go-org-orgwiki/org/list.go
Niklas Fasching b61e49eb85 Preserve whitespace (indentation) inside paragraphs
We want original whitespace to be rendered in some cases (e.g. verse
blocks). This requires information about the original whitespace to be
preserved during paragraph parsing. As html ignores (collapses) whitespace by
default we don't have to adapt the html writer and can just selectively enable
rendering of the preseverved whitespace wherever we want it using
css (white-space: pre).

To differentiate meaningful whitespace from document structure based
indentation (i.e. list item base indentation) we need to introduce
document.baseLvl. A paragraph by itself does not have enough information to
differentiate both kinds of whitespace and needs this information as context
[0].

As we're already touching list indentation i went along and improved (fixed?)
descriptive list item indentation rendering in the org writer (it should match
emacs tab behavior - i.e. indent subsequent lines up to the `:: `).

[0] e.g. list items can contain blank lines - a paragraph starting with a blank
line would not know that it is part of a list item / has a base indentation -
the blank line would suggest a baseLvl of 0.
2019-12-22 14:17:14 +01:00

118 lines
3.4 KiB
Go

package org
import (
"fmt"
"regexp"
"strings"
"unicode"
)
type List struct {
Kind string
Items []Node
}
type ListItem struct {
Bullet string
Status string
Children []Node
}
type DescriptiveListItem struct {
Bullet string
Status string
Term []Node
Details []Node
}
var unorderedListRegexp = regexp.MustCompile(`^(\s*)([+*-])(\s+(.*)|$)`)
var orderedListRegexp = regexp.MustCompile(`^(\s*)(([0-9]+|[a-zA-Z])[.)])(\s+(.*)|$)`)
var descriptiveListItemRegexp = regexp.MustCompile(`\s::(\s|$)`)
var listItemStatusRegexp = regexp.MustCompile(`\[( |X|-)\]\s`)
func lexList(line string) (token, bool) {
if m := unorderedListRegexp.FindStringSubmatch(line); m != nil {
return token{"unorderedList", len(m[1]), m[4], m}, true
} else if m := orderedListRegexp.FindStringSubmatch(line); m != nil {
return token{"orderedList", len(m[1]), m[5], m}, true
}
return nilToken, false
}
func isListToken(t token) bool {
return t.kind == "unorderedList" || t.kind == "orderedList"
}
func listKind(t token) (string, string) {
kind := ""
switch bullet := t.matches[2]; {
case bullet == "*" || bullet == "+" || bullet == "-":
kind = "unordered"
case unicode.IsLetter(rune(bullet[0])), unicode.IsDigit(rune(bullet[0])):
kind = "ordered"
default:
panic(fmt.Sprintf("bad list bullet '%s': %#v", bullet, t))
}
if descriptiveListItemRegexp.MatchString(t.content) {
return kind, "descriptive"
}
return kind, kind
}
func (d *Document) parseList(i int, parentStop stopFn) (int, Node) {
start, lvl := i, d.tokens[i].lvl
listMainKind, kind := listKind(d.tokens[i])
list := List{Kind: kind}
stop := func(*Document, int) bool {
if parentStop(d, i) || d.tokens[i].lvl != lvl || !isListToken(d.tokens[i]) {
return true
}
itemMainKind, _ := listKind(d.tokens[i])
return itemMainKind != listMainKind
}
for !stop(d, i) {
consumed, node := d.parseListItem(list, i, parentStop)
i += consumed
list.Items = append(list.Items, node)
}
return i - start, list
}
func (d *Document) parseListItem(l List, i int, parentStop stopFn) (int, Node) {
start, nodes, bullet := i, []Node{}, d.tokens[i].matches[2]
minIndent, dterm, content, status := d.tokens[i].lvl+len(bullet), "", d.tokens[i].content, ""
originalBaseLvl := d.baseLvl
d.baseLvl = minIndent + 1
if m := listItemStatusRegexp.FindStringSubmatch(content); m != nil {
status, content = m[1], content[len("[ ] "):]
}
if l.Kind == "descriptive" {
if m := descriptiveListItemRegexp.FindStringIndex(content); m != nil {
dterm, content = content[:m[0]], content[m[1]:]
d.baseLvl = strings.Index(d.tokens[i].matches[0], " ::") + 4
}
}
d.tokens[i] = tokenize(strings.Repeat(" ", minIndent) + content)
stop := func(d *Document, i int) bool {
if parentStop(d, i) {
return true
}
t := d.tokens[i]
return t.lvl < minIndent && !(t.kind == "text" && t.content == "")
}
for !stop(d, i) && (i <= start+1 || !isSecondBlankLine(d, i)) {
consumed, node := d.parseOne(i, stop)
i += consumed
nodes = append(nodes, node)
}
d.baseLvl = originalBaseLvl
if l.Kind == "descriptive" {
return i - start, DescriptiveListItem{bullet, status, d.parseInline(dterm), nodes}
}
return i - start, ListItem{bullet, status, nodes}
}
func (n List) String() string { return orgWriter.WriteNodesAsString(n) }
func (n ListItem) String() string { return orgWriter.WriteNodesAsString(n) }
func (n DescriptiveListItem) String() string { return orgWriter.WriteNodesAsString(n) }