--- /dev/null
+/**
+ * @fileoverview Translates tokens between Acorn format and Esprima format.
+ * @author Nicholas C. Zakas
+ */
+/* eslint no-underscore-dangle: 0 */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+// none!
+
+//------------------------------------------------------------------------------
+// Private
+//------------------------------------------------------------------------------
+
+
+// Esprima Token Types
+const Token = {
+ Boolean: "Boolean",
+ EOF: "<end>",
+ Identifier: "Identifier",
+ Keyword: "Keyword",
+ Null: "Null",
+ Numeric: "Numeric",
+ Punctuator: "Punctuator",
+ String: "String",
+ RegularExpression: "RegularExpression",
+ Template: "Template",
+ JSXIdentifier: "JSXIdentifier",
+ JSXText: "JSXText"
+};
+
+/**
+ * Converts part of a template into an Esprima token.
+ * @param {AcornToken[]} tokens The Acorn tokens representing the template.
+ * @param {string} code The source code.
+ * @returns {EsprimaToken} The Esprima equivalent of the template token.
+ * @private
+ */
+function convertTemplatePart(tokens, code) {
+ const firstToken = tokens[0],
+ lastTemplateToken = tokens[tokens.length - 1];
+
+ const token = {
+ type: Token.Template,
+ value: code.slice(firstToken.start, lastTemplateToken.end)
+ };
+
+ if (firstToken.loc) {
+ token.loc = {
+ start: firstToken.loc.start,
+ end: lastTemplateToken.loc.end
+ };
+ }
+
+ if (firstToken.range) {
+ token.start = firstToken.range[0];
+ token.end = lastTemplateToken.range[1];
+ token.range = [token.start, token.end];
+ }
+
+ return token;
+}
+
+/**
+ * Contains logic to translate Acorn tokens into Esprima tokens.
+ * @param {Object} acornTokTypes The Acorn token types.
+ * @param {string} code The source code Acorn is parsing. This is necessary
+ * to correct the "value" property of some tokens.
+ * @constructor
+ */
+function TokenTranslator(acornTokTypes, code) {
+
+ // token types
+ this._acornTokTypes = acornTokTypes;
+
+ // token buffer for templates
+ this._tokens = [];
+
+ // track the last curly brace
+ this._curlyBrace = null;
+
+ // the source code
+ this._code = code;
+
+}
+
+TokenTranslator.prototype = {
+ constructor: TokenTranslator,
+
+ /**
+ * Translates a single Esprima token to a single Acorn token. This may be
+ * inaccurate due to how templates are handled differently in Esprima and
+ * Acorn, but should be accurate for all other tokens.
+ * @param {AcornToken} token The Acorn token to translate.
+ * @param {Object} extra Espree extra object.
+ * @returns {EsprimaToken} The Esprima version of the token.
+ */
+ translate(token, extra) {
+
+ const type = token.type,
+ tt = this._acornTokTypes;
+
+ if (type === tt.name) {
+ token.type = Token.Identifier;
+
+ // TODO: See if this is an Acorn bug
+ if (token.value === "static") {
+ token.type = Token.Keyword;
+ }
+
+ if (extra.ecmaVersion > 5 && (token.value === "yield" || token.value === "let")) {
+ token.type = Token.Keyword;
+ }
+
+ } else if (type === tt.semi || type === tt.comma ||
+ type === tt.parenL || type === tt.parenR ||
+ type === tt.braceL || type === tt.braceR ||
+ type === tt.dot || type === tt.bracketL ||
+ type === tt.colon || type === tt.question ||
+ type === tt.bracketR || type === tt.ellipsis ||
+ type === tt.arrow || type === tt.jsxTagStart ||
+ type === tt.incDec || type === tt.starstar ||
+ type === tt.jsxTagEnd || type === tt.prefix ||
+ type === tt.questionDot ||
+ (type.binop && !type.keyword) ||
+ type.isAssign) {
+
+ token.type = Token.Punctuator;
+ token.value = this._code.slice(token.start, token.end);
+ } else if (type === tt.jsxName) {
+ token.type = Token.JSXIdentifier;
+ } else if (type.label === "jsxText" || type === tt.jsxAttrValueToken) {
+ token.type = Token.JSXText;
+ } else if (type.keyword) {
+ if (type.keyword === "true" || type.keyword === "false") {
+ token.type = Token.Boolean;
+ } else if (type.keyword === "null") {
+ token.type = Token.Null;
+ } else {
+ token.type = Token.Keyword;
+ }
+ } else if (type === tt.num) {
+ token.type = Token.Numeric;
+ token.value = this._code.slice(token.start, token.end);
+ } else if (type === tt.string) {
+
+ if (extra.jsxAttrValueToken) {
+ extra.jsxAttrValueToken = false;
+ token.type = Token.JSXText;
+ } else {
+ token.type = Token.String;
+ }
+
+ token.value = this._code.slice(token.start, token.end);
+ } else if (type === tt.regexp) {
+ token.type = Token.RegularExpression;
+ const value = token.value;
+
+ token.regex = {
+ flags: value.flags,
+ pattern: value.pattern
+ };
+ token.value = `/${value.pattern}/${value.flags}`;
+ }
+
+ return token;
+ },
+
+ /**
+ * Function to call during Acorn's onToken handler.
+ * @param {AcornToken} token The Acorn token.
+ * @param {Object} extra The Espree extra object.
+ * @returns {void}
+ */
+ onToken(token, extra) {
+
+ const that = this,
+ tt = this._acornTokTypes,
+ tokens = extra.tokens,
+ templateTokens = this._tokens;
+
+ /**
+ * Flushes the buffered template tokens and resets the template
+ * tracking.
+ * @returns {void}
+ * @private
+ */
+ function translateTemplateTokens() {
+ tokens.push(convertTemplatePart(that._tokens, that._code));
+ that._tokens = [];
+ }
+
+ if (token.type === tt.eof) {
+
+ // might be one last curlyBrace
+ if (this._curlyBrace) {
+ tokens.push(this.translate(this._curlyBrace, extra));
+ }
+
+ return;
+ }
+
+ if (token.type === tt.backQuote) {
+
+ // if there's already a curly, it's not part of the template
+ if (this._curlyBrace) {
+ tokens.push(this.translate(this._curlyBrace, extra));
+ this._curlyBrace = null;
+ }
+
+ templateTokens.push(token);
+
+ // it's the end
+ if (templateTokens.length > 1) {
+ translateTemplateTokens();
+ }
+
+ return;
+ }
+ if (token.type === tt.dollarBraceL) {
+ templateTokens.push(token);
+ translateTemplateTokens();
+ return;
+ }
+ if (token.type === tt.braceR) {
+
+ // if there's already a curly, it's not part of the template
+ if (this._curlyBrace) {
+ tokens.push(this.translate(this._curlyBrace, extra));
+ }
+
+ // store new curly for later
+ this._curlyBrace = token;
+ return;
+ }
+ if (token.type === tt.template || token.type === tt.invalidTemplate) {
+ if (this._curlyBrace) {
+ templateTokens.push(this._curlyBrace);
+ this._curlyBrace = null;
+ }
+
+ templateTokens.push(token);
+ return;
+ }
+
+ if (this._curlyBrace) {
+ tokens.push(this.translate(this._curlyBrace, extra));
+ this._curlyBrace = null;
+ }
+
+ tokens.push(this.translate(token, extra));
+ }
+};
+
+//------------------------------------------------------------------------------
+// Public
+//------------------------------------------------------------------------------
+
+module.exports = TokenTranslator;