org.javacc.utils.OutputFileGenerator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of javacc Show documentation
Show all versions of javacc Show documentation
JavaCC is a parser/scanner generator for Java.
/* Copyright (c) 2008, Paul Cager.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.javacc.utils;
import java.io.*;
import java.util.HashMap;
import java.util.Map;
import org.javacc.parser.Options;
/**
* Generates boiler-plate files from templates. Only very basic
* template processing is supplied - if we need something more
* sophisticated I suggest we use a third-party library.
*
* @author paulcager
* @since 4.2
*/
public class OutputFileGenerator {
/**
* @param templateName the name of the template. E.g.
* "/templates/Token.template".
* @param options the processing options in force, such
* as "STATIC=yes"
*/
public OutputFileGenerator(String templateName, Map options) {
this.templateName = templateName;
this.options = options;
}
private final String templateName;
private final Map options;
private String currentLine;
/**
* Generate the output file.
* @param out
* @throws IOException
*/
public void generate(PrintWriter out) throws IOException
{
InputStream is = getClass().getResourceAsStream(templateName);
if (is == null)
throw new IOException("Invalid template name: " + templateName);
BufferedReader in = new BufferedReader(new InputStreamReader(is));
process(in, out, false);
}
private String peekLine(BufferedReader in) throws IOException
{
if (currentLine == null)
currentLine = in.readLine();
return currentLine;
}
private String getLine(BufferedReader in) throws IOException
{
String line = currentLine;
currentLine = null;
if (line == null)
in.readLine();
return line;
}
private boolean evaluate(String condition)
{
condition = condition.trim();
try
{
return new ConditionParser(new StringReader(condition)).CompilationUnit(options);
}
catch (ParseException e)
{
return false;
}
}
private String substitute(String text) throws IOException
{
int startPos;
if ( (startPos = text.indexOf("${")) == -1)
{
return text;
}
// Find matching "}".
int braceDepth = 1;
int endPos = startPos + 2;
while ( endPos < text.length() && braceDepth > 0)
{
if (text.charAt(endPos) == '{')
braceDepth++;
else if (text.charAt(endPos) == '}')
braceDepth--;
endPos++;
}
if (braceDepth != 0)
throw new IOException("Mismatched \"{}\" in template string: " + text);
final String variableExpression = text.substring(startPos + 2, endPos - 1);
// Find the end of the variable name
String value = null;
for (int i = 0; i < variableExpression.length(); i++)
{
char ch = variableExpression.charAt(i);
if (ch == ':' && i < variableExpression.length() - 1 && variableExpression.charAt(i+1) == '-' )
{
value = substituteWithDefault(variableExpression.substring(0, i), variableExpression.substring(i + 2));
break;
}
else if (ch == '?')
{
value = substituteWithConditional(variableExpression.substring(0, i), variableExpression.substring(i + 1));
break;
}
else if (ch != '_' && !Character.isJavaIdentifierPart(ch))
{
throw new IOException("Invalid variable in " + text);
}
}
if (value == null)
{
value = substituteWithDefault(variableExpression, "");
}
return text.substring(0, startPos) + value + text.substring(endPos);
}
/**
* @param substring
* @param defaultValue
* @return
* @throws IOException
*/
private String substituteWithConditional(String variableName, String values) throws IOException
{
// Split values into true and false values.
int pos = values.indexOf(':');
if (pos == -1)
throw new IOException("No ':' separator in " + values);
if (evaluate(variableName))
return substitute(values.substring(0, pos));
else
return substitute(values.substring(pos + 1));
}
/**
* @param variableName
* @param defaultValue
* @return
*/
private String substituteWithDefault(String variableName, String defaultValue) throws IOException
{
Object obj = options.get(variableName.trim());
if (obj == null || obj.toString().length() == 0)
return substitute(defaultValue);
return obj.toString();
}
private void write(PrintWriter out, String text) throws IOException
{
while ( text.indexOf("${") != -1)
{
text = substitute(text);
}
if (Options.isOutputLanguageJava() && Options.getGenerateStringBuilder()) {
text = text.replace("StringBuffer", "StringBuilder");
}
// TODO :: Added by Sreenivas on 12 June 2013 for 6.0 release, merged in to 6.1 release for sake of compatibility by cainsley ... This needs to be removed urgently!!!
if (text.startsWith("\\#")) { // Hack to escape # for C++
text = text.substring(1);
}
out.println(text);
}
private void process(BufferedReader in, PrintWriter out, boolean ignoring)
throws IOException {
// out.println("*** process ignore=" + ignoring + " : " + peekLine(in));
while ( peekLine(in) != null)
{
if (peekLine(in).trim().startsWith("#if"))
{
processIf(in, out, ignoring);
}
else if (peekLine(in).trim().startsWith("#"))
{
break;
}
else
{
String line = getLine(in);
if (!ignoring) write(out, line);
}
}
out.flush();
}
private void processIf(BufferedReader in, PrintWriter out, boolean ignoring) throws IOException
{
String line = getLine(in).trim();
assert line.trim().startsWith("#if");
boolean foundTrueCondition = false;
boolean condition = evaluate(line.substring(3).trim());
while (true)
{
process(in, out, ignoring || foundTrueCondition || !condition);
foundTrueCondition |= condition;
if (peekLine(in) == null || !peekLine(in).trim().startsWith("#elif"))
break;
condition = evaluate(getLine(in).trim().substring(5).trim());
}
if (peekLine(in) != null && peekLine(in).trim().startsWith("#else"))
{
getLine(in); // Discard the #else line
process(in, out, ignoring || foundTrueCondition);
}
line = getLine(in);
if (line == null)
throw new IOException("Missing \"#fi\"");
if (!line.trim().startsWith("#fi"))
throw new IOException("Expected \"#fi\", got: " + line);
}
public static void main(String[] args) throws Exception
{
Map map = new HashMap();
map.put("falseArg", Boolean.FALSE);
map.put("trueArg", Boolean.TRUE);
map.put("stringValue", "someString");
new OutputFileGenerator(args[0], map).generate(new PrintWriter(args[1]));
}
public static void generateFromTemplate(
String template, Map options,
String outputFileName) throws IOException {
OutputFileGenerator gen = new OutputFileGenerator(template, options);
StringWriter sw = new StringWriter();
gen.generate(new PrintWriter(sw));
sw.close();
PrintWriter fw = null;
try {
File tmp = new File(outputFileName);
fw = new PrintWriter(
new BufferedWriter(
new FileWriter(tmp),
8092
)
);
fw.print(sw.toString());
} finally {
if (fw != null) {
fw.close();
}
}
}
}