
+		}
+
+		tw = tabwriter.NewWriter(output, minwidth, cfg.Tabwidth, 1, padchar, twmode);
 		output = tw;
 	}
 

src/pkg/tabwriter/tabwriter.go

@@ -22,10 +22,10 @@ import (
 // ----------------------------------------------------------------------------
 // Filter implementation
 
-// A cell represents a segment of text delineated by tabs, formfeed,
-// or newline chars. The text itself is stored in a separate buffer;
-// cell only describes the segment's size in bytes, its width in runes,
-// and whether it's an htab ('\t') or vtab ('\v') terminated call.
+// A cell represents a segment of text terminated by tabs or line breaks.
+// The text itself is stored in a separate buffer; cell only describes the
+// segment's size in bytes, its width in runes, and whether it's an htab
+// ('\t') terminated cell.
 //
 type cell struct {
 	size	int;	// cell size in bytes
@@ -38,15 +38,16 @@ type cell struct {
 // tab-delimited columns in its input to align them
 // in the output.
 //
-// The Writer treats incoming bytes as UTF-8 encoded text
-// consisting of tab-terminated cells. Cells in adjacent lines
-// constitute a column. The Writer inserts padding as needed
-// to make all cells in a column have the same width, effectively
-// aligning the columns. Note that cells are tab-terminated,
-// not tab-separated: trailing non-tab text at the end of a line
-// is not part of any cell.
+// The Writer treats incoming bytes as UTF-8 encoded text consisting
+// of cells terminated by (horizontal or vertical) tabs or line
+// breaks (newline or formfeed characters). Cells in adjacent lines
+// constitute a column. The Writer inserts padding as needed to
+// make all cells in a column have the same width, effectively
+// aligning the columns. It assumes that all characters have the
+// same width except for tabs for which a tabwidth must be specified.
+// Note that cells are tab-terminated, not tab-separated: trailing
+// non-tab text at the end of a line does not form a column cell.
 //
-// Horizontal and vertical tabs may be used to terminate a cell.
 // If DiscardEmptyColumns is set, empty columns that are terminated
 // entirely by vertical (or "soft") tabs are discarded. Columns
 // terminated by horizontal (or "hard") tabs are not affected by
@@ -78,17 +79,18 @@ type cell struct {
 type Writer struct {
 	// configuration
 	output		io.Writer;
-	cellwidth	int;
+	minwidth	int;
+	tabwidth	int;
 	padding		int;
 	padbytes	[8]byte;
 	flags		uint;
 
 	// current state
-	buf	bytes.Buffer;		// collected text w/o tabs, newlines, or formfeed chars
-	pos	int;			// buffer position up to which width of incomplete cell has been computed
-	cell	cell;			// current incomplete cell; cell.width is up to buf[pos] w/o ignored sections
+	buf	bytes.Buffer;		// collected text excluding tabs or line breaks
+	pos	int;			// buffer position up to which cell.width of incomplete cell has been computed
+	cell	cell;			// current incomplete cell; cell.width is up to buf[pos] excluding ignored sections
 	endChar	byte;			// terminating char of escaped sequence (Escape for escapes, '>', ';' for HTML tags/entities, or 0)
-	lines	vector.Vector;		// list if lines; each line is a list of cells
+	lines	vector.Vector;		// list of lines; each line is a list of cells
 	widths	vector.IntVector;	// list of column widths in runes - re-used during formatting
 }
 
@@ -113,9 +115,9 @@ func (b *Writer) reset() {
 
 // Internal representation (current state):
 //
-// - all text written is appended to buf; formfeed chars, tabs and newlines are stripped away
+// - all text written is appended to buf; tabs and line breaks are stripped away
 // - at any given time there is a (possibly empty) incomplete cell at the end
-//   (the cell starts after a tab, formfeed, or newline)
+//   (the cell starts after a tab or line break)
 // - cell.size is the number of bytes belonging to the cell so far
 // - cell.width is text width in runes of that cell from the start of the cell to
 //   position pos; html tags and entities are excluded from this width if html
@@ -149,6 +151,10 @@ const (
 	// the input in the first place.
 	DiscardEmptyColumns;
 
