com.google.api.codegen.util.CommonAcronyms.java Source code

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Here is the source code for com.google.api.codegen.util.CommonAcronyms.java

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/* Copyright 2016 Google LLC
 *
 * 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
 *
 *      https://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.api.codegen.util;

import com.google.common.base.CaseFormat;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Utility class to replace fully capitalized common acronyms with an upper camel interpretation.
 */
public class CommonAcronyms {
    private static final ImmutableSet<String> ACRONYMS = ImmutableSet.<String>builder().add("IAM").add("HTTP")
            // TODO(andrealin): add "HTTPS"
            .add("XML").add("API").add("SQL").build();

    /** Represents the notion of whether a name piece is normal or an upper-case acronym. */
    public enum NamePieceCasingType {
        NORMAL, UPPER_ACRONYM;
    }

    /** Represents a name piece plus its NamePieceCasingType. */
    public static class SubNamePiece {
        private final String namePieceString;
        private final NamePieceCasingType type;

        public SubNamePiece(String namePieceString, NamePieceCasingType type) {
            this.namePieceString = namePieceString;
            this.type = type;
        }

        public String namePieceString() {
            return namePieceString;
        }

        public NamePieceCasingType type() {
            return type;
        }
    }

    public static String camelizeUpperAcronyms(String str) {
        StringBuilder builder = new StringBuilder();
        for (SubNamePiece piece : splitByUpperAcronyms(str)) {
            if (piece.type().equals(NamePieceCasingType.UPPER_ACRONYM)) {
                builder.append(CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, piece.namePieceString()));
            } else {
                builder.append(piece.namePieceString());
            }
        }
        return builder.toString();
    }

    public static List<SubNamePiece> splitByUpperAcronyms(String str) {
        List<NamePiecePosition> positions = getNamePiecePositions(str);
        if (positions.size() == 0) {
            return Collections.singletonList(newNormalPiece(str));
        } else {
            return getSubNamePieces(str, positions);
        }
    }

    private static List<NamePiecePosition> getNamePiecePositions(String str) {
        List<NamePiecePosition> positions = new ArrayList<>();
        for (String acronym : ACRONYMS) {
            int startIndex = 0;
            int foundIndex = -1;
            while ((foundIndex = str.indexOf(acronym, startIndex)) != -1) {
                int endIndex = foundIndex + acronym.length();
                positions.add(new NamePiecePosition(foundIndex, endIndex));
                startIndex = endIndex;
            }
        }
        Collections.sort(positions);

        return positions;
    }

    private static List<SubNamePiece> getSubNamePieces(String str, List<NamePiecePosition> positions) {
        Preconditions.checkArgument(positions.size() > 0);

        List<SubNamePiece> result = new ArrayList<>();
        NamePiecePosition lastPos = null;
        for (NamePiecePosition namePiecePos : positions) {
            if (lastPos != null) {
                if (lastPos.overlapsWith(namePiecePos)) {
                    throw new IllegalArgumentException(
                            "CommonAcronyms: A situation where combined acronyms was found. Acronym splitting "
                                    + "is ambiguous. ex. \"APIAMName\".");
                }
            }

            // Add any component of the string that is not part of a previous acronym
            int lastEndIndex = 0;
            if (lastPos != null) {
                lastEndIndex = lastPos.endIndex;
            }
            if (namePiecePos.startIndex > lastEndIndex) {
                String namePiece = str.substring(lastEndIndex, namePiecePos.startIndex);
                result.add(newNormalPiece(namePiece));
            }

            // add the current acronym
            String namePiece = str.substring(namePiecePos.startIndex, namePiecePos.endIndex);
            result.add(new SubNamePiece(namePiece, NamePieceCasingType.UPPER_ACRONYM));

            lastPos = namePiecePos;
        }

        // Add any training component of the string that is not part of a previous acronym
        if (lastPos.endIndex < str.length()) {
            String namePiece = str.substring(lastPos.endIndex, str.length());
            result.add(newNormalPiece(namePiece));
        }

        return result;
    }

    private static SubNamePiece newNormalPiece(String namePiece) {
        return new SubNamePiece(namePiece, NamePieceCasingType.NORMAL);
    }

    private static class NamePiecePosition implements Comparable<NamePiecePosition> {
        public final int startIndex;
        // one past the end of the string
        public final int endIndex;

        public NamePiecePosition(int startIndex, int endIndex) {
            this.startIndex = startIndex;
            this.endIndex = endIndex;
            if (startIndex == endIndex) {
                throw new IllegalArgumentException("Invalid name piece position - zero length: startIndex = "
                        + startIndex + ", endIndex = " + endIndex);
            }
        }

        @Override
        public int compareTo(NamePiecePosition otherPos) {
            int startComp = Integer.compare(startIndex, otherPos.startIndex);
            if (startComp != 0) {
                return startComp;
            }
            return Integer.compare(endIndex, otherPos.endIndex);
        }

        public boolean overlapsWith(NamePiecePosition otherPos) {
            if (otherPos.startIndex < endIndex && otherPos.endIndex > startIndex) {
                return true;
            } else {
                return false;
            }
        }
    }
}