com.google.template.soy.exprparse.ParseErrors.java Source code

Introduction

Here is the source code for com.google.template.soy.exprparse.ParseErrors.java

Source

/*
 * Copyright 2015 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.template.soy.exprparse;

import static com.google.template.soy.base.internal.BaseUtils.formatParseExceptionDetails;

import com.google.common.collect.ImmutableSet;
import com.google.template.soy.base.SourceLocation;
import com.google.template.soy.error.ErrorReporter;
import com.google.template.soy.error.SoyErrorKind;

/**
 * Helpers for interpreting parse errors as soy errors.
 */
final class ParseErrors {

    private static final SoyErrorKind LEGACY_AND_ERROR = SoyErrorKind
            .of("Found use of ''&&'' instead of the ''and'' operator");
    private static final SoyErrorKind LEGACY_OR_ERROR = SoyErrorKind
            .of("Found use of ''||'' instead of the ''or'' operator");
    private static final SoyErrorKind LEGACY_NOT_ERROR = SoyErrorKind
            .of("Found use of ''!'' instead of the ''not'' operator");
    private static final SoyErrorKind LEGACY_DOUBLE_QUOTED_STRING = SoyErrorKind
            .of("Found use of double quotes, Soy strings use single quotes");

    private ParseErrors() {
    }

    static void reportExprParseException(ErrorReporter reporter, SourceLocation location, ParseException e) {
        reportExprParseException(reporter, "", location, e);
    }

    static void reportExprParseException(ErrorReporter reporter, String expectation, SourceLocation location,
            ParseException e) {
        // currentToken is the 'last successfully consumed token', but the error is usually due to the
        // first unsuccessful token.  use that for the source location
        Token errorToken = e.currentToken;
        if (errorToken.next != null) {
            errorToken = errorToken.next;
        }

        // handle a few special cases that come up in v1->v2 migrations.  We have no production rules
        // that reference these tokens so they will always be unexpected.  Another option we could take
        // is add production rules/matchers for these in the expected places (e.q. allow '&&' in the
        // same place we match 'and'), then we could report errors and keep going in the parser.
        switch (errorToken.kind) {
        case ExpressionParserConstants.LEGACY_AND:
            reporter.report(location, LEGACY_AND_ERROR);
            return;
        case ExpressionParserConstants.LEGACY_OR:
            reporter.report(location, LEGACY_OR_ERROR);
            return;
        case ExpressionParserConstants.LEGACY_NOT:
            reporter.report(location, LEGACY_NOT_ERROR);
            return;
        case ExpressionParserConstants.DOUBLE_QUOTE:
            reporter.report(location, LEGACY_DOUBLE_QUOTED_STRING);
            return;
        }
        // otherwise log a generic unexpected token error message
        ImmutableSet.Builder<String> expectedTokenImages = ImmutableSet.builder();
        for (int[] expected : e.expectedTokenSequences) {
            // We only display the first token
            expectedTokenImages.add(getSoyFileParserTokenDisplayName(expected[0]));
        }
        reporter.report(
                // TODO(lukes): we should offset the location by the location of the errorToken however
                // expr source locations are already iffy, so doing random math on them is unlikely to help
                // anything.  Revisit when we stop extracting expressions from SoyNode command texts with
                // regular expressions.
                location, SoyErrorKind.of(expectation + "{0}"),
                formatParseExceptionDetails(errorToken.image, expectedTokenImages.build().asList()));
    }

    /**
     * Returns a human friendly display name for tokens.  By default we use the generated token
     * image which is appropriate for literal tokens.
     */
    private static String getSoyFileParserTokenDisplayName(int tokenId) {
        switch (tokenId) {
        case ExpressionParserConstants.EOF:
            return "eof";
        case ExpressionParserConstants.PRECEDENCE_2_OP:
        case ExpressionParserConstants.PRECEDENCE_3_OP:
        case ExpressionParserConstants.PRECEDENCE_4_OP:
        case ExpressionParserConstants.PRECEDENCE_5_OP:
        case ExpressionParserConstants.PRECEDENCE_6_OP:
        case ExpressionParserConstants.PRECEDENCE_7_OP:
            return "an operator";
        case ExpressionParserConstants.IDENT:
            return "an identifier";
        case ExpressionParserConstants.DOT_IDENT:
        case ExpressionParserConstants.QUESTION_DOT_IDENT:
            return "field access";
        case ExpressionParserConstants.DOLLAR_IDENT:
            return "variable";
        case ExpressionParserConstants.UNEXPECTED_TOKEN:
            throw new AssertionError("we should never expect the unexpected token");
        default:
            return ExpressionParserConstants.tokenImage[tokenId];
        }
    }
}