Minor changes

17 files changed, 235 insertions, 15 deletions

diff --git a/JPratt/.settings/org.eclipse.jdt.core.prefs b/JPratt/.settings/org.eclipse.jdt.core.prefs
index cf2cd45..40089f4 100644
--- a/JPratt/.settings/org.eclipse.jdt.core.prefs
+++ b/JPratt/.settings/org.eclipse.jdt.core.prefs
@@ -1,8 +1,110 @@
 eclipse.preferences.version=1
+org.eclipse.jdt.core.builder.annotationPath.allLocations=disabled
+org.eclipse.jdt.core.compiler.annotation.inheritNullAnnotations=disabled
+org.eclipse.jdt.core.compiler.annotation.missingNonNullByDefaultAnnotation=ignore
+org.eclipse.jdt.core.compiler.annotation.nonnull=org.eclipse.jdt.annotation.NonNull
+org.eclipse.jdt.core.compiler.annotation.nonnull.secondary=
+org.eclipse.jdt.core.compiler.annotation.nonnullbydefault=org.eclipse.jdt.annotation.NonNullByDefault
+org.eclipse.jdt.core.compiler.annotation.nonnullbydefault.secondary=
+org.eclipse.jdt.core.compiler.annotation.nullable=org.eclipse.jdt.annotation.Nullable
+org.eclipse.jdt.core.compiler.annotation.nullable.secondary=
+org.eclipse.jdt.core.compiler.annotation.nullanalysis=disabled
 org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
 org.eclipse.jdt.core.compiler.compliance=17
+org.eclipse.jdt.core.compiler.problem.APILeak=warning
+org.eclipse.jdt.core.compiler.problem.annotatedTypeArgumentToUnannotated=info
+org.eclipse.jdt.core.compiler.problem.annotationSuperInterface=warning
+org.eclipse.jdt.core.compiler.problem.autoboxing=ignore
+org.eclipse.jdt.core.compiler.problem.comparingIdentical=warning
+org.eclipse.jdt.core.compiler.problem.deadCode=warning
+org.eclipse.jdt.core.compiler.problem.deprecation=warning
+org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
+org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=disabled
+org.eclipse.jdt.core.compiler.problem.discouragedReference=warning
+org.eclipse.jdt.core.compiler.problem.emptyStatement=ignore
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
+org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=info
+org.eclipse.jdt.core.compiler.problem.fallthroughCase=ignore
+org.eclipse.jdt.core.compiler.problem.fatalOptionalError=disabled
+org.eclipse.jdt.core.compiler.problem.fieldHiding=info
+org.eclipse.jdt.core.compiler.problem.finalParameterBound=warning
+org.eclipse.jdt.core.compiler.problem.finallyBlockNotCompletingNormally=warning
 org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
+org.eclipse.jdt.core.compiler.problem.hiddenCatchBlock=warning
+org.eclipse.jdt.core.compiler.problem.includeNullInfoFromAsserts=disabled
+org.eclipse.jdt.core.compiler.problem.incompatibleNonInheritedInterfaceMethod=warning
+org.eclipse.jdt.core.compiler.problem.incompleteEnumSwitch=warning
+org.eclipse.jdt.core.compiler.problem.indirectStaticAccess=ignore
+org.eclipse.jdt.core.compiler.problem.localVariableHiding=info
+org.eclipse.jdt.core.compiler.problem.methodWithConstructorName=warning
+org.eclipse.jdt.core.compiler.problem.missingDefaultCase=info
+org.eclipse.jdt.core.compiler.problem.missingDeprecatedAnnotation=ignore
+org.eclipse.jdt.core.compiler.problem.missingEnumCaseDespiteDefault=disabled
+org.eclipse.jdt.core.compiler.problem.missingHashCodeMethod=info
+org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotation=ignore
+org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotationForInterfaceMethodImplementation=enabled
+org.eclipse.jdt.core.compiler.problem.missingSerialVersion=warning
+org.eclipse.jdt.core.compiler.problem.missingSynchronizedOnInheritedMethod=ignore
+org.eclipse.jdt.core.compiler.problem.noEffectAssignment=warning
+org.eclipse.jdt.core.compiler.problem.noImplicitStringConversion=warning
+org.eclipse.jdt.core.compiler.problem.nonExternalizedStringLiteral=ignore
+org.eclipse.jdt.core.compiler.problem.nonnullParameterAnnotationDropped=warning
+org.eclipse.jdt.core.compiler.problem.nonnullTypeVariableFromLegacyInvocation=warning
+org.eclipse.jdt.core.compiler.problem.nullAnnotationInferenceConflict=error
+org.eclipse.jdt.core.compiler.problem.nullReference=warning
+org.eclipse.jdt.core.compiler.problem.nullSpecViolation=error
+org.eclipse.jdt.core.compiler.problem.nullUncheckedConversion=warning
+org.eclipse.jdt.core.compiler.problem.overridingPackageDefaultMethod=warning
+org.eclipse.jdt.core.compiler.problem.parameterAssignment=warning
+org.eclipse.jdt.core.compiler.problem.pessimisticNullAnalysisForFreeTypeVariables=warning
+org.eclipse.jdt.core.compiler.problem.possibleAccidentalBooleanAssignment=ignore
+org.eclipse.jdt.core.compiler.problem.potentialNullReference=ignore
+org.eclipse.jdt.core.compiler.problem.potentiallyUnclosedCloseable=ignore
+org.eclipse.jdt.core.compiler.problem.rawTypeReference=warning
+org.eclipse.jdt.core.compiler.problem.redundantNullAnnotation=warning
