MacroExpander.java

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * This file is part of SableCC.                             *
 * See the file "LICENSE" for copyright information and the  *
 * terms and conditions for copying, distribution and        *
 * modification of SableCC.                                  *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package org.sablecc.sablecc;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;

@SuppressWarnings({"rawtypes", "unchecked"})
public class MacroExpander {
    private static final String MACRO = "Macro:";
//  private static final String lineSeparator = System.getProperty("line.separator");

    private Map macros = new TypedTreeMap(
            StringComparator.instance,
            StringCast.instance,
            ListCast.instance);

    public MacroExpander(Reader in) throws IOException {
        BufferedReader br = new BufferedReader(in);
        while (readInMacro(br))
            ;
        in.close();
    }

    private boolean readInMacro(BufferedReader in) throws IOException {
        String line;
        while ((line = in.readLine()) != null) {
            if (line.startsWith(MACRO)) {
                String name = line.substring(MACRO.length());
                List macro = new TypedLinkedList(StringCast.instance);

                while ((line = in.readLine()) != null) {
                    if (line.equals("$")) {
                        macros.put(name, macro);
                        return true;
                    }

                    macro.add(line);
                }

                macros.put(name, macro);
                return false;
            }
        }

        return false;
    }

    @Override
    public String toString() {
        return this.getClass().getName() + macros;
    }

    public void apply(BufferedWriter out, String macroName) throws IOException {
        apply(out, macroName, null);
    }

    public void apply(BufferedWriter out, String macroName, String[] arguments) throws IOException {
        List macro = (List) macros.get(macroName);

        for (ListIterator li = macro.listIterator(); li.hasNext(); ) {
            if (li.nextIndex() != 0) {
                out.newLine();
            }

            String line = (String) li.next();
            char c;

            for (int i = 0; i < line.length(); i++) {
                if ((c = line.charAt(i)) == '$') {
                    StringBuffer index = new StringBuffer();

                    while ((c = line.charAt(++i)) != '$') {
                        index.append(c);
                    }

                    if (index.length() == 0) {
                        out.write('$');
                    } else {
                        out.write(arguments[Integer.parseInt(index.toString())]);
                    }
                } else {
                    out.write(c);
                }
            }
        }
    }
}