From b453ec0047b5a87e36098b3519e085f03d917d81 Mon Sep 17 00:00:00 2001
From: Ben Culkin <scorpress@gmail.com>
Date: Sat, 28 Mar 2020 12:02:32 -0400
Subject: Add DualExprParser

This class parses DualExprs from prefix expressions
---
 .../bjc/utils/test/math/DualExprParserTest.java    | 132 +++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 base/src/test/java/bjc/utils/test/math/DualExprParserTest.java

(limited to 'base/src/test/java')

diff --git a/base/src/test/java/bjc/utils/test/math/DualExprParserTest.java b/base/src/test/java/bjc/utils/test/math/DualExprParserTest.java
new file mode 100644
index 0000000..1960b53
--- /dev/null
+++ b/base/src/test/java/bjc/utils/test/math/DualExprParserTest.java
@@ -0,0 +1,132 @@
+package bjc.utils.test.math;
+
+import static org.junit.Assert.*;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
+
+import bjc.utils.exceptions.NonConstantPower;
+import bjc.utils.exceptions.OperandsRemaining;
+import bjc.utils.math.Dual;
+import bjc.utils.math.DualExpr;
+import bjc.utils.math.DualExprParser;
+import bjc.utils.math.DualExprParser.Result;
+
+public class DualExprParserTest {
+
+	@Test
+	public void testBasics() {
+		assertDEEvalsTo(new Dual(1.0, 0.0), "1");
+	}
+	
+	@Test
+	public void testMath() {
+		assertDEEvalsTo(new Dual(2.0, 0.0), "1 1 +");
+		assertDEEvalsTo(new Dual(-1.0, 0.0), "1 2 -");
+		assertDEEvalsTo(new Dual(4.0, 0.0), "2 2 *");
+		assertDEEvalsTo(new Dual(2.0, 0.0), "4 2 /");
+	}
+	
+	@Test
+	public void testFuncs() {
+		assertDEEvalsTo(new Dual(2.0, -0.0), "-2 abs");
+		
+		
+		assertDEEvalsTo(new Dual(Math.sin(2), -0.0), "2 sin");
+		assertDEEvalsTo(new Dual(Math.cos(2), -0.0), "2 cos");
+		
+		assertDEEvalsTo(new Dual(Math.log(2.0), 0.0), "2 log");
+		assertDEEvalsTo(new Dual(Math.exp(2), 0.0), "2 exp");
+
+		assertDEEvalsTo(new Dual(Math.sqrt(2), 0.0), "2 0.5 pow");
+		assertDEEvalsTo(new Dual(4.0, 0.0), "2 2 pow");
+		
+		assertDEEvalsTo(new Dual(4.0, 0.0), "1 2 + eval 1 +");
+	}
+	
+	@Test
+	public void testVars() {
+		assertDEEvalsTo(new Dual(2.0, 0.0), "x x +", "x", 1);
+		
+		assertDEEvalsTo(new Dual(4.0, 4.0), "x 2 pow", "x", new Dual(2.0, 1.0));
+		assertDEEvalsTo(new Dual(8.0, 12.0), "x 3 pow", "x", new Dual(2.0, 1.0));
+	}
+	
+	@Test(expected = IllegalArgumentException.class)
+	public void testDivZero() {
+		assertDEEvalsTo(new Dual(0.0, 0.0), "1 0 /");
+	}
+	
+	@Test(expected = OperandsRemaining.class)
+	public void testOpsRemaining() {
+		DualExprParser.parseExpression("1 2");
+		
+		assertFalse("Shouldn't reach here", true);
+	}
+	
+	@Test(expected = NonConstantPower.class)
+	public void testNonConstantPower() {
+		DualExprParser.parseExpression("1 1 1 dual pow");
+	}
+	
+	private static void assertDEEvalsTo(Dual res, String inp) {
+		assertDEEvalsTo(false, res, inp);
+	}
+	
+	private static void assertDEEvalsTo(Dual res, String inp, Object... vars) {
+		assertDEEvalsTo(false, res, inp, vars);
+	}
+	
+	private static void assertDEEvalsTo(boolean printExpr, Dual res, String inp, Object... vars) {
+		Map<String, DualExpr> varMap = new HashMap<>();
+		
+		for (int idx = 0; idx < vars.length; idx += 2) {
+			if (!(vars[idx] instanceof String)) {
+				throw new IllegalArgumentException("Expected string for variable name");
+			}
+			
+			String name = (String) vars[idx];
+			
+			DualExpr val;
+			Object tentVal = vars[idx + 1];
+			
+			if (tentVal instanceof Integer) {
+				int vl = (int) tentVal;
+				
+				val = new DualExpr(new Dual(vl));
+			} else if (tentVal instanceof Double) {
+				double vl = (double) tentVal;
+				
+				val = new DualExpr(new Dual(vl));
+			} else if (tentVal instanceof Dual) {
+				val = new DualExpr((Dual) tentVal);
+			} else if (tentVal instanceof DualExpr) {
+				val = (DualExpr) tentVal;
+			} else {
+				throw new IllegalArgumentException("Invalid argument type " + tentVal.getClass().getName());
+			}
+			
+			varMap.put(name, val);
+		}
+		
+		Result res1 = DualExprParser.parseExpression(inp, varMap);
+		
+		DualExpr de1 = res1.expr;
+		
+		if (printExpr) System.out.printf("Expression: '%s'\n", de1);
+		
+		assertEquals(res, de1.evaluate());
+	}
+	
+	private static void assertDEEvalsTo(boolean printExpr, Dual res, String inp) {
+		Result res1 = DualExprParser.parseExpression(inp);
+		
+		DualExpr de1 = res1.expr;
+		
+		if (printExpr) System.out.printf("Expression: '%s'\n", de1);
+		
+		assertEquals(res, de1.evaluate());
+	}
+}
\ No newline at end of file
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