+org.eclipse.jdt.core.compiler.problem.redundantNullCheck=ignore
+org.eclipse.jdt.core.compiler.problem.redundantSpecificationOfTypeArguments=info
+org.eclipse.jdt.core.compiler.problem.redundantSuperinterface=ignore
+org.eclipse.jdt.core.compiler.problem.reportMethodCanBePotentiallyStatic=ignore
+org.eclipse.jdt.core.compiler.problem.reportMethodCanBeStatic=info
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
+org.eclipse.jdt.core.compiler.problem.specialParameterHidingField=disabled
+org.eclipse.jdt.core.compiler.problem.staticAccessReceiver=warning
+org.eclipse.jdt.core.compiler.problem.suppressOptionalErrors=disabled
+org.eclipse.jdt.core.compiler.problem.suppressWarnings=enabled
+org.eclipse.jdt.core.compiler.problem.suppressWarningsNotFullyAnalysed=info
+org.eclipse.jdt.core.compiler.problem.syntacticNullAnalysisForFields=disabled
+org.eclipse.jdt.core.compiler.problem.syntheticAccessEmulation=ignore
+org.eclipse.jdt.core.compiler.problem.terminalDeprecation=warning
+org.eclipse.jdt.core.compiler.problem.typeParameterHiding=warning
+org.eclipse.jdt.core.compiler.problem.unavoidableGenericTypeProblems=disabled
+org.eclipse.jdt.core.compiler.problem.uncheckedTypeOperation=warning
+org.eclipse.jdt.core.compiler.problem.unclosedCloseable=warning
+org.eclipse.jdt.core.compiler.problem.undocumentedEmptyBlock=ignore
+org.eclipse.jdt.core.compiler.problem.unhandledWarningToken=warning
+org.eclipse.jdt.core.compiler.problem.unlikelyCollectionMethodArgumentType=warning
+org.eclipse.jdt.core.compiler.problem.unlikelyCollectionMethodArgumentTypeStrict=disabled
+org.eclipse.jdt.core.compiler.problem.unlikelyEqualsArgumentType=info
+org.eclipse.jdt.core.compiler.problem.unnecessaryElse=info
+org.eclipse.jdt.core.compiler.problem.unnecessaryTypeCheck=info
+org.eclipse.jdt.core.compiler.problem.unqualifiedFieldAccess=ignore
+org.eclipse.jdt.core.compiler.problem.unstableAutoModuleName=warning
+org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownException=info
+org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionExemptExceptionAndThrowable=enabled
+org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionIncludeDocCommentReference=enabled
+org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionWhenOverriding=disabled
+org.eclipse.jdt.core.compiler.problem.unusedExceptionParameter=ignore
+org.eclipse.jdt.core.compiler.problem.unusedImport=warning
+org.eclipse.jdt.core.compiler.problem.unusedLabel=warning
+org.eclipse.jdt.core.compiler.problem.unusedLocal=warning
+org.eclipse.jdt.core.compiler.problem.unusedObjectAllocation=ignore
+org.eclipse.jdt.core.compiler.problem.unusedParameter=ignore
+org.eclipse.jdt.core.compiler.problem.unusedParameterIncludeDocCommentReference=enabled
+org.eclipse.jdt.core.compiler.problem.unusedParameterWhenImplementingAbstract=disabled
+org.eclipse.jdt.core.compiler.problem.unusedParameterWhenOverridingConcrete=disabled
+org.eclipse.jdt.core.compiler.problem.unusedPrivateMember=warning
+org.eclipse.jdt.core.compiler.problem.unusedTypeParameter=ignore
+org.eclipse.jdt.core.compiler.problem.unusedWarningToken=warning
+org.eclipse.jdt.core.compiler.problem.varargsArgumentNeedCast=warning
 org.eclipse.jdt.core.compiler.release=disabled
 org.eclipse.jdt.core.compiler.source=17
diff --git a/JPratt/src/examples/java/bjc/pratt/examples/lang/PrattParserTest.java b/JPratt/src/examples/java/bjc/pratt/examples/lang/PrattParserTest.java
index 9d05ca2..ac5aa12 100644
--- a/JPratt/src/examples/java/bjc/pratt/examples/lang/PrattParserTest.java
+++ b/JPratt/src/examples/java/bjc/pratt/examples/lang/PrattParserTest.java
@@ -33,7 +33,6 @@ import bjc.pratt.commands.NonInitialCommand;
 import bjc.pratt.tokens.StringToken;
 import bjc.pratt.tokens.StringTokenStream;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.data.TransformIterator;
 import bjc.funcdata.ListEx;
 import bjc.utils.parserutils.ParserException;
diff --git a/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java b/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java
index 3f79665..b0a3844 100644
--- a/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java
+++ b/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java
@@ -5,7 +5,6 @@ import java.util.function.Function;
 import bjc.pratt.ParserContext;
 import bjc.pratt.PrattParser;
 import bjc.pratt.commands.CommandResult;
-import bjc.pratt.commands.CommandResult.Status;
 import bjc.pratt.tokens.Token;
 import bjc.pratt.tokens.TokenStream;
 import bjc.data.Tree;
diff --git a/JPratt/src/main/java/bjc/pratt/blocks/ParseBlock.java b/JPratt/src/main/java/bjc/pratt/blocks/ParseBlock.java
index fede096..aa2fa2e 100644
--- a/JPratt/src/main/java/bjc/pratt/blocks/ParseBlock.java
+++ b/JPratt/src/main/java/bjc/pratt/blocks/ParseBlock.java
@@ -2,8 +2,6 @@ package bjc.pratt.blocks;
 
