001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2019 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.api;
021
022import java.util.ArrayList;
023import java.util.List;
024
025/**
026 * Represents a full identifier, including dots, with associated
027 * position information.
028 *
029 * <p>
030 * Identifiers such as {@code java.util.HashMap} are spread across
031 * multiple AST nodes in the syntax tree (three IDENT nodes, two DOT nodes).
032 * A FullIdent represents the whole String (excluding any intermediate
033 * whitespace), which is often easier to work with in Checks.
034 * </p>
035 *
036 * @see TokenTypes#DOT
037 * @see TokenTypes#IDENT
038 **/
039public final class FullIdent {
040
041    /** The list holding subsequent elements of identifier. **/
042    private final List<String> elements = new ArrayList<>();
043    /** The topmost and leftmost AST of the full identifier. */
044    private DetailAST detailAst;
045
046    /** Hide default constructor. */
047    private FullIdent() {
048    }
049
050    /**
051     * Creates a new FullIdent starting from the specified node.
052     * @param ast the node to start from
053     * @return a {@code FullIdent} value
054     */
055    public static FullIdent createFullIdent(DetailAST ast) {
056        final FullIdent ident = new FullIdent();
057        extractFullIdent(ident, ast);
058        return ident;
059    }
060
061    /**
062     * Creates a new FullIdent starting from the child of the specified node.
063     * @param ast the parent node from where to start from
064     * @return a {@code FullIdent} value
065     */
066    public static FullIdent createFullIdentBelow(DetailAST ast) {
067        return createFullIdent(ast.getFirstChild());
068    }
069
070    /**
071     * Gets the text.
072     * @return the text
073     */
074    public String getText() {
075        return String.join("", elements);
076    }
077
078    /**
079     * Gets the topmost leftmost DetailAST for this FullIdent.
080     * @return the topmost leftmost ast
081     */
082    public DetailAST getDetailAst() {
083        return detailAst;
084    }
085
086    /**
087     * Gets the line number.
088     * @return the line number
089     */
090    public int getLineNo() {
091        return detailAst.getLineNo();
092    }
093
094    /**
095     * Gets the column number.
096     * @return the column number
097     */
098    public int getColumnNo() {
099        return detailAst.getColumnNo();
100    }
101
102    @Override
103    public String toString() {
104        return String.join("", elements)
105            + "[" + detailAst.getLineNo() + "x" + detailAst.getColumnNo() + "]";
106    }
107
108    /**
109     * Recursively extract a FullIdent.
110     *
111     * @param full the FullIdent to add to
112     * @param ast the node to recurse from
113     */
114    private static void extractFullIdent(FullIdent full, DetailAST ast) {
115        if (ast != null) {
116            if (ast.getType() == TokenTypes.DOT) {
117                extractFullIdent(full, ast.getFirstChild());
118                full.append(".");
119                extractFullIdent(
120                    full, ast.getFirstChild().getNextSibling());
121            }
122            else if (ast.getType() == TokenTypes.ARRAY_DECLARATOR) {
123                extractFullIdent(full, ast.getFirstChild());
124                full.append("[]");
125            }
126            else {
127                full.append(ast);
128            }
129        }
130    }
131
132    /**
133     * Append the specified text.
134     * @param text the text to append
135     */
136    private void append(String text) {
137        elements.add(text);
138    }
139
140    /**
141     * Append the specified token and also recalibrate the first line and
142     * column.
143     * @param ast the token to append
144     */
145    private void append(DetailAST ast) {
146        elements.add(ast.getText());
147        if (detailAst == null) {
148            detailAst = ast;
149        }
150    }
151
152}