org.codehaus.groovy.ast.tools.ClosureUtils Maven / Gradle / Ivy
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package org.codehaus.groovy.ast.tools;
import org.codehaus.groovy.ast.expr.ClosureExpression;
import org.codehaus.groovy.control.io.ReaderSource;
/**
* Handy methods when working with the Closure expressions.
*
* @author Hamlet D'Arcy
* @author Sergei Egorov
*/
public class ClosureUtils {
/**
* Converts a ClosureExpression into the String source.
*
* @param readerSource a source
* @param expression a closure. Can't be null
* @return the source the closure was created from
* @throws java.lang.IllegalArgumentException when expression is null
* @throws java.lang.Exception when closure can't be read from source
*/
public static String convertClosureToSource(ReaderSource readerSource, ClosureExpression expression) throws Exception {
if (expression == null) throw new IllegalArgumentException("Null: expression");
StringBuilder result = new StringBuilder();
for (int x = expression.getLineNumber(); x <= expression.getLastLineNumber(); x++) {
String line = readerSource.getLine(x, null);
if (line == null) {
throw new Exception(
"Error calculating source code for expression. Trying to read line " + x + " from " + readerSource.getClass()
);
}
if (x == expression.getLastLineNumber()) {
line = line.substring(0, expression.getLastColumnNumber() - 1);
}
if (x == expression.getLineNumber()) {
line = line.substring(expression.getColumnNumber() - 1);
}
//restoring line breaks is important b/c of lack of semicolons
result.append(line).append('\n');
}
String source = result.toString().trim();
if (!source.startsWith("{")) {
throw new Exception("Error converting ClosureExpression into source code. Closures must start with {. Found: " + source);
}
return source;
}
}