refactor roff rendering

runoff.go

@@ -7,91 +7,46 @@ import (
 	"io"
 	"strings"
 	"time"
-	"unicode"
 )
 
-func trim(s string) string {
-	return strings.TrimFunc(
-		s,
-		func(r rune) bool { return r != '\u00a0' && unicode.IsSpace(r) },
-	)
-}
-
-func textToString(t Txt) string {
-	if len(t.cat) == 0 && t.link == "" {
-		return trim(t.text)
-	}
-
-	if len(t.cat) == 0 && t.text == "" {
-		return trim(t.link)
-	}
-
-	if len(t.cat) == 0 {
-		return fmt.Sprintf("%s (%s)", t.text, t.link)
-	}
-
-	b := bytes.NewBuffer(nil)
-	for i := range t.cat {
-		if i > 0 {
-			b.WriteRune(' ')
-		}
-
-		b.WriteString(textToString(t.cat[i]))
-	}
-
-	return editString(b.String(), singleLine())
-}
-
 func manPageDate(d time.Time) string {
 	return fmt.Sprintf("%v %d", d.Month(), d.Year())
 }
 
-func roffString(s string, additionalEscape ...string) string {
-	s = editString(s, singleLine())
-	return editString(s, escapeRoff(additionalEscape...))
-}
-
-func renderRoffString(w writer, s string, additionalEscape ...string) {
-	s = roffString(s, additionalEscape...)
-	w.write(s)
+func roffTextToString(t Txt) string {
+	var b bytes.Buffer
+	renderRoffText(&b, t)
+	return b.String()
 }
 
 func roffDefinitionNames(d []DefinitionItem) []string {
 	var n []string
 	for _, di := range d {
-		n = append(n, textToString(di.name))
+		n = append(n, roffTextToString(di.name))
 	}
 
 	return n
 }
 
-func roffCellTexts(r []TableRow) ([][]string, error) {
+func roffCellTexts(r []TableRow) [][]string {
 	var cellTexts [][]string
 	for _, row := range r {
 		var c []string
 		for _, cell := range row.cells {
-			var b bytes.Buffer
-			w := newRoffWriter(&b, true)
-			renderRoffText(w, cell.text)
-			w.flush()
-			if w.err != nil {
-				return nil, w.err
-			}
-
-			c = append(c, b.String())
+			c = append(c, roffTextToString(cell.text))
 		}
 
 		cellTexts = append(cellTexts, c)
 	}
 
-	return cellTexts, nil
+	return cellTexts
 }
 
-func renderRoffText(w writer, text Txt, additionalEscape ...string) {
+func renderRoffText(w io.Writer, text Txt, additionalEscape ...string) {
 	if len(text.cat) > 0 {
 		for i, tc := range text.cat {
 			if i > 0 {
-				w.write(" ")
+				write(w, " ")
 			}
 
 			renderRoffText(w, tc)
@@ -101,34 +56,38 @@ func renderRoffText(w writer, text Txt, additionalEscape ...string) {
 	}
 
 	if text.bold {
-		w.write("\\fB")
+		write(w, "\\fB")
 	}
 
 	if text.italic {
-		w.write("\\fI")
+		write(w, "\\fI")
 	}
 
 	if text.bold || text.italic {
-		defer w.write("\\fR")
+		defer write(w, "\\fR")
 	}
 
-	if text.link != "" {
-		if text.text != "" {
-			renderRoffString(w, text.text, additionalEscape...)
-			w.write(" (")
-			renderRoffString(w, text.link, additionalEscape...)
-			w.write(")")
+	w, f := writeWith(w, singleLine(), escapeRoff(additionalEscape...))
+	if text.link == "" {
+		write(w, text.text)
+		f()
 		return
 	}
 
-		renderRoffString(w, text.link, additionalEscape...)
+	if text.text == "" {
+		write(w, text.link)
+		f()
 		return
 	}
 
-	renderRoffString(w, text.text, additionalEscape...)
+	write(w, text.text)
+	write(w, " (")
+	write(w, text.link)
+	write(w, ")")
+	f()
 }
 
-func renderRoffTitle(w writer, e Entry) {
+func renderRoffTitle(w io.Writer, e Entry) {
 	if e.titleLevel != 0 || e.man.section == 0 {
 		e.text.bold = true
 		p := Entry{
@@ -142,86 +101,92 @@ func renderRoffTitle(w writer, e Entry) {
 		return
 	}
 