+	// Always use tabs for indentation columns (i.e., padding of
+	// leading empty cells on the left) independent of padchar.
+	TabIndent;
+
 	// Print a vertical bar ('|') between columns (after formatting).
 	// Discarded colums appear as zero-width columns ("||").
 	Debug;
@@ -158,37 +164,36 @@ const (
 // A Writer must be initialized with a call to Init. The first parameter (output)
 // specifies the filter output. The remaining parameters control the formatting:
 //
-//	cellwidth	minimal cell width
-//	padding		cell padding added to cell before computing its width
+//	minwidth	minimal cell width including any padding
+//      tabwidth	width of tab characters (equivalent number of spaces)
+//	padding		padding added to a cell before computing its width
 //	padchar		ASCII char used for padding
 //			if padchar == '\t', the Writer will assume that the
-//			width of a '\t' in the formatted output is cellwidth,
+//			width of a '\t' in the formatted output is tabwidth,
 //			and cells are left-aligned independent of align_left
-//			(for correct-looking results, cellwidth must correspond
+//			(for correct-looking results, tabwidth must correspond
 //			to the tab width in the viewer displaying the result)
 //	flags		formatting control
 //
 // To format in tab-separated columns with a tab stop of 8:
-//	b.Init(w, 8, 1, '\t', 0);
+//	b.Init(w, 8, 1, 8, '\t', 0);
 //
 // To format in space-separated columns with at least 4 spaces between columns:
-//	b.Init(w, 1, 4, ' ', 0);
+//	b.Init(w, 0, 4, 8, ' ', 0);
 //
-func (b *Writer) Init(output io.Writer, cellwidth, padding int, padchar byte, flags uint) *Writer {
-	if cellwidth < 0 {
-		panic("negative cellwidth")
-	}
-	if padding < 0 {
-		panic("negative padding")
+func (b *Writer) Init(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *Writer {
+	if minwidth < 0 || tabwidth < 0 || padding < 0 {
+		panic("negative minwidth, tabwidth, or padding")
 	}
 	b.output = output;
-	b.cellwidth = cellwidth;
+	b.minwidth = minwidth;
+	b.tabwidth = tabwidth;
 	b.padding = padding;
-	for i := len(b.padbytes) - 1; i >= 0; i-- {
+	for i := range b.padbytes {
 		b.padbytes[i] = padchar
 	}
 	if padchar == '\t' {
-		// tab enforces left-alignment
+		// tab padding enforces left-alignment
 		flags &^= AlignRight
 	}
 	b.flags = flags;
@@ -200,22 +205,20 @@ func (b *Writer) Init(output io.Writer, cellwidth, padding int, padchar byte, fl
 
 
 // debugging support (keep code around)
-/*
 func (b *Writer) dump() {
 	pos := 0;
-	for i := 0; i < b.lines_size.Len(); i++ {
-		line_size, line_width := b.line(i);
+	for i := 0; i < b.lines.Len(); i++ {
+		line := b.line(i);
 		print("(", i, ") ");
-		for j := 0; j < line_size.Len(); j++ {
-			s := line_size.At(j);
-			print("[", string(b.buf.slice(pos, pos + s)), "]");
-			pos += s;
+		for j := 0; j < line.Len(); j++ {
+			c := line.At(j).(cell);
+			print("[", string(b.buf.Bytes()[pos:pos+c.size]), "]");
+			pos += c.size;
 		}
 		print("\n");
 	}
 	print("\n");
 }
-*/
 
 
 func (b *Writer) write0(buf []byte) os.Error {
@@ -227,35 +230,40 @@ func (b *Writer) write0(buf []byte) os.Error {
 }
 
 
-var newline = []byte{'\n'}
-
-func (b *Writer) writePadding(textw, cellw int) os.Error {
-	if b.cellwidth == 0 {
-		return nil
+func (b *Writer) writeN(src []byte, n int) os.Error {
+	for n > len(src) {
+		if err := b.write0(src); err != nil {
+			return err
+		}
+		n -= len(src);
 	}
+	return b.write0(src[0:n]);
+}
 
-	if b.padbytes[0] == '\t' {
-		// make cell width a multiple of cellwidth
-		cellw = ((cellw + b.cellwidth - 1) / b.cellwidth) * b.cellwidth
-	}
 
