/* -*- Mode: java; tab-width: 4; indent-tabs-mode: 1; c-basic-offset: 4 -*- * * The contents of this file are subject to the Netscape Public * License Version 1.1 (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.mozilla.org/NPL/ * * Software distributed under the License is distributed on an "AS * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or * implied. See the License for the specific language governing * rights and limitations under the License. * * The Original Code is Rhino code, released * May 6, 1999. * * The Initial Developer of the Original Code is Netscape * Communications Corporation.  Portions created by Netscape are * Copyright (C) 1997-1999 Netscape Communications Corporation. All * Rights Reserved. * * Contributor(s): * Igor Bukanov * * Alternatively, the contents of this file may be used under the * terms of the GNU Public License (the "GPL"), in which case the * provisions of the GPL are applicable instead of those above. * If you wish to allow use of your version of this file only * under the terms of the GPL and not to allow others to use your * version of this file under the NPL, indicate your decision by * deleting the provisions above and replace them with the notice * and other provisions required by the GPL.  If you do not delete * the provisions above, a recipient may use your version of this * file under either the NPL or the GPL. */package org.mozilla.javascript.tools.idswitch;import org.mozilla.javascript.EvaluatorException;import org.mozilla.javascript.tools.ToolErrorReporter;public class SwitchGenerator {    String v_switch_label = "L0";    String v_label = "L";    String v_s = "s";    String v_c = "c";    String v_guess = "X";    String v_id = "id";    String v_length_suffix = "_length";    int use_if_threshold = 3;    int char_tail_test_threshold = 2;    private IdValuePair[] pairs;    private String default_value;    private int[] columns;    private boolean c_was_defined;    private CodePrinter P;    private ToolErrorReporter R;    private String source_file;    public CodePrinter getCodePrinter() { return P; }    public void setCodePrinter(CodePrinter value) { P = value; }    public ToolErrorReporter getReporter() { return R; }    public void setReporter(ToolErrorReporter value) { R = value; }    public String getSourceFileName() { return source_file; }    public void setSourceFileName(String value) { source_file = value; }    public void generateSwitch(String[] pairs, String default_value) {        int N = pairs.length / 2;        IdValuePair[] id_pairs = new IdValuePair[N];        for (int i = 0; i != N; ++i) {            id_pairs[i] = new IdValuePair(pairs[2 * i], pairs[2 * i + 1]);        }        generateSwitch(id_pairs, default_value);    }    public void generateSwitch(IdValuePair[] pairs, String default_value) {        int begin = 0;        int end = pairs.length;        if (begin == end) { return; }        this.pairs = pairs;        this.default_value = default_value;        generate_body(begin, end, 2);    }    private void generate_body(int begin, int end, int indent_level) {        P.indent(indent_level);        P.p(v_switch_label); P.p(": { ");        P.p(v_id); P.p(" = "); P.p(default_value);        P.p("; String "); P.p(v_guess); P.p(" = null;");        c_was_defined = false;        int c_def_begin = P.getOffset();        P.p(" int "); P.p(v_c); P.p(';');        int c_def_end = P.getOffset();        P.nl();        generate_length_switch(begin, end, indent_level + 1);        if (!c_was_defined) {            P.erase(c_def_begin, c_def_end);        }        P.indent(indent_level + 1);        P.p("if ("); P.p(v_guess); P.p("!=null && ");        P.p(v_guess); P.p("!="); P.p(v_s);        P.p(" && !"); P.p(v_guess); P.p(".equals("); P.p(v_s); P.p(")) ");        P.p(v_id); P.p(" = "); P.p(default_value); P.p(";"); P.nl();        P.line(indent_level, "}");    }    private void generate_length_switch(int begin, int end, int indent_level) {        sort_pairs(begin, end, -1);        check_all_is_different(begin, end);        int lengths_count = count_different_lengths(begin, end);        columns = new int[pairs[end  - 1].idLength];        boolean use_if;        if (lengths_count <= use_if_threshold) {            use_if = true;            if (lengths_count != 1) {                P.indent(indent_level);                P.p("int "); P.p(v_s); P.p(v_length_suffix);                P.p(" = "); P.p(v_s); P.p(".length();");                P.nl();            }        }        else {            use_if = false;            P.indent(indent_level);            P.p(v_label); P.p(": switch (");            P.p(v_s); P.p(".length()) {");            P.nl();        }        int same_length_begin = begin;        int cur_l = pairs[begin].idLength, l = 0;        for (int i = begin;;) {            ++i;            if (i == end || (l = pairs[i].idLength) != cur_l) {                int next_indent;                if (use_if) {                    P.indent(indent_level);                    if (same_length_begin != begin) { P.p("else "); }                    P.p("if (");                    if (lengths_count == 1) {                        P.p(v_s); P.p(".length()==");                    }                    else {                        P.p(v_s); P.p(v_length_suffix); P.p("==");                    }                    P.p(cur_l);                    P.p(") {");                    next_indent = indent_level + 1;                }                else {                    P.indent(indent_level);                    P.p("case "); P.p(cur_l); P.p(":");                    next_indent = indent_level + 1;                }                generate_letter_switch                    (same_length_begin, i, next_indent, !use_if, use_if);                if (use_if) {                    P.p("}"); P.nl();                }                else {                    P.p("break "); P.p(v_label); P.p(";"); P.nl();                }                if (i == end) { break; }                same_length_begin = i;                cur_l = l;            }        }        if (!use_if) {            P.indent(indent_level); P.p("}"); P.nl();        }    }    private void generate_letter_switch        (int begin, int end,         int indent_level, boolean label_was_defined, boolean inside_if)    {        int L = pairs[begin].idLength;        for (int i = 0; i != L; ++i) {            columns[i] = i;        }        generate_letter_switch_r            (begin, end, L, indent_level, label_was_defined, inside_if);    }    private boolean generate_letter_switch_r        (int begin, int end, int L,         int indent_level, boolean label_was_defined, boolean inside_if)    {        boolean next_is_unreachable = false;        if (begin + 1 == end) {            P.p(' ');            IdValuePair pair = pairs[begin];            if (L > char_tail_test_threshold) {                P.p(v_guess); P.p("="); P.qstring(pair.id); P.p(";");                P.p(v_id); P.p("="); P.p(pair.value); P.p(";");            }            else {                if (L == 0) {                    next_is_unreachable = true;                    P.p(v_id); P.p("="); P.p(pair.value);                    P.p("; break "); P.p(v_switch_label); P.p(";");                }                else {                    P.p("if (");                    int column = columns[0];                    P.p(v_s); P.p(".charAt("); P.p(column); P.p(")==");                    P.qchar(pair.id.charAt(column));                    for (int i = 1; i != L; ++i) {                        P.p(" && ");                        column = columns[i];                        P.p(v_s); P.p(".charAt("); P.p(column); P.p(")==");                        P.qchar(pair.id.charAt(column));                    }                    P.p(") {");                    P.p(v_id); P.p("="); P.p(pair.value);                    P.p("; break "); P.p(v_switch_label); P.p(";}");                }            }            P.p(' ');            return next_is_unreachable;        }