svn-gvsig-desktop / trunk / org.gvsig.desktop / org.gvsig.desktop.library / org.gvsig.expressionevaluator / org.gvsig.expressionevaluator.lib / org.gvsig.expressionevaluator.lib.impl / src / main / java / org / gvsig / expressionevaluator / impl / function / numeric / DecrFunction.java @ 44098
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package org.gvsig.expressionevaluator.impl.function.numeric; |
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import org.apache.commons.lang3.Range; |
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import org.gvsig.expressionevaluator.Interpreter; |
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import org.gvsig.expressionevaluator.MutableSymbolTable; |
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import org.gvsig.expressionevaluator.spi.AbstractFunction; |
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public class DecrFunction extends AbstractFunction { |
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public DecrFunction() {
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super("Numeric", "DECR",Range.between(1,3), |
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"Decrease the value of the indicated identifier and return its value.",
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"Decr({{identifier_name}})",
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new String[]{ |
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"identifier name - the identifier used as counter.",
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"first value - Optional. The value with which the identifier must be initialized in its first use. By default zero",
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"step - Optional. The value used to decrease the identifier. By default one",
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}, |
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"Long",
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false
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); |
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} |
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@Override
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public boolean allowConstantFolding() { |
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return true; |
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} |
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@Override
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public Object call(Interpreter interpreter, Object[] args) { |
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String identifierName = this.getStr(args, 0); |
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long firstValue = 0; |
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long increment = 1; |
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long value;
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switch(args.length) {
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default:
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case 1: |
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break;
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case 2: |
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firstValue = this.getLong(args, 1); |
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break;
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case 3: |
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firstValue = this.getLong(args, 1); |
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increment = this.getLong(args, 2); |
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break;
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} |
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MutableSymbolTable symbolTable = (MutableSymbolTable) interpreter.getSymbolTable(); |
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if( symbolTable.exists(identifierName) ) {
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value = ((Number) symbolTable.value(identifierName)).longValue();
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} else {
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value = firstValue; |
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} |
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value = value-increment; |
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symbolTable.setVar(identifierName, value); |
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return value;
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} |
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} |