diff options
| -rw-r--r-- | src/pkg/tabwriter/tabwriter.go | 36 | ||||
| -rw-r--r-- | src/pkg/tabwriter/tabwriter_test.go | 35 |
2 files changed, 53 insertions, 18 deletions
diff --git a/src/pkg/tabwriter/tabwriter.go b/src/pkg/tabwriter/tabwriter.go index 5103f6ce2..15ffc79cc 100644 --- a/src/pkg/tabwriter/tabwriter.go +++ b/src/pkg/tabwriter/tabwriter.go @@ -23,11 +23,13 @@ import ( // A cell represents a segment of text delineated by tabs, form-feed, // or newline chars. The text itself is stored in a separate buffer; -// cell only describes the segment's size in bytes and width in runes. +// 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. // type cell struct { size int; // cell size in bytes width int; // cell width in runes + htab bool; // true if the cell is terminated by an htab ('\t') } @@ -43,6 +45,12 @@ type cell struct { // not tab-separated: trailing non-tab text at the end of a line // is not part of any 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 +// this flag. +// // The Writer assumes that all characters have the same width; // this may not be true in some fonts, especially with certain // UTF-8 characters. @@ -314,16 +322,19 @@ func (b *Writer) format(pos0 int, line0, line1 int) (pos int, err os.Error) { // column block begin width := b.cellwidth; // minimal column width - wsum := 0; // the sum of all unpadded cell widths in this column + discardable := true; // true if all cells in this column are empty and "soft" for ; this < line1; this++ { line = b.line(this); if column < line.Len() - 1 { // cell exists in this column - w := line.At(column).(cell).width; - wsum += w; + c := line.At(column).(cell); // update width - if t := w + b.padding; t > width { - width = t; + if w := c.width + b.padding; w > width { + width = w; + } + // update discardable + if c.width > 0 || c.htab { + discardable = false; } } else { break @@ -332,7 +343,7 @@ func (b *Writer) format(pos0 int, line0, line1 int) (pos int, err os.Error) { // column block end // discard empty columns if necessary - if wsum == 0 && b.flags & DiscardEmptyColumns != 0 { + if discardable && b.flags & DiscardEmptyColumns != 0 { width = 0; } @@ -391,7 +402,8 @@ func (b *Writer) terminateHTML() { // Terminate the current cell by adding it to the list of cells of the // current line. Returns the number of cells in that line. // -func (b *Writer) terminateCell() int { +func (b *Writer) terminateCell(htab bool) int { + b.cell.htab = htab; line := b.line(b.lines.Len() - 1); line.Push(b.cell); b.cell = cell{}; @@ -411,7 +423,7 @@ func (b *Writer) Flush() os.Error { // inside html tag/entity - terminate it even if incomplete b.terminateHTML(); } - b.terminateCell(); + b.terminateCell(false); } // format contents of buffer @@ -435,12 +447,12 @@ func (b *Writer) Write(buf []byte) (written int, err os.Error) { if b.html_char == 0 { // outside html tag/entity switch ch { - case '\t', '\n', '\f': + case '\t', '\v', '\n', '\f': // end of cell b.append(buf[i0 : i], true); i0 = i+1; // exclude ch from (next) cell - ncells := b.terminateCell(); - if ch != '\t' { + ncells := b.terminateCell(ch == '\t'); + if ch == '\n' || ch == '\f' { // terminate line b.addLine(); if ch == '\f' || ncells == 1 { diff --git a/src/pkg/tabwriter/tabwriter_test.go b/src/pkg/tabwriter/tabwriter_test.go index 6b2fa862e..b43a26980 100644 --- a/src/pkg/tabwriter/tabwriter_test.go +++ b/src/pkg/tabwriter/tabwriter_test.go @@ -418,14 +418,21 @@ var tests = []entry { entry{ "15b", 4, 0, '.', DiscardEmptyColumns, - "a\t\tb", - "a...b" + "a\t\tb", // htabs - do not discard column + "a.......b" }, entry{ "15c", + 4, 0, '.', DiscardEmptyColumns, + "a\v\vb", + "a...b" + }, + + entry{ + "15d", 4, 0, '.', AlignRight | DiscardEmptyColumns, - "a\t\tb", + "a\v\vb", "...ab" }, @@ -448,14 +455,30 @@ var tests = []entry { entry{ "16b", 100, 0, '\t', DiscardEmptyColumns, - "a\tb\t\td\n" + "a\vb\v\vd\n" + "a\vb\v\vd\ve\n" + "a\n" + "a\vb\vc\vd\n" + "a\vb\vc\vd\ve\n", + + "a\tb\td\n" + "a\tb\td\te\n" + "a\n" + "a\tb\tc\td\n" + "a\tb\tc\td\te\n" + }, + + entry{ + "16c", + 100, 0, '\t', DiscardEmptyColumns, + "a\tb\t\td\n" // hard tabs - do not discard column "a\tb\t\td\te\n" "a\n" "a\tb\tc\td\n" "a\tb\tc\td\te\n", - "a\tb\td\n" - "a\tb\td\te\n" + "a\tb\t\td\n" + "a\tb\t\td\te\n" "a\n" "a\tb\tc\td\n" "a\tb\tc\td\te\n" |