-	n := cellw - textw;
-	if n < 0 {
-		panic("internal error")
-	}
+var (
+	newline	= []byte{'\n'};
+	tabs	= []byte{'\t', '\t', '\t', '\t', '\t', '\t', '\t', '\t'};
+)
 
-	if b.padbytes[0] == '\t' {
-		n = (n + b.cellwidth - 1) / b.cellwidth
-	}
 
-	for n > len(b.padbytes) {
-		if err := b.write0(&b.padbytes); err != nil {
-			return err
+func (b *Writer) writePadding(textw, cellw int, useTabs bool) os.Error {
+	if b.padbytes[0] == '\t' || useTabs {
+		// padding is done with tabs
+		if b.tabwidth == 0 {
+			return nil	// tabs have no width - can't do any padding
 		}
-		n -= len(b.padbytes);
+		// make cellw the smallest multiple of b.tabwidth
+		cellw = (cellw + b.tabwidth - 1) / b.tabwidth * b.tabwidth;
+		n := cellw - textw;	// amount of padding
+		if n < 0 {
+			panic("internal error")
+		}
+		return b.writeN(tabs, (n+b.tabwidth-1)/b.tabwidth);
 	}
 
-	return b.write0(b.padbytes[0:n]);
+	// padding is done with non-tab characters
+	return b.writeN(&b.padbytes, cellw-textw);
 }
 
 
@@ -265,6 +273,10 @@ func (b *Writer) writeLines(pos0 int, line0, line1 int) (pos int, err os.Error)
 	pos = pos0;
 	for i := line0; i < line1; i++ {
 		line := b.line(i);
+
+		// if TabIndent is set, use tabs to pad leading empty cells
+		useTabs := b.flags&TabIndent != 0;
+
 		for j := 0; j < line.Len(); j++ {
 			c := line.At(j).(cell);
 
@@ -273,30 +285,38 @@ func (b *Writer) writeLines(pos0 int, line0, line1 int) (pos int, err os.Error)
 					return
 				}
 			}
-			switch {
-			default:	// align left
 
-				if err = b.write0(b.buf.Bytes()[pos : pos+c.size]); err != nil {
-					return
-				}
-				pos += c.size;
+			if c.size == 0 {
+				// empty cell
 				if j < b.widths.Len() {
-					if err = b.writePadding(c.width, b.widths.At(j)); err != nil {
+					if err = b.writePadding(c.width, b.widths.At(j), useTabs); err != nil {
 						return
 					}
 				}
-
-			case b.flags&AlignRight != 0:	// align right
-
-				if j < b.widths.Len() {
-					if err = b.writePadding(c.width, b.widths.At(j)); err != nil {
+			} else {
+				// non-empty cell
+				useTabs = false;
+				if b.flags&AlignRight == 0 {	// align left
+					if err = b.write0(b.buf.Bytes()[pos : pos+c.size]); err != nil {
 						return
 					}
+					pos += c.size;
+					if j < b.widths.Len() {
+						if err = b.writePadding(c.width, b.widths.At(j), false); err != nil {
+							return
+						}
+					}
+				} else {	// align right
+					if j < b.widths.Len() {
+						if err = b.writePadding(c.width, b.widths.At(j), false); err != nil {
+							return
+						}
+					}
+					if err = b.write0(b.buf.Bytes()[pos : pos+c.size]); err != nil {
+						return
+					}
+					pos += c.size;
 				}
-				if err = b.write0(b.buf.Bytes()[pos : pos+c.size]); err != nil {
-					return
-				}
-				pos += c.size;
 			}
 		}
 
@@ -344,7 +364,7 @@ func (b *Writer) format(pos0 int, line0, line1 int) (pos int, err os.Error) {
 			line0 = this;
 
 			// column block begin
-			width := b.cellwidth;	// minimal column width
+			width := b.minwidth;	// minimal column width
 			discardable := true;	// true if all cells in this column are empty and "soft"
 			for ; this < line1; this++ {
 				line = b.line(this);
@@ -551,6 +571,6 @@ func (b *Writer) Write(buf []byte) (n int, err os.Error) {
 // NewWriter allocates and initializes a new tabwriter.Writer.
 // The parameters are the same as for the the Init function.
 //
-func NewWriter(output io.Writer, cellwidth, padding int, padchar byte, flags uint) *Writer {
-	return new(Writer).Init(output, cellwidth, padding, padchar, flags)
+func NewWriter(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *Writer {
+	return new(Writer).Init(output, minwidth, tabwidth, padding, padchar, flags)
 }

src/pkg/tabwriter/tabwriter_test.go

@@ -64,12 +64,12 @@ func verify(t *testing.T, testname string, w *Writer, b *buffer, src, expected s
 }
 
