sucrase/dist/TokenProcessor.js

Super-fast alternative to Babel for when you can target modern JS runtimes

"use strict";Object.defineProperty(exports, "__esModule", {value: true});

var _types = require('./parser/tokenizer/types');






 class TokenProcessor {
   __init() {this.resultCode = ""}
   __init2() {this.tokenIndex = 0}

  constructor(
     code,
     tokens,
     isFlowEnabled,
  ) {;this.code = code;this.tokens = tokens;this.isFlowEnabled = isFlowEnabled;TokenProcessor.prototype.__init.call(this);TokenProcessor.prototype.__init2.call(this);}

  /**
   * Make a new TokenProcessor for things like lookahead.
   */
  snapshot() {
    return {resultCode: this.resultCode, tokenIndex: this.tokenIndex};
  }

  restoreToSnapshot(snapshot) {
    this.resultCode = snapshot.resultCode;
    this.tokenIndex = snapshot.tokenIndex;
  }

  getResultCodeIndex() {
    return this.resultCode.length;
  }

  reset() {
    this.resultCode = "";
    this.tokenIndex = 0;
  }

  matchesContextualAtIndex(index, contextualKeyword) {
    return (
      this.matches1AtIndex(index, _types.TokenType.name) &&
      this.tokens[index].contextualKeyword === contextualKeyword
    );
  }

  identifierNameAtIndex(index) {
    // TODO: We need to process escapes since technically you can have unicode escapes in variable
    // names.
    return this.identifierNameForToken(this.tokens[index]);
  }

  identifierName() {
    return this.identifierNameForToken(this.currentToken());
  }

  identifierNameForToken(token) {
    return this.code.slice(token.start, token.end);
  }

  rawCodeForToken(token) {
    return this.code.slice(token.start, token.end);
  }

  stringValueAtIndex(index) {
    return this.stringValueForToken(this.tokens[index]);
  }

  stringValue() {
    return this.stringValueForToken(this.currentToken());
  }

  stringValueForToken(token) {
    // This is used to identify when two imports are the same and to resolve TypeScript enum keys.
    // Ideally we'd process escapes within the strings, but for now we pretty much take the raw
    // code.
    return this.code.slice(token.start + 1, token.end - 1);
  }

  matches1AtIndex(index, t1) {
    return this.tokens[index].type === t1;
  }

  matches2AtIndex(index, t1, t2) {
    return this.tokens[index].type === t1 && this.tokens[index + 1].type === t2;
  }

  matches3AtIndex(index, t1, t2, t3) {
    return (
      this.tokens[index].type === t1 &&
      this.tokens[index + 1].type === t2 &&
      this.tokens[index + 2].type === t3
    );
  }

  matches1(t1) {
    return this.tokens[this.tokenIndex].type === t1;
  }

  matches2(t1, t2) {
    return this.tokens[this.tokenIndex].type === t1 && this.tokens[this.tokenIndex + 1].type === t2;
  }

  matches3(t1, t2, t3) {
    return (
      this.tokens[this.tokenIndex].type === t1 &&
      this.tokens[this.tokenIndex + 1].type === t2 &&
      this.tokens[this.tokenIndex + 2].type === t3
    );
  }

  matches4(t1, t2, t3, t4) {
    return (
      this.tokens[this.tokenIndex].type === t1 &&
      this.tokens[this.tokenIndex + 1].type === t2 &&
      this.tokens[this.tokenIndex + 2].type === t3 &&
      this.tokens[this.tokenIndex + 3].type === t4
    );
  }

  matches5(t1, t2, t3, t4, t5) {
    return (
      this.tokens[this.tokenIndex].type === t1 &&
      this.tokens[this.tokenIndex + 1].type === t2 &&
      this.tokens[this.tokenIndex + 2].type === t3 &&
      this.tokens[this.tokenIndex + 3].type === t4 &&
      this.tokens[this.tokenIndex + 4].type === t5
    );
  }

  matchesContextual(contextualKeyword) {
    return this.matchesContextualAtIndex(this.tokenIndex, contextualKeyword);
  }

  matchesContextIdAndLabel(type, contextId) {
    return this.matches1(type) && this.currentToken().contextId === contextId;
  }

  previousWhitespaceAndComments() {
    let whitespaceAndComments = this.code.slice(
      this.tokenIndex > 0 ? this.tokens[this.tokenIndex - 1].end : 0,
      this.tokenIndex < this.tokens.length ? this.tokens[this.tokenIndex].start : this.code.length,
    );
    if (this.isFlowEnabled) {
      whitespaceAndComments = whitespaceAndComments.replace(/@flow/g, "");
    }
    return whitespaceAndComments;
  }

  replaceToken(newCode) {
    this.resultCode += this.previousWhitespaceAndComments();
    this.resultCode += newCode;
    this.tokenIndex++;
  }

  replaceTokenTrimmingLeftWhitespace(newCode) {
    this.resultCode += this.previousWhitespaceAndComments().replace(/[^\r\n]/g, "");
    this.resultCode += newCode;
    this.tokenIndex++;
  }

  removeInitialToken() {
    this.replaceToken("");
  }

  removeToken() {
    this.replaceTokenTrimmingLeftWhitespace("");
  }

  copyExpectedToken(tokenType) {
    if (this.tokens[this.tokenIndex].type !== tokenType) {
      throw new Error(`Expected token ${tokenType}`);
    }
    this.copyToken();
  }

  copyToken() {
    this.resultCode += this.previousWhitespaceAndComments();
    this.resultCode += this.code.slice(
      this.tokens[this.tokenIndex].start,
      this.tokens[this.tokenIndex].end,
    );
    this.tokenIndex++;
  }

  copyTokenWithPrefix(prefix) {
    this.resultCode += this.previousWhitespaceAndComments();
    this.resultCode += prefix;
    this.resultCode += this.code.slice(
      this.tokens[this.tokenIndex].start,
      this.tokens[this.tokenIndex].end,
    );
    this.tokenIndex++;
  }

  appendCode(code) {
    this.resultCode += code;
  }

  currentToken() {
    return this.tokens[this.tokenIndex];
  }

  currentTokenCode() {
    const token = this.currentToken();
    return this.code.slice(token.start, token.end);
  }

  tokenAtRelativeIndex(relativeIndex) {
    return this.tokens[this.tokenIndex + relativeIndex];
  }

  currentIndex() {
    return this.tokenIndex;
  }

  /**
   * Move to the next token. Only suitable in preprocessing steps. When
   * generating new code, you should use copyToken or removeToken.
   */
  nextToken() {
    if (this.tokenIndex === this.tokens.length) {
      throw new Error("Unexpectedly reached end of input.");
    }
    this.tokenIndex++;
  }

  previousToken() {
    this.tokenIndex--;
  }

  finish() {
    if (this.tokenIndex !== this.tokens.length) {
      throw new Error("Tried to finish processing tokens before reaching the end.");
    }
    this.resultCode += this.previousWhitespaceAndComments();
    return this.resultCode;
  }

  isAtEnd() {
    return this.tokenIndex === this.tokens.length;
  }
} exports.default = TokenProcessor;