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// For each opening emphasis-like marker find a matching closing one
//
function processDelimiters (delimiters) {
const openersBottom = {}
const max = delimiters.length
if (!max) return
// headerIdx is the first delimiter of the current (where closer is) delimiter run
let headerIdx = 0
let lastTokenIdx = -2 // needs any value lower than -1
const jumps = []
for (let closerIdx = 0; closerIdx < max; closerIdx++) {
const closer = delimiters[closerIdx]
jumps.push(0)
// markers belong to same delimiter run if:
// - they have adjacent tokens
// - AND markers are the same
//
if (delimiters[headerIdx].marker !== closer.marker || lastTokenIdx !== closer.token - 1) {
headerIdx = closerIdx
}
lastTokenIdx = closer.token
// Length is only used for emphasis-specific "rule of 3",
// if it's not defined (in strikethrough or 3rd party plugins),
// we can default it to 0 to disable those checks.
//
closer.length = closer.length || 0
if (!closer.close) continue
// Previously calculated lower bounds (previous fails)
// for each marker, each delimiter length modulo 3,
// and for whether this closer can be an opener;
// https://github.com/commonmark/cmark/commit/34250e12ccebdc6372b8b49c44fab57c72443460
/* eslint-disable-next-line no-prototype-builtins */
if (!openersBottom.hasOwnProperty(closer.marker)) {
openersBottom[closer.marker] = [-1, -1, -1, -1, -1, -1]
}
const minOpenerIdx = openersBottom[closer.marker][(closer.open ? 3 : 0) + (closer.length % 3)]
let openerIdx = headerIdx - jumps[headerIdx] - 1
let newMinOpenerIdx = openerIdx
for (; openerIdx > minOpenerIdx; openerIdx -= jumps[openerIdx] + 1) {
const opener = delimiters[openerIdx]
if (opener.marker !== closer.marker) continue
if (opener.open && opener.end < 0) {
let isOddMatch = false
// from spec:
//
// If one of the delimiters can both open and close emphasis, then the
// sum of the lengths of the delimiter runs containing the opening and
// closing delimiters must not be a multiple of 3 unless both lengths
// are multiples of 3.
//
if (opener.close || closer.open) {
if ((opener.length + closer.length) % 3 === 0) {
if (opener.length % 3 !== 0 || closer.length % 3 !== 0) {
isOddMatch = true
}
}
}
if (!isOddMatch) {
// If previous delimiter cannot be an opener, we can safely skip
// the entire sequence in future checks. This is required to make
// sure algorithm has linear complexity (see *_*_*_*_*_... case).
//
const lastJump = openerIdx > 0 && !delimiters[openerIdx - 1].open
? jumps[openerIdx - 1] + 1
: 0
jumps[closerIdx] = closerIdx - openerIdx + lastJump
jumps[openerIdx] = lastJump
closer.open = false
opener.end = closerIdx
opener.close = false
newMinOpenerIdx = -1
// treat next token as start of run,
// it optimizes skips in **<...>**a**<...>** pathological case
lastTokenIdx = -2
break
}
}
}
if (newMinOpenerIdx !== -1) {
// If match for this delimiter run failed, we want to set lower bound for
// future lookups. This is required to make sure algorithm has linear
// complexity.
//
// See details here:
// https://github.com/commonmark/cmark/issues/178#issuecomment-270417442
//
openersBottom[closer.marker][(closer.open ? 3 : 0) + ((closer.length || 0) % 3)] = newMinOpenerIdx
}
}
}
export default function link_pairs (state) {
const tokens_meta = state.tokens_meta
const max = state.tokens_meta.length
processDelimiters(state.delimiters)
for (let curr = 0; curr < max; curr++) {
if (tokens_meta[curr] && tokens_meta[curr].delimiters) {
processDelimiters(tokens_meta[curr].delimiters)
}
}
}