diff --git a/pom.xml b/pom.xml
index 35df154..339882a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -10,7 +10,7 @@
 	</parent>
 
 	<artifactId>parsington</artifactId>
-	<version>3.1.1-SNAPSHOT</version>
+	<version>3.2.0-SNAPSHOT</version>
 
 	<name>Parsington: The SciJava Expression Parser</name>
 	<description>A general-purpose mathematical expression parser, which converts infix expression strings into postfix queues and/or syntax trees.</description>
diff --git a/src/main/java/org/scijava/parsington/eval/AbstractEvaluator.java b/src/main/java/org/scijava/parsington/eval/AbstractEvaluator.java
index f4099ff..9dc4ae9 100644
--- a/src/main/java/org/scijava/parsington/eval/AbstractEvaluator.java
+++ b/src/main/java/org/scijava/parsington/eval/AbstractEvaluator.java
@@ -30,6 +30,7 @@
 
 package org.scijava.parsington.eval;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -79,6 +80,11 @@ public Object get(final String name) {
 		return new Unresolved(name);
 	}
 
+	@Override
+	public Map<String, Object> getAll() {
+		return Collections.unmodifiableMap(vars);
+	}
+
 	@Override
 	public void set(final String name, final Object value) {
 		vars.put(name, value);
@@ -89,4 +95,14 @@ public void setAll(final Map<? extends String, ? extends Object> map) {
 		vars.putAll(map);
 	}
 
+	@Override
+	public Object remove(final String name) {
+		return vars.remove(name);
+	}
+
+	@Override
+	public void clear() {
+		vars.clear();
+	}
+
 }
diff --git a/src/main/java/org/scijava/parsington/eval/Evaluator.java b/src/main/java/org/scijava/parsington/eval/Evaluator.java
index 3ebf1e9..1be84d2 100644
--- a/src/main/java/org/scijava/parsington/eval/Evaluator.java
+++ b/src/main/java/org/scijava/parsington/eval/Evaluator.java
@@ -167,6 +167,13 @@ default Object get(final Variable v) {
 		return get(v.getToken());
 	}
 
+	/**
+	 * Gets a map of all variable names and values.
+	 *
+	 * @return A map from variable names to variable values.
+	 */
+	Map<String, Object> getAll();
+
 	/**
 	 * Sets the value of a variable.
 	 * 
@@ -184,4 +191,19 @@ default void set(final Variable v, final Object value) {
 	 */
 	void setAll(Map<? extends String, ? extends Object> map);
 
+	/**
+	 * Removes the named variable.
+	 *
+	 * @param name The name of the variable whose value you want to remove.
+	 * @return The previous variables value associated with name,
+	 *         or null if the name did not exist.
+	 */
+	Object remove(String name);
+
+	/**
+	 * Clears all the variables.
+	 *
+	 */
+	void clear();
+
 }
diff --git a/src/test/java/org/scijava/parsington/eval/AbstractEvaluatorTest.java b/src/test/java/org/scijava/parsington/eval/AbstractEvaluatorTest.java
new file mode 100644
index 0000000..62d5fc9
--- /dev/null
+++ b/src/test/java/org/scijava/parsington/eval/AbstractEvaluatorTest.java
@@ -0,0 +1,118 @@
+/*
+ * #%L
+ * Parsington: the SciJava mathematical expression parser.
+ * %%
+ * Copyright (C) 2015 - 2026 Board of Regents of the University of
+ * Wisconsin-Madison.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.parsington.eval;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.scijava.parsington.AbstractTest;
+
+/**
+ * Abstract base class for testing {@link Evaluator} implementations.
+ *
+ * @author Curtis Rueden
+ */
+public abstract class AbstractEvaluatorTest extends AbstractTest {
+
+	public abstract Evaluator createEvaluator();
+
+	/**
+	 * Tests {@link Evaluator#get(String)} and
+	 * {@link Evaluator#set(String, Object)}.
+	 */
+	@Test
+	public void testGetSet() {
+		final Evaluator e = createEvaluator();
+		// In strict mode (the default), getting an unset variable throws.
+		assertThrows(IllegalArgumentException.class, () -> e.get("x"));
+		e.set("x", 42);
+		assertEquals(42, e.get("x"));
+		e.set("x", "hello");
+		assertEquals("hello", e.get("x"));
+	}
+
+	/** Tests {@link Evaluator#remove(String)}. */
+	@Test
+	public void testRemove() {
+		final Evaluator e = createEvaluator();
+		// Removing an absent variable returns null.
+		assertNull(e.remove("x"));
+		e.set("x", 99);
+		assertEquals(99, e.remove("x"));
+		// Variable is gone after removal.
+		assertThrows(IllegalArgumentException.class, () -> e.get("x"));
+	}
+
+	/** Tests {@link Evaluator#clear()}. */
+	@Test
+	public void testClear() {
+		final Evaluator e = createEvaluator();
+		e.set("a", 1);
+		e.set("b", 2);
+		e.clear();
+		assertEquals(new HashMap<>(), e.getAll());
+		assertThrows(IllegalArgumentException.class, () -> e.get("a"));
+		assertThrows(IllegalArgumentException.class, () -> e.get("b"));
+	}
+
+	/** Tests {@link Evaluator#getAll()} and {@link Evaluator#setAll(Map)}. */
+	@Test
+	public void testGetAllSetAll() {
+		final Evaluator e = createEvaluator();
+		assertEquals(new HashMap<>(), e.getAll());
+
+		final Map<String, Object> vars = new HashMap<>();
+		vars.put("a", 1);
+		vars.put("b", "two");
+		vars.put("c", 3.0);
+		e.setAll(vars);
+
+		assertEquals(vars, e.getAll());
+
+		// Verify individual get still works after setAll.
+		assertEquals(1, e.get("a"));
+		assertEquals("two", e.get("b"));
+		assertEquals(3.0, e.get("c"));
+
+		// Verify variables created at evaluation are accessible and correct.
+		e.evaluate("d=a+c");
+		assertTrue(e.getAll().containsKey("d"));
+		final Object dVal = e.get("d");
+		assertEquals(4.0, dVal);
+		assertEquals(dVal, e.getAll().get("d"));
+	}
+}
diff --git a/src/test/java/org/scijava/parsington/eval/AbstractStandardEvaluatorTest.java b/src/test/java/org/scijava/parsington/eval/AbstractStandardEvaluatorTest.java
index f1a2955..7476c8c 100644
--- a/src/test/java/org/scijava/parsington/eval/AbstractStandardEvaluatorTest.java
+++ b/src/test/java/org/scijava/parsington/eval/AbstractStandardEvaluatorTest.java
@@ -45,13 +45,12 @@
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.scijava.parsington.AbstractTest;
 import org.scijava.parsington.Operators;
 import org.scijava.parsington.SyntaxTree;
 import org.scijava.parsington.Variable;
 
 /** Abstract base class for testing {@link StandardEvaluator} implementations. */
-public abstract class AbstractStandardEvaluatorTest extends AbstractTest {
+public abstract class AbstractStandardEvaluatorTest extends AbstractEvaluatorTest {
 
 	protected StandardEvaluator e;
 
@@ -60,6 +59,7 @@ public void setUp() {
 		e = createEvaluator();
 	}
 
+	@Override
 	public abstract StandardEvaluator createEvaluator();
 
 	/** Tests {@link Evaluator#evaluate(String)}. */