com.google.template.soy.shared.RangeArgs.java Source code

Introduction

Here is the source code for com.google.template.soy.shared.RangeArgs.java

Source

/*
 * Copyright 2018 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.shared;

import com.google.auto.value.AutoValue;
import com.google.common.base.Optional;
import com.google.template.soy.basicfunctions.RangeFunction;
import com.google.template.soy.exprtree.ExprNode;
import com.google.template.soy.exprtree.FunctionNode;
import com.google.template.soy.soytree.ForNode;
import java.util.List;

/**
 * A class that represents the arguments of a {@code range(...)} expression in a {@code {for ...}}
 * loop statement.
 */
@AutoValue
public abstract class RangeArgs {
    private static RangeArgs create(List<ExprNode> args) {
        switch (args.size()) {
        case 1:
            return new AutoValue_RangeArgs(Optional.<ExprNode>absent(), args.get(0), Optional.<ExprNode>absent());
        case 2:
            return new AutoValue_RangeArgs(Optional.of(args.get(0)), args.get(1), Optional.<ExprNode>absent());
        case 3:
            return new AutoValue_RangeArgs(Optional.of(args.get(0)), args.get(1), Optional.of(args.get(2)));
        default:
            throw new AssertionError();
        }
    }

    /**
     * Returns a optional {@link RangeArgs} object if the for loop expression is a {@code range(...)}
     * expression.
     */
    public static final Optional<RangeArgs> createFromNode(ForNode node) {
        if (node.getExpr().getRoot() instanceof FunctionNode) {
            FunctionNode fn = (FunctionNode) node.getExpr().getRoot();
            if (fn.getSoyFunction() instanceof RangeFunction) {
                return Optional.of(create(fn.getChildren()));
            }
        }
        return Optional.absent();
    }

    /** The expression for the iteration start point. Default is {@code 0}. */
    public abstract Optional<ExprNode> start();

    /** The expression for the iteration end point. This is interpreted as an exclusive limit. */
    public abstract ExprNode limit();

    /** The expression for the iteration increment. Default is {@code 1}. */
    public abstract Optional<ExprNode> increment();
}