mirror of
https://github.com/42wim/matterbridge.git
synced 2024-12-04 16:32:02 -08:00
148 lines
3.3 KiB
Go
148 lines
3.3 KiB
Go
// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
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// See LICENSE.txt for license information.
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// This package implements a parser for the subset of the CommonMark spec necessary for us to do
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// server-side processing. It is not a full implementation and lacks many features. But it is
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// complete enough to efficiently and accurately allow us to do what we need to like rewrite image
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// URLs for proxying.
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package markdown
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import (
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"strings"
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)
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func isEscapable(c rune) bool {
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return c > ' ' && (c < '0' || (c > '9' && (c < 'A' || (c > 'Z' && (c < 'a' || (c > 'z' && c <= '~'))))))
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}
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func isEscapableByte(c byte) bool {
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return isEscapable(rune(c))
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}
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func isWhitespace(c rune) bool {
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switch c {
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case ' ', '\t', '\n', '\u000b', '\u000c', '\r':
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return true
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}
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return false
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}
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func isWhitespaceByte(c byte) bool {
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return isWhitespace(rune(c))
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}
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func isNumeric(c rune) bool {
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return c >= '0' && c <= '9'
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}
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func isNumericByte(c byte) bool {
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return isNumeric(rune(c))
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}
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func isHex(c rune) bool {
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return isNumeric(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')
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}
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func isHexByte(c byte) bool {
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return isHex(rune(c))
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}
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func isAlphanumeric(c rune) bool {
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return isNumeric(c) || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
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}
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func isAlphanumericByte(c byte) bool {
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return isAlphanumeric(rune(c))
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}
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func nextNonWhitespace(markdown string, position int) int {
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for offset, c := range []byte(markdown[position:]) {
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if !isWhitespaceByte(c) {
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return position + offset
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}
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}
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return len(markdown)
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}
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func nextLine(markdown string, position int) (linePosition int, skippedNonWhitespace bool) {
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for i := position; i < len(markdown); i++ {
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c := markdown[i]
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if c == '\r' {
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if i+1 < len(markdown) && markdown[i+1] == '\n' {
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return i + 2, skippedNonWhitespace
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}
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return i + 1, skippedNonWhitespace
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} else if c == '\n' {
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return i + 1, skippedNonWhitespace
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} else if !isWhitespaceByte(c) {
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skippedNonWhitespace = true
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}
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}
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return len(markdown), skippedNonWhitespace
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}
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func countIndentation(markdown string, r Range) (spaces, bytes int) {
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for i := r.Position; i < r.End; i++ {
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if markdown[i] == ' ' {
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spaces++
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bytes++
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} else if markdown[i] == '\t' {
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spaces += 4
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bytes++
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} else {
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break
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}
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}
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return
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}
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func trimLeftSpace(markdown string, r Range) Range {
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s := markdown[r.Position:r.End]
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trimmed := strings.TrimLeftFunc(s, isWhitespace)
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return Range{r.Position, r.End - (len(s) - len(trimmed))}
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}
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func trimRightSpace(markdown string, r Range) Range {
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s := markdown[r.Position:r.End]
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trimmed := strings.TrimRightFunc(s, isWhitespace)
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return Range{r.Position, r.End - (len(s) - len(trimmed))}
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}
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func relativeToAbsolutePosition(ranges []Range, position int) int {
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rem := position
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for _, r := range ranges {
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l := r.End - r.Position
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if rem < l {
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return r.Position + rem
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}
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rem -= l
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}
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if len(ranges) == 0 {
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return 0
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}
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return ranges[len(ranges)-1].End
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}
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func trimBytesFromRanges(ranges []Range, bytes int) (result []Range) {
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rem := bytes
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for _, r := range ranges {
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if rem == 0 {
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result = append(result, r)
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continue
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}
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l := r.End - r.Position
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if rem < l {
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result = append(result, Range{r.Position + rem, r.End})
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rem = 0
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continue
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}
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rem -= l
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}
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return
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}
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func Parse(markdown string) (*Document, []*ReferenceDefinition) {
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lines := ParseLines(markdown)
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return ParseBlocks(markdown, lines)
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}
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