Merge commit '42b2e5ca519766e37ce6941ba4faecc9691cc403' into upstream

[debian/openrocket] / core / src / de / congrace / exp4j / CommandlineInterpreter.java

diff --git a/core/src/de/congrace/exp4j/CommandlineInterpreter.java b/core/src/de/congrace/exp4j/CommandlineInterpreter.java
new file mode 100644 (file)
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+++ b/core/src/de/congrace/exp4j/CommandlineInterpreter.java
@@ -0,0 +1,59 @@
+/*
+   Copyright 2011 frank asseg
+
+   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.
+
+ */
+package de.congrace.exp4j;
+
+/**
+ * Simple commandline interpreter for mathematical expressions the interpreter
+ * takes a mathematical expressions as a {@link String} argument, evaluates it
+ * and prints out the result.
+ * 
+ * 
+ * <pre>
+ * java de.congrace.exp4j.CommandlineInterpreter "2 * log(2.2223) - ((2-3.221) * 14.232^2)"
+ * > 248.91042049521056
+ * </pre>
+ * 
+ * @author fas@congrace.de
+ * 
+ */
+public class CommandlineInterpreter {
+       private static void calculateExpression(String string) {
+               try {
+                       final PostfixExpression pe = PostfixExpression.fromInfix(string);
+                       System.out.println(pe.calculate());
+               } catch (UnparsableExpressionException e) {
+                       e.printStackTrace();
+               } catch (UnknownFunctionException e) {
+                       e.printStackTrace();
+               }
+       }
+
+       public static void main(String[] args) {
+               if (args.length != 1) {
+                       printUsage();
+               } else {
+                       calculateExpression(args[0]);
+               }
+       }
+
+       private static void printUsage() {
+               final StringBuilder usage = new StringBuilder();
+               usage.append("Commandline Expression Parser\n\n").append("Example: ").append("\n").append("java -jar exp4j.jar \"2.12 * log(23) * (12 - 4)\"\n\n")
+                               .append("written by fas@congrace.de");
+               System.err.println(usage.toString());
+       }
+}