-	w.write(".TH \"")
+	write(w, ".TH \"")
 	renderRoffText(w, e.text, "\"", "\\(dq")
-	w.write("\" ")
-	renderRoffString(w, fmt.Sprint(e.man.section), "\"", "\\(dq")
-	w.write(" \"")
+	write(w, "\" ")
+	w, f := writeWith(w, singleLine(), escapeRoff("\"", "\\(dq"))
+	write(w, fmt.Sprint(e.man.section))
+	w, _ = f()
+	write(w, " \"")
 	if !e.man.date.IsZero() {
-		w.write(manPageDate(e.man.date))
+		write(w, manPageDate(e.man.date))
 	}
 
-	w.write("\" \"")
-	renderRoffString(w, e.man.version, "\"", "\\(dq")
-	w.write("\" \"")
-	renderRoffString(w, e.man.category, "\"", "\\(dq")
-	w.write("\"")
+	write(w, "\" \"")
+	w, f = writeWith(w, singleLine(), escapeRoff("\"", "\\(dq"))
+	write(w, e.man.version)
+	w, _ = f()
+	write(w, "\" \"")
+	w, f = writeWith(w, singleLine(), escapeRoff("\"", "\\(dq"))
+	write(w, e.man.category)
+	w, _ = f()
+	write(w, "\"")
 }
 
-func renderRoffParagraph(w writer, e Entry) {
-	w.write(".in ", e.indent, "\n.ti ", e.indent+e.indentFirst, "\n")
+func renderRoffParagraph(w io.Writer, e Entry) {
+	write(w, ".in ", e.indent, "\n.ti ", e.indent+e.indentFirst, "\n")
 	renderRoffText(w, e.text)
 }
 
-func renderRoffList(w writer, e Entry) {
+func renderRoffList(w io.Writer, e Entry) {
 	for i, item := range e.items {
 		if i > 0 {
-			w.write("\n.br\n")
+			write(w, "\n.br\n")
 		}
 
-		w.write(".in ", e.indent+2, "\n.ti ", e.indent+e.indentFirst, "\n")
-		w.write("\\(bu ")
+		write(w, ".in ", e.indent+2, "\n.ti ", e.indent+e.indentFirst, "\n")
+		write(w, "\\(bu ")
 		renderRoffText(w, item.text)
 	}
 }
 
-func renderRoffNumberedList(w writer, e Entry) {
+func renderRoffNumberedList(w io.Writer, e Entry) {
 	maxDigits := numDigits(len(e.items))
 	for i, item := range e.items {
 		if i > 0 {
-			w.write("\n.br\n")
+			write(w, "\n.br\n")
 		}
 
-		w.write(".in ", e.indent+maxDigits+2, "\n.ti ", e.indent+e.indentFirst, "\n")
-		w.write(padRight(fmt.Sprintf("%d.", i+1), maxDigits+2))
+		write(w, ".in ", e.indent+maxDigits+2, "\n.ti ", e.indent+e.indentFirst, "\n")
+		write(w, padRight(fmt.Sprintf("%d.", i+1), maxDigits+2))
 		renderRoffText(w, item.text)
 	}
 }
 
-func renderRoffDefinitions(w writer, e Entry) {
+func renderRoffDefinitions(w io.Writer, e Entry) {
 	names := roffDefinitionNames(e.definitions)
 	maxNameLength := maxLength(names)
 	for i, definition := range e.definitions {
 		if i > 0 {
-			w.write("\n.br\n")
+			write(w, "\n.br\n")
 		}
 
-		w.write(".in ", e.indent+maxNameLength+4, "\n.ti ", e.indent+e.indentFirst, "\n")
-		w.write("\\(bu ")
+		write(w, ".in ", e.indent+maxNameLength+4, "\n.ti ", e.indent+e.indentFirst, "\n")
+		write(w, "\\(bu ")
 		renderRoffText(w, definition.name)
-		w.write(":", timesn("\\~", maxNameLength-len([]rune(names[i]))+1))
+		write(w, ":", timesn("\\~", maxNameLength-len([]rune(names[i]))+1))
 		renderRoffText(w, definition.value)
 	}
 }
 
-func renderRoffNumberedDefinitions(w writer, e Entry) {
+func renderRoffNumberedDefinitions(w io.Writer, e Entry) {
 	maxDigits := numDigits(len(e.definitions))
 	names := roffDefinitionNames(e.definitions)
 	maxNameLength := maxLength(names)
 	for i, definition := range e.definitions {
 		if i > 0 {
-			w.write("\n.br\n")
+			write(w, "\n.br\n")
 		}
 
