no screaming case

Makefile

@@ -1,17 +1,17 @@
-SOURCES = $(shell find . -name "*.go")
+sources = $(shell find . -name "*.go")
 
 default: build
 
-build: $(SOURCES)
+build: $(sources)
 	go build
 
-fmt: $(SOURCES)
+fmt: $(sources)
 	go fmt
 
-check: $(SOURCES)
+check: $(sources)
 	go test -count 1
 
-.cover: $(SOURCES)
+.cover: $(sources)
 	go test -count 1 -coverprofile .cover
 
 cover: .cover

escape.go

@@ -0,0 +1,72 @@
+package textfmt
+
+import "fmt"
+
+type escapeRange struct {
+	from, to    rune
+	replacement string
+}
+
+type escape[S any] struct {
+	out               writer
+	state             S
+	escape            map[rune]string
+	escapeRanges      []escapeRange
+	conditionalEscape map[rune]func(S, rune) (string, bool)
+	updateState       func(S, rune) S
+}
+
+func (e *escape[S]) inEscapeRange(r rune) (string, bool) {
+	for _, rng := range e.escapeRanges {
+		if r >= rng.from && r <= rng.to {
+			return rng.replacement, true
+		}
+	}
+
+	return "", false
+}
+
+func (e *escape[S]) write(a ...any) {
+	for _, ai := range a {
+		s := fmt.Sprint(ai)
+		r := []rune(s)
+		for _, ri := range r {
+			var (
+				output string
+				found  bool
+			)
+
+			output, found = e.escape[ri]
+			if !found {
+				output, found = e.inEscapeRange(ri)
+			}
+
+			if !found {
+				conditional := e.conditionalEscape[ri]
+				if conditional != nil {
+					output, found = conditional(e.state, ri)
+				}
+			}
+
+			if !found {
+				output = string(ri)
+			}
+
+			e.out.write(output)
+			if e.updateState != nil {
+				e.state = e.updateState(e.state, ri)
+			}
+		}
+	}
+}
+
+func (e *escape[S]) flush() {
+	e.out.flush()
+}
+
+func (e *escape[S]) error() error {
+	return e.out.error()
+}
+
+func (e *escape[S]) setErr(err error) {
+}

indent.go

@@ -0,0 +1,82 @@
+package textfmt
+
+import (
+	"fmt"
+	"unicode"
+)
+
+type indent struct {
+	out                 writer
+	firstIndent, indent int
+	firstWidth, width   int
+	currentLineLength   int
+	currentWord         []rune
+	multiline           bool
+}
+
+func (i *indent) write(a ...any) {
+	for _, ai := range a {
+		s := fmt.Sprint(ai)
+		r := []rune(s)
+		for _, ri := range r {
+			width := i.width
+			if !i.multiline {
+				width = i.firstWidth
+			}
+
+			indent := i.indent
+			if !i.multiline {
+				indent = i.firstIndent
+			}
+
+			if !unicode.IsSpace(ri) || ri == '\u00a0' {
+				i.currentWord = append(i.currentWord, ri)
+				continue
+			}
+
+			nonWrapNewline := width == 0 && ri == '\n'
+			if len(i.currentWord) == 0 && !nonWrapNewline {
+				continue
+			}
+
+			nextLineLength := i.currentLineLength + len(i.currentWord) + 1
+			if i.currentLineLength > 0 && width > 0 && nextLineLength > width {
+				i.out.write("\n")
+				i.currentLineLength = 0
+				i.multiline = true
+			}
+
+			if i.currentLineLength > 0 && len(i.currentWord) > 0 {
+				i.out.write(" ")
+				i.currentLineLength++
+			}
+
+			if i.currentLineLength == 0 && len(i.currentWord) > 0 {
+				i.out.write(timesn(" ", indent))
+				i.currentLineLength += indent
+			}
+
+			if len(i.currentWord) > 0 {
+				i.out.write(string(i.currentWord))
+				i.currentLineLength += len(i.currentWord)
+				i.currentWord = nil
+			}
+
+			if nonWrapNewline {
+				i.out.write("\n")
+				i.currentLineLength = 0
+			}
+		}
+	}
+}
+
+func (i *indent) flush() {
+	i.out.flush()
+}
+
+func (i *indent) error() error {
+	return i.out.error()
+}
+
+func (e *indent) setErr(err error) {
+}

markdown.go

@@ -5,11 +5,98 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"slices"
 	"strings"
 )
 