 
-func check(t *testing.T, testname string, tabwidth, padding int, padchar byte, flags uint, src, expected string) {
+func check(t *testing.T, testname string, minwidth, tabwidth, padding int, padchar byte, flags uint, src, expected string) {
 	var b buffer;
 	b.init(1000);
 
 	var w Writer;
-	w.Init(&b, tabwidth, padding, padchar, flags);
+	w.Init(&b, minwidth, tabwidth, padding, padchar, flags);
 
 	// write all at once
 	b.clear();
@@ -97,193 +97,193 @@ func check(t *testing.T, testname string, tabwidth, padding int, padchar byte, f
 
 
 type entry struct {
-	testname		string;
-	tabwidth, padding	int;
-	padchar			byte;
-	flags			uint;
-	src, expected		string;
+	testname			string;
+	minwidth, tabwidth, padding	int;
+	padchar				byte;
+	flags				uint;
+	src, expected			string;
 }
 
 
 var tests = []entry{
 	entry{
 		"1a",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"",
 		"",
 	},
 
 	entry{
 		"1a debug",
-		8, 1, '.', Debug,
+		8, 0, 1, '.', Debug,
 		"",
 		"",
 	},
 
 	entry{
 		"1b esc",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"\xff\xff",
 		"",
 	},
 
 	entry{
 		"1c esc",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"\xff\t\xff",
 		"\t",
 	},
 
 	entry{
 		"1d esc",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"\xff\"foo\t\n\tbar\"\xff",
 		"\"foo\t\n\tbar\"",
 	},
 
 	entry{
 		"1e esc",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"abc\xff\tdef",	// unterminated escape
 		"abc\tdef",
 	},
 
 	entry{
 		"2",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"\n\n\n",
 		"\n\n\n",
 	},
 
 	entry{
 		"3",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"a\nb\nc",
 		"a\nb\nc",
 	},
 
 	entry{
 		"4a",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"\t",	// '\t' terminates an empty cell on last line - nothing to print
 		"",
 	},
 
 	entry{
 		"4b",
-		8, 1, '.', AlignRight,
+		8, 0, 1, '.', AlignRight,
 		"\t",	// '\t' terminates an empty cell on last line - nothing to print
 		"",
 	},
 
 	entry{
 		"5",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"*\t*",
 		"*.......*",
 	},
 
 	entry{
 		"5b",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"*\t*\n",
 		"*.......*\n",
 	},
 
 	entry{
 		"5c",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"*\t*\t",
 		"*.......*",
 	},
 
 	entry{
 		"5c debug",
-		8, 1, '.', Debug,
+		8, 0, 1, '.', Debug,
 		"*\t*\t",
 		"*.......|*",
 	},
 
 	entry{
 		"5d",
-		8, 1, '.', AlignRight,
+		8, 0, 1, '.', AlignRight,
 		"*\t*\t",
 		".......**",
 	},
 
 	entry{
 		"6",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"\t\n",
 		"........\n",
 	},
 
 	entry{
 		"7a",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"a) foo",
 		"a) foo",
 	},
 
 	entry{
 		"7b",
-		8, 1, ' ', 0,
+		8, 0, 1, ' ', 0,
 		"b) foo\tbar",
 		"b) foo  bar",
 	},
 
 	entry{
 		"7c",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"c) foo\tbar\t",
 		"c) foo..bar",
 	},
 
 	entry{
 		"7d",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"d) foo\tbar\n",
 		"d) foo..bar\n",
 	},
 
 	entry{
 		"7e",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"e) foo\tbar\t\n",
 		"e) foo..bar.....\n",
 	},
 
 	entry{
 		"7f",
-		8, 1, '.', FilterHTML,
+		8, 0, 1, '.', FilterHTML,
 		"f) f&lt;o\t<b>bar</b>\t\n",
 		"f) f&lt;o..<b>bar</b>.....\n",
 	},
 