-		w.write(".in ", e.indent+maxDigits+maxNameLength+4, "\n.ti ", e.indent+e.indentFirst, "\n")
-		w.write(padRight(fmt.Sprintf("%d.", i+1), maxDigits+2))
+		write(w, ".in ", e.indent+maxDigits+maxNameLength+4, "\n.ti ", e.indent+e.indentFirst, "\n")
+		write(w, padRight(fmt.Sprintf("%d.", i+1), maxDigits+2))
 		renderRoffText(w, definition.name)
-		w.write(":", timesn("\\~", maxNameLength-len([]rune(names[i]))+1))
+		write(w, ":", timesn("\\~", maxNameLength-len([]rune(names[i]))+1))
 		renderRoffText(w, definition.value)
 	}
 }
 
-func renderRoffTable(w writer, e Entry) {
+func renderRoffTable(w io.Writer, e Entry) {
 	if len(e.rows) == 0 {
 		return
 	}
@@ -231,14 +196,10 @@ func renderRoffTable(w writer, e Entry) {
 		return
 	}
 
-	w.write(".nf\n")
-	defer w.write("\n.fi")
-
-	cellTexts, err := roffCellTexts(e.rows)
-	if err != nil {
-		w.setErr(err)
-	}
+	write(w, ".nf\n")
+	defer write(w, "\n.fi")
 
+	cellTexts := roffCellTexts(e.rows)
 	totalSeparatorWidth := (len(cellTexts[0]) - 1) * 3
 	if e.wrapWidth > 0 {
 		allocatedWidth := e.wrapWidth - e.indent - totalSeparatorWidth
@@ -257,6 +218,7 @@ func renderRoffTable(w writer, e Entry) {
 		totalWidth += columnWidths[i]
 	}
 
+	w, f := writeWith(w, indent(e.indent, e.indent))
 	hasHeader := e.rows[0].header
 	for i := range cellTexts {
 		if i > 0 {
@@ -265,9 +227,9 @@ func renderRoffTable(w writer, e Entry) {
 				sep = "="
 			}
 
-			w.write("\n")
-			w.write(timesn(" ", e.indent), timesn(sep, totalWidth))
-			w.write("\n")
+			write(w, "\n")
+			write(w, timesn(sep, totalWidth))
+			write(w, "\n")
 		}
 
 		lines := make([][]string, len(cellTexts[i]))
@@ -284,14 +246,12 @@ func renderRoffTable(w writer, e Entry) {
 
 		for k := 0; k < maxLines; k++ {
 			if k > 0 {
-				w.write("\n")
+				write(w, "\n")
 			}
 
 			for j := range lines {
-				if j == 0 {
-					w.write(timesn(" ", e.indent))
-				} else {
-					w.write(" | ")
+				if j > 0 {
+					write(w, " | ")
 				}
 
 				var l string
@@ -299,57 +259,59 @@ func renderRoffTable(w writer, e Entry) {
 					l = lines[j][k]
 				}
 
-				w.write(padRight(l, columnWidths[j]))
+				write(w, padRight(l, columnWidths[j]))
 			}
 		}
 	}
 
 	if hasHeader && len(cellTexts) == 1 {
-		w.write("\n", timesn("=", totalWidth))
-	}
+		write(w, "\n", timesn("=", totalWidth))
 	}
 
-func renderRoffCode(w writer, e Entry) {
-	w.write(".nf\n")
-	defer w.write("\n.fi")
-	txt := editString(e.text.text, escapeRoff())
-	txt = editString(txt, indent(e.indent, e.indent))
-	w.write(txt)
+	f()
 }
 
-func renderRoffMultiple(w writer, s SyntaxItem) {
+func renderRoffCode(w io.Writer, e Entry) {
+	write(w, ".nf\n")
+	defer write(w, "\n.fi")
+	w, f := writeWith(w, escapeRoff(), indent(e.indent, e.indent))
+	write(w, e.text.text)
+	f()
+}
+
+func renderRoffMultiple(w io.Writer, s SyntaxItem) {
 	s.topLevel = false
 	s.multiple = false
 	renderRoffSyntaxItem(w, s)
-	w.write("...")
+	write(w, "...")
 }
 
-func renderRoffRequired(w writer, s SyntaxItem) {
+func renderRoffRequired(w io.Writer, s SyntaxItem) {
 	s.delimited = true
 	s.topLevel = false
 	s.required = false
-	w.write("<")
+	write(w, "<")
 	renderRoffSyntaxItem(w, s)
-	w.write(">")
+	write(w, ">")
 }
 
-func renderRoffOptional(w writer, s SyntaxItem) {
+func renderRoffOptional(w io.Writer, s SyntaxItem) {
 	s.delimited = true
 	s.topLevel = false
 	s.optional = false
-	w.write("[")
+	write(w, "[")
 	renderRoffSyntaxItem(w, s)
-	w.write("]")
+	write(w, "]")
 }
 
