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-rw-r--r--filters/wrap.go267
1 files changed, 0 insertions, 267 deletions
diff --git a/filters/wrap.go b/filters/wrap.go
deleted file mode 100644
index ea5186d4..00000000
--- a/filters/wrap.go
+++ /dev/null
@@ -1,267 +0,0 @@
-package main
-
-import (
- "bufio"
- "errors"
- "flag"
- "fmt"
- "io"
- "os"
- "regexp"
- "strings"
-
- "github.com/mattn/go-runewidth"
-)
-
-type paragraph struct {
- // email quote prefix, if any
- quotes string
- // list item indent, if any
- leader string
- // actual text of this paragraph
- text string
- // percentage of letters in text
- proseRatio int
- // text ends with a space
- flowed bool
- // paragraph is a list item
- listItem bool
-}
-
-func main() {
- var err error
- var width int
- var reflow bool
- var file string
- var proseRatio int
- var input *os.File
-
- fs := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
- fs.IntVar(&width, "w", 80, "preferred wrap margin")
- fs.BoolVar(&reflow, "r", false,
- "reflow all paragraphs even if no trailing space")
- fs.IntVar(&proseRatio, "l", 50,
- "minimum percentage of letters in a line to be considered a paragaph")
- fs.StringVar(&file, "f", "", "read from file instead of stdin")
- _ = fs.Parse(os.Args[1:])
-
- if file != "" {
- input, err = os.OpenFile(file, os.O_RDONLY, 0o644)
- if err != nil {
- goto end
- }
- } else {
- input = os.Stdin
- }
-
- err = wrap(input, os.Stdout, width, reflow, proseRatio)
-
-end:
- if err != nil && !errors.Is(err, io.EOF) {
- fmt.Fprintf(os.Stderr, "error: %s\n", err)
- os.Exit(1)
- }
-}
-
-func wrap(
- in io.Reader, out io.Writer, width int, reflow bool, proseRatio int,
-) error {
- var para *paragraph = nil
- var line string
- var err error
-
- if patchSubjectRe.MatchString(os.Getenv("AERC_SUBJECT")) {
- // never reflow patches
- _, err = io.Copy(out, in)
- } else {
- reader := bufio.NewReader(in)
- line, err = reader.ReadString('\n')
- for ; err == nil; line, err = reader.ReadString('\n') {
- next := parse(line)
- switch {
- case para == nil:
- para = next
- case para.isContinuation(next, reflow, proseRatio):
- para.join(next)
- default:
- para.write(out, width, proseRatio)
- para = next
- }
- }
- if para != nil {
- para.write(out, width, proseRatio)
- }
- }
-
- return err
-}
-
-// Parse a line of text into a paragraph structure
-func parse(line string) *paragraph {
- p := new(paragraph)
- q := 0
- t := 0
- line = strings.TrimRight(line, "\r\n")
- // tabs cause a whole lot of troubles, replace them with 8 spaces
- line = strings.ReplaceAll(line, "\t", " ")
-
- // Use integer offsets to find relevant positions in the line
- //
- // > > > 2) blah blah blah blah
- // ^--------+-----^
- // q | t
- // end of quotes | start of text
- // |
- // list item leader
-
- // detect the end of quotes prefix if any
- for q < len(line) && line[q] == '>' {
- q += 1
- if q < len(line) && line[q] == ' ' {
- q += 1
- }
- }
-
- // detect list item leader
- loc := listItemRe.FindStringIndex(line[q:])
- if loc != nil {
- // start of list item
- p.listItem = true
- } else {
- // maybe list item continuation
- loc = leadingSpaceRe.FindStringIndex(line[q:])
- }
- if loc != nil {
- t = q + loc[1]
- } else {
- // no list at all
- t = q
- }
-
- // check if there is trailing whitespace, indicating format=flowed
- loc = trailingSpaceRe.FindStringIndex(line[t:])
- if loc != nil {
- p.flowed = true
- // trim whitespace
- line = line[:t+loc[0]]
- }
-
- p.quotes = line[:q]
- p.leader = strings.Repeat(" ", runewidth.StringWidth(line[q:t]))
- p.text = line[q:]
-
- // compute the ratio of letters in the actual text
- onlyLetters := strings.TrimLeft(line[q:], " ")
- totalLen := runewidth.StringWidth(onlyLetters)
- if totalLen == 0 {
- // to avoid division by zero
- totalLen = 1
- }
- onlyLetters = notLetterRe.ReplaceAllLiteralString(onlyLetters, "")
- p.proseRatio = 100 * runewidth.StringWidth(onlyLetters) / totalLen
-
- return p
-}
-
-// Return true if a paragraph is a continuation of the current one.
