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- 'use strict';
-
- var INITIAL_STATE = 1;
- var FAIL_STATE = 0;
- /**
- * A StateMachine represents a deterministic finite automaton.
- * It can perform matches over a sequence of values, similar to a regular expression.
- */
-
- class StateMachine {
- constructor(dfa) {
- this.stateTable = dfa.stateTable;
- this.accepting = dfa.accepting;
- this.tags = dfa.tags;
- }
- /**
- * Returns an iterable object that yields pattern matches over the input sequence.
- * Matches are of the form [startIndex, endIndex, tags].
- */
-
-
- match(str) {
- var self = this;
- return {
- *[Symbol.iterator]() {
- var state = INITIAL_STATE;
- var startRun = null;
- var lastAccepting = null;
- var lastState = null;
-
- for (var p = 0; p < str.length; p++) {
- var c = str[p];
- lastState = state;
- state = self.stateTable[state][c];
-
- if (state === FAIL_STATE) {
- // yield the last match if any
- if (startRun != null && lastAccepting != null && lastAccepting >= startRun) {
- yield [startRun, lastAccepting, self.tags[lastState]];
- } // reset the state as if we started over from the initial state
-
-
- state = self.stateTable[INITIAL_STATE][c];
- startRun = null;
- } // start a run if not in the failure state
-
-
- if (state !== FAIL_STATE && startRun == null) {
- startRun = p;
- } // if accepting, mark the potential match end
-
-
- if (self.accepting[state]) {
- lastAccepting = p;
- } // reset the state to the initial state if we get into the failure state
-
-
- if (state === FAIL_STATE) {
- state = INITIAL_STATE;
- }
- } // yield the last match if any
-
-
- if (startRun != null && lastAccepting != null && lastAccepting >= startRun) {
- yield [startRun, lastAccepting, self.tags[state]];
- }
- }
-
- };
- }
- /**
- * For each match over the input sequence, action functions matching
- * the tag definitions in the input pattern are called with the startIndex,
- * endIndex, and sub-match sequence.
- */
-
-
- apply(str, actions) {
- for (var [start, end, tags] of this.match(str)) {
- for (var tag of tags) {
- if (typeof actions[tag] === 'function') {
- actions[tag](start, end, str.slice(start, end + 1));
- }
- }
- }
- }
-
- }
-
- module.exports = StateMachine;
- //# sourceMappingURL=index.js.map
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