falcor-path-syntax/src/parse-tree/quote.js

Parser for Falcor Path Syntax

var TokenTypes = require('./../TokenTypes');
var E = require('./../exceptions');
var quoteE = E.quote;

/**
 * quote is all the parse tree in between quotes.  This includes the only
 * escaping logic.
 *
 * parse-tree:
 * <opening-quote>(.|(<escape><opening-quote>))*<opening-quote>
 */
module.exports = function quote(tokenizer, openingToken, state, out) {
    var token = tokenizer.next();
    var innerToken = '';
    var openingQuote = openingToken.token;
    var escaping = false;
    var done = false;

    while (!token.done) {

        switch (token.type) {
            case TokenTypes.token:
            case TokenTypes.space:

            case TokenTypes.dotSeparator:
            case TokenTypes.commaSeparator:

            case TokenTypes.openingBracket:
            case TokenTypes.closingBracket:
            case TokenTypes.openingBrace:
            case TokenTypes.closingBrace:
                if (escaping) {
                    E.throwError(quoteE.illegalEscape, tokenizer);
                }

                innerToken += token.token;
                break;


            case TokenTypes.quote:
                // the simple case.  We are escaping
                if (escaping) {
                    innerToken += token.token;
                    escaping = false;
                }

                // its not a quote that is the opening quote
                else if (token.token !== openingQuote) {
                    innerToken += token.token;
                }

                // last thing left.  Its a quote that is the opening quote
                // therefore we must produce the inner token of the indexer.
                else {
                    done = true;
                }

                break;
            case TokenTypes.escape:
                escaping = true;
                break;

            default:
                E.throwError(E.unexpectedToken, tokenizer);
        }

        // If done, leave loop
        if (done) {
            break;
        }

        // Keep cycling through the tokenizer.
        token = tokenizer.next();
    }

    if (innerToken.length === 0) {
        E.throwError(quoteE.empty, tokenizer);
    }

    state.indexer[state.indexer.length] = innerToken;
};