PrimitiveEnumerableGenerator.java

package org.enumerable.lambda.enumerable.primitives;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.StringWriter;

public class PrimitiveEnumerableGenerator {
    private static final String DIR = "src/main/java/lambda/enumerable/primitives/";
    private static final String SOURCE = "EnumerableDoubles.java";

    public static void main(String[] args) throws Exception {
        String source = readSourceForDouble();

        generateSource(source, "int", "Ints", "Integer", "I");
        generateSource(source, "long", "Longs", "Long", "L");
    }

    static String readSourceForDouble() throws FileNotFoundException, IOException {
        Reader in = new BufferedReader(new FileReader(DIR + SOURCE));
        try {
            StringWriter out = new StringWriter();

            int c = -1;
            while ((c = in.read()) != -1)
                out.write(c);

            return out.toString();
        } finally {
            in.close();
        }
    }

    static void generateSource(String s, String primitiveType, String name, String boxedType, String letterForType)
            throws Exception {
        s = s.replaceAll("double", primitiveType);
        s = s.replaceAll("Doubles", name);
        s = s.replaceAll("Double", boxedType);
        s = s.replaceAll("/\\* don't change \\*/" + primitiveType, "/\\* don't change \\*/double");
        s = s.replaceAll("/\\* don't change \\*/" + boxedType, "/\\* don't change \\*/Double");

        s = s.replaceAll("Fn1D", "Fn1" + letterForType);
        s = s.replaceAll("Fn2DDtoO", "Fn2" + letterForType + letterForType + "toO");
        s = s.replaceAll("Fn2DDtoD", "Fn2" + letterForType + letterForType + "to" + letterForType);

        s = s
                .replace(" */\npublic class", " * <i>This file was generated by\n * "
                        + PrimitiveEnumerableGenerator.class.getName() + " from\n * " + SOURCE
                        + ".</i>\n */\npublic class");

        s = s.replaceAll(" *//.*\n", "");
        s = s.replaceAll("(\\w*?\n){2,}", "\n\n");

        FileWriter writer = new FileWriter(DIR + "Enumerable" + name + ".java");
        try {
            writer.write(s.toString());
        } finally {
            writer.close();
        }

        System.out.println(s);
    }
}