 import bjc.pratt.ParserContext;
 import bjc.pratt.commands.CommandResult;
-import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/blocks/TriggeredParseBlock.java b/JPratt/src/main/java/bjc/pratt/blocks/TriggeredParseBlock.java
index df17595..d404eea 100644
--- a/JPratt/src/main/java/bjc/pratt/blocks/TriggeredParseBlock.java
+++ b/JPratt/src/main/java/bjc/pratt/blocks/TriggeredParseBlock.java
@@ -5,8 +5,6 @@ import java.util.function.UnaryOperator;
 import bjc.pratt.ParserContext;
 import bjc.pratt.commands.CommandResult;
 import bjc.pratt.commands.CommandResult.Status;
-import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/commands/AbstractInitialCommand.java b/JPratt/src/main/java/bjc/pratt/commands/AbstractInitialCommand.java
index 48f9ba7..3e4f3a9 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/AbstractInitialCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/AbstractInitialCommand.java
@@ -2,7 +2,6 @@ package bjc.pratt.commands;
 
 import bjc.pratt.ParserContext;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/commands/InitialCommand.java b/JPratt/src/main/java/bjc/pratt/commands/InitialCommand.java
index ba544b4..0cfa290 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/InitialCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/InitialCommand.java
@@ -2,7 +2,6 @@ package bjc.pratt.commands;
 