-func renderRoffSequence(w writer, s SyntaxItem) {
+func renderRoffSequence(w io.Writer, s SyntaxItem) {
 	if !s.delimited && !s.topLevel {
-		w.write("(")
+		write(w, "(")
 	}
 
 	for i, item := range s.sequence {
 		if i > 0 {
-			w.write(" ")
+			write(w, " ")
 		}
 
 		item.delimited = false
@@ -357,13 +319,13 @@ func renderRoffSequence(w writer, s SyntaxItem) {
 	}
 
 	if !s.delimited && !s.topLevel {
-		w.write(")")
+		write(w, ")")
 	}
 }
 
-func renderRoffChoice(w writer, s SyntaxItem) {
+func renderRoffChoice(w io.Writer, s SyntaxItem) {
 	if !s.delimited && !s.topLevel {
-		w.write("(")
+		write(w, "(")
 	}
 
 	for i, item := range s.choice {
@@ -373,7 +335,7 @@ func renderRoffChoice(w writer, s SyntaxItem) {
 				separator = "\n"
 			}
 
-			w.write(separator)
+			write(w, separator)
 		}
 
 		item.delimited = false
@@ -381,15 +343,15 @@ func renderRoffChoice(w writer, s SyntaxItem) {
 	}
 
 	if !s.delimited && !s.topLevel {
-		w.write(")")
+		write(w, ")")
 	}
 }
 
-func renderRoffSymbol(w writer, s SyntaxItem) {
-	w.write(editString(s.symbol, escapeRoff()))
+func renderRoffSymbol(w io.Writer, s SyntaxItem) {
+	write(w, s.symbol)
 }
 
-func renderRoffSyntaxItem(w writer, s SyntaxItem) {
+func renderRoffSyntaxItem(w io.Writer, s SyntaxItem) {
 	switch {
 
 	// foo...
@@ -418,24 +380,21 @@ func renderRoffSyntaxItem(w writer, s SyntaxItem) {
 	}
 }
 
-func renderRoffSyntax(w writer, e Entry) {
+func renderRoffSyntax(w io.Writer, e Entry) {
 	s := e.syntax
 	s.topLevel = true
-	w.write(".nf\n")
-	defer w.write("\n.fi")
-	w.write(timesn("\u00a0", e.indent))
+	write(w, ".nf\n")
+	defer write(w, "\n.fi")
+	w, f := writeWith(w, escapeRoff(), indent(e.indent, e.indent))
 	renderRoffSyntaxItem(w, s)
+	f()
 }
 
 func renderRoff(out io.Writer, d Document) error {
-	w := newRoffWriter(out, false)
+	w, f := writeWith(out, roffNBSP(), errorHandler)
 	for i, e := range d.entries {
-		if err := w.error(); err != nil {
-			return err
-		}
-
 		if i > 0 {
-			w.write("\n.br\n.sp 1v\n")
+			write(w, "\n.br\n.sp 1v\n")
 		}
 
 		switch e.typ {
@@ -463,9 +422,9 @@ func renderRoff(out io.Writer, d Document) error {
 	}
 
 	if len(d.entries) > 0 {
-		w.write("\n")
+		write(w, "\n")
 	}
 
-	w.flush()
-	return w.err
+	_, err := f()
+	return err
 }

runoff_test.go

@@ -127,7 +127,7 @@ Below you can find some test text, with various text items.
 .br
 .sp 1v
 .nf
-\~\~\~\~\~\~\~\~textfmt.Doc ( [Entry]... )
+        textfmt.Doc ( [Entry]... )
 .fi
 .br
 .sp 1v
@@ -329,7 +329,7 @@ Below you can find some test text, with various text items.
 .br
 .sp 1v
 .nf
-\~\~\~\~\~\~\~\~textfmt.Doc ( [Entry]... )
+        textfmt.Doc ( [Entry]... )
 .fi
 .br
 .sp 1v
@@ -2292,7 +2292,7 @@ and silver birch\~\~\~\~ | their canopies creating\~ | and shadow on the
 				t.Fatal(err)
 			}
 
-			if b.String() != ".nf\n\\~\\~\\~\\~foo [options]... <filename> [string|number]...\n.fi\n" {
+			if b.String() != ".nf\n    foo [options]... <filename> [string|number]...\n.fi\n" {
 				t.Fatal(b.String())
 			}
 		})

teletype.go

@@ -149,8 +149,7 @@ func ttyCellTexts(rows []TableRow) [][]string {
 	for _, row := range rows {
 		var c []string
 		for _, cell := range row.cells {
-			txt := ttyTextToString(cell.text)
-			c = append(c, txt)
+			c = append(c, ttyTextToString(cell.text))
 		}
 
 		cellTexts = append(cellTexts, c)