decaffeinate-parser/dist/mappers/mapSwitch.js

A better AST for CoffeeScript, inspired by CoffeeScriptRedux.

"use strict";
exports.__esModule = true;
var SourceType_1 = require("coffee-lex/dist/SourceType");
var nodes_1 = require("../nodes");
var getLocation_1 = require("../util/getLocation");
var mapAny_1 = require("./mapAny");
var mapPossiblyEmptyBlock_1 = require("./mapPossiblyEmptyBlock");
function mapSwitch(context, node) {
    var _a = getLocation_1["default"](context, node), line = _a.line, column = _a.column, start = _a.start, end = _a.end, raw = _a.raw;
    var expression = node.subject ? mapAny_1["default"](context, node.subject) : null;
    var cases = node.cases.map(function (_a) {
        var conditions = _a[0], body = _a[1];
        if (!Array.isArray(conditions)) {
            conditions = [conditions];
        }
        var switchConditions = conditions.map(function (condition) {
            return mapAny_1["default"](context, condition);
        });
        var consequent = mapPossiblyEmptyBlock_1["default"](context, body);
        var whenToken = getWhenTokenBeforeOffset(context, switchConditions[0].start, start);
        var locationForIndex = context.linesAndColumns.locationForIndex(whenToken.start);
        if (!locationForIndex) {
            throw new Error("cannot map WHEN token start to line/column: " + whenToken.start);
        }
        var caseLine = locationForIndex.line, caseColumn = locationForIndex.column;
        var end = getLocation_1["default"](context, body).end;
        return new nodes_1.SwitchCase(caseLine + 1, caseColumn + 1, whenToken.start, end, context.source.slice(whenToken.start, end), switchConditions, consequent);
    });
    return new nodes_1.Switch(line, column, start, end, raw, expression, cases, mapPossiblyEmptyBlock_1["default"](context, node.otherwise));
}
exports["default"] = mapSwitch;
function getWhenTokenBeforeOffset(context, offset, lowerBound) {
    var offsetTokenIndex = context.sourceTokens.indexOfTokenNearSourceIndex(offset);
    var lowerBoundTokenIndex = context.sourceTokens.indexOfTokenNearSourceIndex(lowerBound);
    var whenTokenIndex = context.sourceTokens.lastIndexOfTokenMatchingPredicate(function (token) { return token.type === SourceType_1["default"].WHEN; }, offsetTokenIndex, lowerBoundTokenIndex);
    if (whenTokenIndex) {
        var whenToken = context.sourceTokens.tokenAtIndex(whenTokenIndex);
        if (whenToken) {
            return whenToken;
        }
    }
    throw new Error("unable to find WHEN token before " + offset + " (lower bound: " + lowerBound + ")");
}