/*
* Encog(tm) Core v3.3 - Java Version
* http://www.heatonresearch.com/encog/
* https://github.com/encog/encog-java-core
* Copyright 2008-2014 Heaton Research, Inc.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package org.encog.parse.expression.epl;
import java.util.StringTokenizer;
import org.encog.ml.ea.exception.EACompileError;
import org.encog.ml.prg.EncogProgram;
import org.encog.ml.prg.ProgramNode;
import org.encog.ml.prg.expvalue.ExpressionValue;
import org.encog.ml.prg.extension.EncogOpcodeRegistry;
import org.encog.ml.prg.extension.ProgramExtensionTemplate;
import org.encog.util.SimpleParser;
import org.encog.util.csv.CSVFormat;
import org.encog.util.datastruct.StackObject;
/**
* Parse an EPL string.
*/
public class ParseEPL {
private final EncogProgram holder;
private SimpleParser parser;
private StackObject<ProgramNode> nodeStack = new StackObject<ProgramNode>(100);
public ParseEPL(final EncogProgram theHolder) {
this.holder = theHolder;
}
public ProgramNode parse(final String expression) {
this.parser = new SimpleParser(expression);
while(!this.parser.eol()) {
this.parser.eatWhiteSpace();
// read in the command
if( this.parser.readChar()!='[' ) {
throw new EACompileError("Expected [");
}
this.parser.eatWhiteSpace();
StringBuilder cmd = new StringBuilder();
while(this.parser.peek()!=']' && !this.parser.eol()) {
cmd.append(this.parser.readChar());
}
if( this.parser.peek()!=']') {
throw new EACompileError("Expected ]");
}
this.parser.advance();
// parse out the command
StringTokenizer tok = new StringTokenizer(cmd.toString(),":");
String name = tok.nextToken();
int childCount = Integer.parseInt(tok.nextToken());
ProgramExtensionTemplate temp = EncogOpcodeRegistry.INSTANCE.findOpcode(name, childCount);
if( temp==null ) {
throw new EACompileError("Invalid instruction: " + name);
}
// build the arguments
ProgramNode[] args = new ProgramNode[childCount];
for(int i=args.length-1;i>=0;i--) {
args[i] = this.nodeStack.pop();
}
// factor the node
ProgramNode node = this.holder.getFunctions().factorProgramNode(name, this.holder, args);
this.nodeStack.push(node);
// add any needed data to the node
for(int i=0;i<temp.getDataSize();i++) {
String str = tok.nextToken().trim();
int idx = str.indexOf('#');
if( idx!=-1) {
int enumType = Integer.parseInt(str.substring(0,idx));
int enumVal = Integer.parseInt(str.substring(idx+1));
node.getData()[0] = new ExpressionValue(enumType,enumVal);
}
// is it boolean?
else if( str.length()==1 && "tf".indexOf(Character.toLowerCase(str.charAt(0)))!=-1 ) {
node.getData()[i] = new ExpressionValue(str.equalsIgnoreCase("t"));
}
// is it a string?
else if( str.charAt(0)=='\"' ) {
node.getData()[i] = new ExpressionValue(str.substring(1,str.length()-1));
}
// is it an integer
else if( str.indexOf('.')==-1 && str.toLowerCase().indexOf('e')==-1) {
long l;
try {
l = Long.parseLong(str);
} catch(NumberFormatException ex) {
// sometimes Java will output a long value that is larger than can be parsed
// this is very likely not a useful genome and we just set it to zero so that
// the population load does not fail.
l=0;
}
node.getData()[i] = new ExpressionValue(l);
}
// At this point, must be a float
else {
node.getData()[i] = new ExpressionValue(CSVFormat.EG_FORMAT.parse(str));
}
}
}
return this.nodeStack.pop();
}
}