-func escapeMarkdown(s string, additional ...rune) string {
+type mdEscapeState struct {
+	newLine         bool
+	numberOnNewLine bool
+	linkValue       bool
+	linkClosed      bool
+	linkOpen        bool
+}
+
+func updateMDEscapeState(s mdEscapeState, r rune) mdEscapeState {
+	return mdEscapeState{
+		numberOnNewLine: (s.newLine || s.numberOnNewLine) && r >= '0' && r <= '9',
+		newLine:         r == '\n',
+		linkValue:       s.linkClosed && r == '(' || s.linkValue && r != ')',
+		linkClosed:      s.linkOpen && r == ']',
+		linkOpen:        !s.linkValue && r == '[' || s.linkOpen && r != ']',
+	}
+}
+
+func escapeMarkdown(out writer, additional ...rune) writer {
+	esc := map[rune]string{
+		'\\': "\\\\",
+		'`':  "\\`",
+		'*':  "\\*",
+		'_':  "\\_",
+		'[':  "\\[",
+		']':  "\\]",
+		'#':  "\\#",
+		'<':  "\\<",
+		'>':  "\\>",
+	}
+
+	for _, a := range additional {
+		esc[a] = string([]rune{'\\', a})
+	}
+
+	return &escape[mdEscapeState]{
+		out: out,
+		state: mdEscapeState{
+			newLine: true,
+		},
+		escape: esc,
+		conditionalEscape: map[rune]func(mdEscapeState, rune) (string, bool){
+			'+': func(s mdEscapeState, _ rune) (string, bool) {
+				if s.newLine {
+					return "\\+", true
+				}
+
+				return "", false
+			},
+			'-': func(s mdEscapeState, _ rune) (string, bool) {
+				if s.newLine {
+					return "\\-", true
+				}
+
+				return "", false
+			},
+			'.': func(s mdEscapeState, _ rune) (string, bool) {
+				if s.numberOnNewLine {
+					return "\\.", true
+				}
+
+				return "", false
+			},
+			'(': func(s mdEscapeState, _ rune) (string, bool) {
+				if s.linkClosed {
+					return "\\(", true
+				}
+
+				return "", false
+			},
+			')': func(s mdEscapeState, _ rune) (string, bool) {
+				if s.linkValue {
+					return "\\)", true
+				}
+
+				return "", false
+			},
+		},
+		updateState: updateMDEscapeState,
+	}
+}
+
+func escapeMarkdownPrev(s string, additional ...rune) string {
+	var b bytes.Buffer
+	w := &textWriter{out: &b}
+	e := escapeMarkdown(w, additional...)
+	e.write(s)
+	return b.String()
+	/*
 		var (
 			rr                                    []rune
 			isNumberOnNewLine                     bool
@@ -69,6 +156,7 @@ func escapeMarkdown(s string, additional ...rune) string {
 		}
 
 		return string(rr)
+	*/
 }
 
 func mdTextToString(text Txt) (string, error) {
@@ -128,9 +216,9 @@ func renderMDText(w writer, text Txt) {
 	}
 
 	text.text = singleLine(text.text)
-	text.text = escapeMarkdown(text.text)
+	text.text = escapeMarkdownPrev(text.text)
 	text.link = singleLine(text.link)
-	text.link = escapeMarkdown(text.link)
+	text.link = escapeMarkdownPrev(text.link)
 	if text.bold {
 		w.write("**")
 	}
@@ -381,7 +469,7 @@ func renderMDChoice(w writer, s SyntaxItem) {
 }
 