 	entry{
 		"7g",
-		8, 1, '.', FilterHTML,
+		8, 0, 1, '.', FilterHTML,
 		"g) f&lt;o\t<b>bar</b>\t non-terminated entity &amp",
 		"g) f&lt;o..<b>bar</b>..... non-terminated entity &amp",
 	},
 
 	entry{
 		"7g debug",
-		8, 1, '.', FilterHTML | Debug,
+		8, 0, 1, '.', FilterHTML | Debug,
 		"g) f&lt;o\t<b>bar</b>\t non-terminated entity &amp",
 		"g) f&lt;o..|<b>bar</b>.....| non-terminated entity &amp",
 	},
 
 	entry{
 		"8",
-		8, 1, '*', 0,
+		8, 0, 1, '*', 0,
 		"Hello, world!\n",
 		"Hello, world!\n",
 	},
 
 	entry{
 		"9a",
-		1, 0, '.', 0,
+		1, 0, 0, '.', 0,
 		"1\t2\t3\t4\n"
 			"11\t222\t3333\t44444\n",
 
@@ -293,7 +293,7 @@ var tests = []entry{
 
 	entry{
 		"9b",
-		1, 0, '.', FilterHTML,
+		1, 0, 0, '.', FilterHTML,
 		"1\t2<!---\f--->\t3\t4\n"	// \f inside HTML is ignored
 			"11\t222\t3333\t44444\n",
 
@@ -303,7 +303,7 @@ var tests = []entry{
 
 	entry{
 		"9c",
-		1, 0, '.', 0,
+		1, 0, 0, '.', 0,
 		"1\t2\t3\t4\f"	// \f causes a newline and flush
 			"11\t222\t3333\t44444\n",
 
@@ -313,7 +313,7 @@ var tests = []entry{
 
 	entry{
 		"9c debug",
-		1, 0, '.', Debug,
+		1, 0, 0, '.', Debug,
 		"1\t2\t3\t4\f"	// \f causes a newline and flush
 			"11\t222\t3333\t44444\n",
 
@@ -323,21 +323,21 @@ var tests = []entry{
 
 	entry{
 		"10a",
-		5, 0, '.', 0,
+		5, 0, 0, '.', 0,
 		"1\t2\t3\t4\n",
 		"1....2....3....4\n",
 	},
 
 	entry{
 		"10b",
-		5, 0, '.', 0,
+		5, 0, 0, '.', 0,
 		"1\t2\t3\t4\t\n",
 		"1....2....3....4....\n",
 	},
 
 	entry{
 		"11",
-		8, 1, '.', 0,
+		8, 0, 1, '.', 0,
 		"本\tb\tc\n"
 			"aa\t\u672c\u672c\u672c\tcccc\tddddd\n"
 			"aaa\tbbbb\n",
@@ -349,7 +349,7 @@ var tests = []entry{
 
 	entry{
 		"12a",
-		8, 1, ' ', AlignRight,
+		8, 0, 1, ' ', AlignRight,
 		"a\tè\tc\t\n"
 			"aa\tèèè\tcccc\tddddd\t\n"
 			"aaa\tèèèè\t\n",
@@ -361,7 +361,7 @@ var tests = []entry{
 
 	entry{
 		"12b",
-		2, 0, ' ', 0,
+		2, 0, 0, ' ', 0,
 		"a\tb\tc\n"
 			"aa\tbbb\tcccc\n"
 			"aaa\tbbbb\n",
@@ -373,7 +373,7 @@ var tests = []entry{
 
 	entry{
 		"12c",
-		8, 1, '_', 0,
+		8, 0, 1, '_', 0,
 		"a\tb\tc\n"
 			"aa\tbbb\tcccc\n"
 			"aaa\tbbbb\n",
@@ -385,7 +385,7 @@ var tests = []entry{
 
 	entry{
 		"13a",
-		4, 1, '-', 0,
+		4, 0, 1, '-', 0,
 		"4444\t日本語\t22\t1\t333\n"
 			"999999999\t22\n"
 			"7\t22\n"
@@ -405,7 +405,7 @@ var tests = []entry{
 
