liquidjs/src/parser/match-operator.ts

import { IDENTIFIER } from '../util/character'
import { Trie } from '../util/operator-trie'

export function matchOperator (str: string, begin: number, trie: Trie, end = str.length) {
  let node = trie
  let i = begin
  let info
  while (node[str[i]] && i < end) {
    node = node[str[i++]]
    if (node['end']) info = node
  }
  if (!info) return -1
  if (info['needBoundary'] && str.charCodeAt(i) & IDENTIFIER) return -1
  return i
}