 func renderMDSymbol(w writer, s SyntaxItem) {
-	w.write(escapeTeletype(s.symbol))
+	w.write(escapeMarkdownPrev(s.symbol))
 }
 
 func renderMDSyntaxItem(w writer, s SyntaxItem) {

notes.txt

@@ -2,4 +2,40 @@ indentation for syntax in tty and roff
 does the table need the non-breaking space for the filling in roff?
 indentation for syntax may not require non-break spaces
 test empty cat
-show top level choice on separate lines in the same block
+improve wrapping of list paragraphs by allowing different first line wrap
+there should be no errors other than actual IO
+
+[refactor]
+stop on errors earlier where possible
+denormalize individual render functions
+support single line in indent, indentOnly option
+escape is more generic than editor:
+- could replace editor
+- maybe indent, too
+- could become its own library
+- could be used in HTML, too
+collect the common transformations:
+- escape
+- wrap
+- collapse to single line
+- fill spaces
+- convert spaces
+- width and height calculations
+- ...
+identify the order of these transformations while rendering the different entries:
+- tty:
+	- title
+	- paragraph
+	- ...
+- roff:
+	- title
+	- paragraph
+	- ...
+- md:
+	- title
+	- paragraph
+	- ...
+- html:
+	- title
+	- paragraph
+	- ...

runoff.go

@@ -9,7 +9,61 @@ import (
 	"time"
 )
 
-func escapeRoff(s string, additional ...string) string {
+type lineStarted bool
+
+func isNewLine(replacement string) func(lineStarted, rune) (string, bool) {
+	return func(ls lineStarted, r rune) (string, bool) {
+		if ls {
+			return string(r), false
+		}
+
+		return replacement, true
+	}
+}
+
+func updateLineStarted(_ lineStarted, r rune) lineStarted {
+	return r != '\n'
+}
+
+func escapeRoff(out writer, additional ...string) writer {
+	const invalidAdditional = "invalid additional escape definition"
+
+	if len(additional)%2 != 0 {
+		panic(errors.New(invalidAdditional))
+	}
+
+	esc := map[rune]string{
+		'\\':     "\\\\",
+		'\u00a0': "\\~",
+	}
+
+	for i := 0; i > len(additional); i += 2 {
+		r := []rune(additional[i])
+		if len(r) != 1 {
+			panic(errors.New(invalidAdditional))
+		}
+
+		esc[r[0]] = additional[i+1]
+	}
+
+	return &escape[lineStarted]{
+		out:    out,
+		escape: esc,
+		conditionalEscape: map[rune]func(lineStarted, rune) (string, bool){
+			'.':  isNewLine("\\&."),
+			'\'': isNewLine("\\&'"),
+		},
+		updateState: updateLineStarted,
+	}
+}
+
+func escapeRoffPrev(s string, additional ...string) string {
+	var b bytes.Buffer
+	w := &textWriter{out: &b}
+	e := escapeRoff(w, additional...)
+	e.write(s)
+	return b.String()
+	/*
 	const invalidAdditional = "invalid additional escape definition"
 
 	var (
@@ -75,6 +129,7 @@ func escapeRoff(s string, additional ...string) string {
 	}
 
 	return string(e)
+	*/
 }
 
 func manPageDate(d time.Time) string {
@@ -83,7 +138,7 @@ func manPageDate(d time.Time) string {
 
 func roffString(s string, additionalEscape ...string) string {
 	s = singleLine(s)
-	return escapeRoff(s, additionalEscape...)
+	return escapeRoffPrev(s, additionalEscape...)
 }
 
 func renderRoffString(w writer, s string, additionalEscape ...string) {
@@ -341,7 +396,7 @@ func renderRoffTable(w writer, e Entry) {
 func renderRoffCode(w writer, e Entry) {
 	w.write(".nf\n")
 	defer w.write("\n.fi")
-	e.text.text = escapeRoff(e.text.text)
+	e.text.text = escapeRoffPrev(e.text.text)
 	writeLines(w, e.text.text, e.indent, e.indent)
 }
 