 	entry{
 		"13b",
-		4, 3, '.', 0,
+		4, 0, 3, '.', 0,
 		"4444\t333\t22\t1\t333\n"
 			"999999999\t22\n"
 			"7\t22\n"
@@ -425,7 +425,7 @@ var tests = []entry{
 
 	entry{
 		"13c",
-		8, 1, '\t', FilterHTML,
+		8, 8, 1, '\t', FilterHTML,
 		"4444\t333\t22\t1\t333\n"
 			"999999999\t22\n"
 			"7\t22\n"
@@ -445,7 +445,7 @@ var tests = []entry{
 
 	entry{
 		"14",
-		1, 2, ' ', AlignRight,
+		1, 0, 2, ' ', AlignRight,
 		".0\t.3\t2.4\t-5.1\t\n"
 			"23.0\t12345678.9\t2.4\t-989.4\t\n"
 			"5.1\t12.0\t2.4\t-7.0\t\n"
@@ -463,7 +463,7 @@ var tests = []entry{
 
 	entry{
 		"14 debug",
-		1, 2, ' ', AlignRight | Debug,
+		1, 0, 2, ' ', AlignRight | Debug,
 		".0\t.3\t2.4\t-5.1\t\n"
 			"23.0\t12345678.9\t2.4\t-989.4\t\n"
 			"5.1\t12.0\t2.4\t-7.0\t\n"
@@ -481,35 +481,35 @@ var tests = []entry{
 
 	entry{
 		"15a",
-		4, 0, '.', 0,
+		4, 0, 0, '.', 0,
 		"a\t\tb",
 		"a.......b",
 	},
 
 	entry{
 		"15b",
-		4, 0, '.', DiscardEmptyColumns,
+		4, 0, 0, '.', DiscardEmptyColumns,
 		"a\t\tb",	// htabs - do not discard column
 		"a.......b",
 	},
 
 	entry{
 		"15c",
-		4, 0, '.', DiscardEmptyColumns,
+		4, 0, 0, '.', DiscardEmptyColumns,
 		"a\v\vb",
 		"a...b",
 	},
 
 	entry{
 		"15d",
-		4, 0, '.', AlignRight | DiscardEmptyColumns,
+		4, 0, 0, '.', AlignRight | DiscardEmptyColumns,
 		"a\v\vb",
 		"...ab",
 	},
 
 	entry{
 		"16a",
-		100, 0, '\t', 0,
+		100, 100, 0, '\t', 0,
 		"a\tb\t\td\n"
 			"a\tb\t\td\te\n"
 			"a\n"
@@ -525,7 +525,7 @@ var tests = []entry{
 
 	entry{
 		"16b",
-		100, 0, '\t', DiscardEmptyColumns,
+		100, 100, 0, '\t', DiscardEmptyColumns,
 		"a\vb\v\vd\n"
 			"a\vb\v\vd\ve\n"
 			"a\n"
@@ -541,7 +541,7 @@ var tests = []entry{
 
 	entry{
 		"16b debug",
-		100, 0, '\t', DiscardEmptyColumns | Debug,
+		100, 100, 0, '\t', DiscardEmptyColumns | Debug,
 		"a\vb\v\vd\n"
 			"a\vb\v\vd\ve\n"
 			"a\n"
@@ -557,7 +557,7 @@ var tests = []entry{
 
 	entry{
 		"16c",
-		100, 0, '\t', DiscardEmptyColumns,
+		100, 100, 0, '\t', DiscardEmptyColumns,
 		"a\tb\t\td\n"	// hard tabs - do not discard column
 			"a\tb\t\td\te\n"
 			"a\n"
@@ -573,7 +573,7 @@ var tests = []entry{
 
 	entry{
 		"16c debug",
-		100, 0, '\t', DiscardEmptyColumns | Debug,
+		100, 100, 0, '\t', DiscardEmptyColumns | Debug,
 		"a\tb\t\td\n"	// hard tabs - do not discard column
 			"a\tb\t\td\te\n"
 			"a\n"
@@ -591,6 +591,6 @@ var tests = []entry{
 
 func Test(t *testing.T) {
 	for _, e := range tests {
-		check(t, e.testname, e.tabwidth, e.padding, e.padchar, e.flags, e.src, e.expected)
+		check(t, e.testname, e.minwidth, e.tabwidth, e.padding, e.padchar, e.flags, e.src, e.expected)
 	}
 }