 import bjc.pratt.ParserContext;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/BlockInitialCommand.java b/JPratt/src/main/java/bjc/pratt/commands/impls/BlockInitialCommand.java
index 1d54996..07d9a76 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/impls/BlockInitialCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/BlockInitialCommand.java
@@ -5,7 +5,6 @@ import bjc.pratt.blocks.ParseBlock;
 import bjc.pratt.commands.AbstractInitialCommand;
 import bjc.pratt.commands.CommandResult;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/DefaultInitialCommand.java b/JPratt/src/main/java/bjc/pratt/commands/impls/DefaultInitialCommand.java
index 2dfc576..8d28b57 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/impls/DefaultInitialCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/DefaultInitialCommand.java
@@ -4,7 +4,6 @@ import bjc.pratt.ParserContext;
 import bjc.pratt.commands.CommandResult;
 import bjc.pratt.commands.InitialCommand;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/DenestingCommand.java b/JPratt/src/main/java/bjc/pratt/commands/impls/DenestingCommand.java
index 4935c81..de39e0b 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/impls/DenestingCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/DenestingCommand.java
@@ -6,7 +6,6 @@ import bjc.pratt.commands.CommandResult;
 import bjc.pratt.commands.CommandResult.Status;
 import bjc.pratt.commands.InitialCommand;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.utils.parserutils.ParserException;
 
 /**
diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/InitialCommands.java b/JPratt/src/main/java/bjc/pratt/commands/impls/InitialCommands.java
index 9801788..bfc4e4f 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/impls/InitialCommands.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/InitialCommands.java
@@ -9,8 +9,6 @@ import java.util.function.UnaryOperator;
 import bjc.pratt.blocks.ParseBlock;
 import bjc.pratt.commands.InitialCommand;
 import bjc.pratt.tokens.Token;
-import bjc.utils.parserutils.ParserException;
-import bjc.data.SimpleTree;
 import bjc.data.Tree;
 
 /**
@@ -211,6 +209,6 @@ public class InitialCommands {
 	 * @return A command that implements a panfix operator
 	 */
 	public static <K, V, C> InitialCommand<K, V, C> panfix(final int precedence, final K term, final Token<K, V> marker) {
-		return new PanfixCommand<K, V, C>(marker, term, precedence);
+		return new PanfixCommand<>(marker, term, precedence);
 	}
 }
\ No newline at end of file
diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/LeafCommand.java b/JPratt/src/main/java/bjc/pratt/commands/impls/LeafCommand.java
index c702323..20fb3d4 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/impls/LeafCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/LeafCommand.java
@@ -4,7 +4,6 @@ import bjc.pratt.ParserContext;
 import bjc.pratt.commands.CommandResult;
 import bjc.pratt.commands.InitialCommand;
 import bjc.pratt.tokens.Token;
-import bjc.data.Tree;
 import bjc.data.SimpleTree;
 import bjc.utils.parserutils.ParserException;
 
diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java b/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java
index 06e69c1..04ad370 100644
--- a/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java
@@ -9,11 +9,26 @@ import bjc.pratt.commands.CommandResult.Status;
 import bjc.pratt.tokens.Token;
 import bjc.utils.parserutils.ParserException;
 
+/**
+ * Represents a 'panfix' command, one where the operator is repeated prefix, infix and postfix.
+ * @author bjcul
+ *
+ * @param <K> The key type of the token
+ * @param <V> The value type of the token
+ * @param <C> The context type of the parser
+ */
 public final class PanfixCommand<K, V, C> implements InitialCommand<K, V, C> {
 	private final Token<K, V> marker;
 	private final K term;
 	private final int precedence;
 
+	/**
+	 * Create a new panfix command.
+	 * 
+	 * @param marker The marker token.
+	 * @param term The value to use as the root of the result-tree
+	 * @param precedence The precedence for this command
+	 */
 	public PanfixCommand(Token<K, V> marker, K term, int precedence) {
 		this.marker = marker;
 		this.term = term;
diff --git a/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java b/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java
index 8c7fcec..70876f2 100644
--- a/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java
+++ b/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java
@@ -33,6 +33,9 @@ public class StringTokenStream extends TokenStream<String, String> {
 
 	@Override
 	public Token<String, String> current() {
+		// Prime stream if necessary
+		if (curr == null)
+			return next();
 		return curr;
 	}
 
@@ -70,6 +73,8 @@ public class StringTokenStream extends TokenStream<String, String> {
 	@Override
 	public void rollback() {
 		iter.rollback();
+		
+		curr = iter.current();
 	}
 	