@@ -414,7 +469,7 @@ func renderRoffChoice(w writer, s SyntaxItem) {
 }
 
 func renderRoffSymbol(w writer, s SyntaxItem) {
-	w.write(escapeRoff(s.symbol))
+	w.write(escapeRoffPrev(s.symbol))
 }
 
 func renderRoffSyntaxItem(w writer, s SyntaxItem) {

teletype.go

@@ -8,7 +8,32 @@ import (
 	"strings"
 )
 
-func escapeTeletype(s string) string {
+func escapeTeletype(out writer) writer {
+	return &escape[struct{}]{
+		out: out,
+		escapeRanges: []escapeRange{{
+			from:        0x00,
+			to:          '\t' - 1,
+			replacement: "\u00b7",
+		}, {
+			from:        '\n' + 1,
+			to:          0x1f,
+			replacement: "\u00b7",
+		}, {
+			from:        0x7f,
+			to:          0x9f,
+			replacement: "\u00b7",
+		}},
+	}
+}
+
+func escapeTeletypePrev(s string) string {
+	var b bytes.Buffer
+	w := &textWriter{out: &b}
+	e := escapeTeletype(w)
+	e.write(s)
+	return b.String()
+	/*
 	r := []rune(s)
 	for i := range r {
 		if r[i] >= 0x00 && r[i] <= 0x1f && r[i] != '\n' && r[i] != '\t' {
@@ -21,6 +46,7 @@ func escapeTeletype(s string) string {
 	}
 
 	return string(r)
+	*/
 }
 
 func ttyTextToString(text Txt) (string, error) {
@@ -62,9 +88,9 @@ func renderTTYText(w writer, text Txt) {
 	}
 
 	text.text = singleLine(text.text)
-	text.text = escapeTeletype(text.text)
+	text.text = escapeTeletypePrev(text.text)
 	text.link = singleLine(text.link)
-	text.link = escapeTeletype(text.link)
+	text.link = escapeTeletypePrev(text.link)
 	if text.link != "" {
 		if text.text != "" {
 			w.write(text.text)
@@ -282,7 +308,7 @@ func renderTTYTable(w writer, e Entry) {
 }
 
 func renderTTYCode(w writer, e Entry) {
-	e.text.text = escapeTeletype(e.text.text)
+	e.text.text = escapeTeletypePrev(e.text.text)
 	writeLines(w, e.text.text, e.indent, e.indent)
 }
 
@@ -355,7 +381,7 @@ func renderTTYChoice(w writer, s SyntaxItem) {
 }
 
 func renderTTYSymbol(w writer, s SyntaxItem) {
-	w.write(escapeTeletype(s.symbol))
+	w.write(escapeTeletypePrev(s.symbol))
 }
 
 func renderTTYSyntaxItem(w writer, s SyntaxItem) {
@@ -395,7 +421,14 @@ func renderTTYSyntax(w writer, e Entry) {
 }
 
 func renderTeletype(out io.Writer, d Document) error {
-	w := ttyWriter{w: out}
+	tw := &textWriter{out: out}
+	w := &editor{
+		out: tw,
+		replace: map[string]string{
+			"\u00a0": " ",
+		},
+	}
+
 	for i, e := range d.entries {
 		if i > 0 {
 			w.write("\n\n")
@@ -403,23 +436,23 @@ func renderTeletype(out io.Writer, d Document) error {
 