-func (p *paragraph) isContinuation(
- next *paragraph, reflow bool, proseRatio int,
-) bool {
- switch {
- case next.listItem:
- // new list items always start a new paragraph
- return false
- case next.proseRatio < proseRatio || p.proseRatio < proseRatio:
- // does not look like prose, maybe ascii art
- return false
- case next.quotes != p.quotes || next.leader != p.leader:
- // quote level and/or list item leader have changed
- return false
- case len(strings.Trim(next.text, " ")) == 0:
- // empty line
- return false
- case p.flowed:
- // current paragraph has trailing space, indicating
- // format=flowed
- return true
- case reflow:
- // user forced paragraph reflow on the command line
- return true
- default:
- return false
- }
-}
-
-// Join next paragraph into current one.
-func (p *paragraph) join(next *paragraph) {
- if p.text == "" {
- p.text = next.text
- } else {
- p.text = p.text + " " + strings.Trim(next.text, " ")
- }
- p.proseRatio = (p.proseRatio + next.proseRatio) / 2
- p.flowed = next.flowed
-}
-
-// Write a paragraph, wrapping at words boundaries.
-//
-// Only try to do word wrapping on things that look like prose. When the text
-// contains too many non-letter characters, print it as-is.
-func (p *paragraph) write(out io.Writer, margin int, proseRatio int) {
- leader := ""
- more := true
- quotesWidth := runewidth.StringWidth(p.quotes)
- for more {
- var line string
- width := quotesWidth + runewidth.StringWidth(leader)
- remain := runewidth.StringWidth(p.text)
- if width+remain <= margin || p.proseRatio < proseRatio {
- // whole paragraph fits on a single line
- line = p.text
- p.text = ""
- more = false
- } else {
- // find split point, preferably before margin
- split := -1
- w := 0
- for i, r := range p.text {
- w += runewidth.RuneWidth(r)
- if width+w > margin && split != -1 {
- break
- }
- if r == ' ' {
- split = i
- }
- }
- if split == -1 {
- // no space found to split, print a long line
- line = p.text
- p.text = ""
- more = false
- } else {
- line = p.text[:split]
- // find start of next word
- for split < len(p.text) && p.text[split] == ' ' {
- split++
- }
- if split < len(p.text) {
- p.text = p.text[split:]
- } else {
- // only trailing whitespace, we're done
- p.text = ""
- more = false
- }
- }
- }
- fmt.Fprintf(out, "%s%s%s\n", p.quotes, leader, line)
- leader = p.leader
- }
-}
-
-var (
- patchSubjectRe = regexp.MustCompile(`\bPATCH\b`)
- listItemRe = regexp.MustCompile(`^\s*([\-\*\.]|[a-z\d]{1,2}[\)\]\.])\s+`)
- leadingSpaceRe = regexp.MustCompile(`^\s+`)
- trailingSpaceRe = regexp.MustCompile(`\s+$`)
- notLetterRe = regexp.MustCompile(`[^\pL]`)
-)
generated by cgit (git 2.34.1) at 2024-09-19 16:32:33 +0000