 	@Override
diff --git a/JPratt/src/test/java/bjc/test/pratt/PrattParserTest.java b/JPratt/src/test/java/bjc/test/pratt/PrattParserTest.java
new file mode 100644
index 0000000..608a137
--- /dev/null
+++ b/JPratt/src/test/java/bjc/test/pratt/PrattParserTest.java
@@ -0,0 +1,58 @@
+package bjc.test.pratt;
+
+import static org.junit.Assert.*;
+import static bjc.test.pratt.TestUtils.*;
+
+import java.util.Iterator;
+
+import org.junit.Test;
+
+import bjc.data.ArrayIterator;
+import bjc.data.SimpleTree;
+import bjc.data.Tree;
+import bjc.pratt.PrattParser;
+import bjc.pratt.commands.CommandResult;
+import bjc.pratt.commands.impls.InitialCommands;
+import bjc.pratt.commands.impls.NonInitialCommands;
+import bjc.pratt.tokens.StringTokenStream;
+import bjc.pratt.tokens.Token;
+import bjc.utils.parserutils.ParserException;
+
+@SuppressWarnings("javadoc")
+public class PrattParserTest {
+
+	@Test
+	public void test() {
+		Iterator<Token<String, String>> iter = new ArrayIterator<>(token("(int)", "1"), token("+"),
+				token("(int)", "2"));
+		StringTokenStream tokens = new StringTokenStream(iter);
+
+		PrattParser<String, String, TestState> parser = new PrattParser<>();
+
+		parser.addInitialCommand("(int)", InitialCommands.leaf());
+		parser.addNonInitialCommand("+", NonInitialCommands.infixLeft(1));
+
+		try {			
+			TestState state = new TestState();
+			
+			tokens.mark();
+			CommandResult<String, String> result = parser.parseExpression(0, tokens, state, false);
+			tokens.rollback();
+			
+			assertEquals(CommandResult.Status.SUCCESS, result.status);
+			Tree<Token<String, String>> actualTree = result.success();
+
+			Tree<Token<String, String>> expectedTree = new SimpleTree<>(token("+"),
+					new SimpleTree<>(token("(int)", "1")), new SimpleTree<>(token("(int)", "2")));
+			
+			assertEquals(expectedTree, actualTree);
+		} catch (ParserException e) {
+			e.printStackTrace();
+		}
+	}
+
+}
+
+class TestState {
+
+}
diff --git a/JPratt/src/test/java/bjc/test/pratt/TestUtils.java b/JPratt/src/test/java/bjc/test/pratt/TestUtils.java
new file mode 100644
index 0000000..a32349f
--- /dev/null
+++ b/JPratt/src/test/java/bjc/test/pratt/TestUtils.java
@@ -0,0 +1,15 @@
+package bjc.test.pratt;
+
+import bjc.pratt.tokens.StringToken;
+import bjc.pratt.tokens.Token;
+
+public class TestUtils {
+
+	public static Token<String, String> token(String val) {
+		return token(val, val);
+	}
+	
+	public static Token<String, String> token(String key, String val) {
+		return new StringToken(key, val);
+	}
+}
diff --git a/JPratt/src/test/java/bjc/test/pratt/tokens/StringTokenStreamTest.java b/JPratt/src/test/java/bjc/test/pratt/tokens/StringTokenStreamTest.java
new file mode 100644
index 0000000..5bacac7
--- /dev/null
+++ b/JPratt/src/test/java/bjc/test/pratt/tokens/StringTokenStreamTest.java
@@ -0,0 +1,39 @@
+package bjc.test.pratt.tokens;
+
+import static org.junit.Assert.*;
+import static bjc.test.pratt.TestUtils.*;
+
+import java.util.Iterator;
+
+import org.junit.Test;
+
+import bjc.data.ArrayIterator;
+import bjc.pratt.tokens.StringTokenStream;
+import bjc.pratt.tokens.Token;
+
+@SuppressWarnings("javadoc")
+public class StringTokenStreamTest {
+
+	@Test
+	public void test() {
+		Token<String, String> tokenA = token("a");
+		Token<String, String> tokenB = token("b");
+		Token<String, String> tokenC = token("c");
+		Token<String, String> tokenD = token("d");
+		
+		Iterator<Token<String, String>> itr = new ArrayIterator<>(tokenA, tokenB, tokenC, tokenD);
+		StringTokenStream strm = new StringTokenStream(itr);
+		
+		assertNull(strm.current());
+		assertEquals(tokenA, strm.next());
+		assertEquals(tokenB, strm.next());
+		strm.mark();
+		assertEquals(tokenC, strm.next());
+		assertEquals(tokenD, strm.next());
+		strm.rollback();
+		assertEquals(tokenC, strm.next());
+		assertEquals(tokenD, strm.next());
+		assertEquals(token("(end)"), strm.next());
+	}
+
+}