 		switch e.typ {
 		case title:
-			renderTTYTitle(&w, e)
+			renderTTYTitle(w, e)
 		case paragraph:
-			renderTTYParagraph(&w, e)
+			renderTTYParagraph(w, e)
 		case list:
-			renderTTYList(&w, e)
+			renderTTYList(w, e)
 		case numberedList:
-			renderTTYNumberedList(&w, e)
+			renderTTYNumberedList(w, e)
 		case definitions:
-			renderTTYDefinitions(&w, e)
+			renderTTYDefinitions(w, e)
 		case numberedDefinitions:
-			renderTTYNumberedDefinitions(&w, e)
+			renderTTYNumberedDefinitions(w, e)
 		case table:
-			renderTTYTable(&w, e)
+			renderTTYTable(w, e)
 		case code:
-			renderTTYCode(&w, e)
+			renderTTYCode(w, e)
 		case syntax:
-			renderTTYSyntax(&w, e)
+			renderTTYSyntax(w, e)
 		default:
 			return errors.New("invalid entry")
 		}
@@ -429,5 +462,5 @@ func renderTeletype(out io.Writer, d Document) error {
 		w.write("\n")
 	}
 
-	return w.err
+	return w.error()
 }

write.go

@@ -3,15 +3,99 @@ package textfmt
 import (
 	"fmt"
 	"io"
+	"slices"
 	"strings"
 )
 
 type writer interface {
 	write(...any)
+	flush()
 	error() error
-	setErr(error)
+	setErr(err error) // TODO: remove
 }
 
+type textWriter struct {
+	err error
+	out io.Writer
+}
+
+type editor struct {
+	out     writer
+	pending []rune
+	replace map[string]string
+}
+
+func (w *textWriter) write(a ...any) {
+	if w.err != nil {
+		return
+	}
+
+	for _, ai := range a {
+		if _, err := w.out.Write([]byte(fmt.Sprint(ai))); err != nil {
+			w.err = err
+			return
+		}
+	}
+}
+
+func (w *textWriter) flush() {}
+
+func (w *textWriter) error() error {
+	return w.err
+}
+
+func (e *textWriter) setErr(err error) {
+}
+
+func (e *editor) write(a ...any) {
+	for _, ai := range a {
+		s := fmt.Sprint(ai)
+		r := []rune(s)
+		for key, replacement := range e.replace {
+			rk := []rune(key)
+			if len(e.pending) >= len(rk) {
+				continue
+			}
+
+			if !slices.Equal(e.pending, rk[:len(e.pending)]) {
+				continue
+			}
+
+			if len(r) < len(rk)-len(e.pending) {
+				if slices.Equal(r, rk[len(e.pending):len(e.pending)+len(r)]) {
+					e.pending = append(e.pending, r...)
+					r = nil
+					break
+				}
+
+				continue
+			}
+
+			if slices.Equal(r[:len(rk)-len(e.pending)], rk[len(e.pending):]) {
+				r = []rune(replacement)
+				e.pending = nil
+				break
+			}
+		}
+
+		e.out.write(string(r))
+	}
+}
+
+func (e *editor) flush() {
+	e.out.write(string(e.pending))
+	e.out.flush()
+}
+
+func (e *editor) error() error {
+	return e.out.error()
+}
+
+func (e *editor) setErr(err error) {
+}
+
+// --
+
 type ttyWriter struct {
 	w        io.Writer
 	internal bool
@@ -52,6 +136,8 @@ func (w *ttyWriter) write(a ...any) {
 	}
 }
 
+func (w *ttyWriter) flush() {}
+
 func (w *ttyWriter) error() error {
 	return w.err
 }
@@ -88,6 +174,8 @@ func (w *roffWriter) write(a ...any) {
 	}
 }
 
+func (w *roffWriter) flush() {}
+
 func (w *roffWriter) error() error {
 	return w.err
 }
@@ -117,6 +205,8 @@ func (w *mdWriter) write(a ...any) {
 	}
 }
 
+func (w *mdWriter) flush() {}
+
 func (w *mdWriter) error() error {
 	return w.err
 }