diff --git a/src/main/java/org/scijava/parsington/ExpressionParser.java b/src/main/java/org/scijava/parsington/ExpressionParser.java
index eeea692..e8bd630 100644
--- a/src/main/java/org/scijava/parsington/ExpressionParser.java
+++ b/src/main/java/org/scijava/parsington/ExpressionParser.java
@@ -151,15 +151,15 @@ public ExpressionParser(final Collection<? extends Operator> operators,
 
 		// NB: Ensure operators with longer symbols come first.
 		// This prevents e.g. '-' from being matched before '-=' and '--'.
-		Collections.sort(operatorsList, (o1, o2) -> {
-			final String t1 = o1.getToken();
-			final String t2 = o2.getToken();
-			final int len1 = t1.length();
-			final int len2 = t2.length();
-			if (len1 > len2) return -1; // o1 is longer, so o1 comes first.
-			if (len1 < len2) return 1; // o2 is longer, so o2 comes first.
-			return t1.compareTo(t2);
-		});
+		operatorsList.sort((o1, o2) -> {
+            final String t1 = o1.getToken();
+            final String t2 = o2.getToken();
+            final int len1 = t1.length();
+            final int len2 = t2.length();
+            if (len1 > len2) return -1; // o1 is longer, so o1 comes first.
+            if (len1 < len2) return 1; // o2 is longer, so o2 comes first.
+            return t1.compareTo(t2);
+        });
 
 		this.operators = Collections.unmodifiableList(operatorsList);
 		this.elementSeparator = elementSeparator;
diff --git a/src/main/java/org/scijava/parsington/Literals.java b/src/main/java/org/scijava/parsington/Literals.java
index f5997bd..6ac708f 100644
--- a/src/main/java/org/scijava/parsington/Literals.java
+++ b/src/main/java/org/scijava/parsington/Literals.java
@@ -444,11 +444,8 @@ public static Number parseNumber(final CharSequence s, final Position pos) {
 		final Number octal = parseOctal(s, pos);
 		if (octal != null) return octal;
 
-		final Number decimal = parseDecimal(s, pos);
-		if (decimal != null) return decimal;
-
-		return null;
-	}
+        return parseDecimal(s, pos);
+    }
 
 	/**
 	 * Parses a literal of any known type (booleans, strings and numbers).
@@ -472,11 +469,8 @@ public static Object parseLiteral(final CharSequence s, final Position pos) {
 		final String str = parseString(s, pos);
 		if (str != null) return str;
 
-		final Number num = parseNumber(s, pos);
-		if (num != null) return num;
-
-		return null;
-	}
+        return parseNumber(s, pos);
+    }
 
 	// -- Helper methods --
 
@@ -618,8 +612,7 @@ private static boolean isWord(final CharSequence s, final Position pos,
 		if (next >= 'a' && next <= 'z') return false;
 		if (next >= 'A' && next <= 'Z') return false;
 		if (next >= '0' && next <= '9') return false;
-		if (next == '_') return false;
-		return true;
-	}
+        return next != '_';
+    }
 
 }
diff --git a/src/main/java/org/scijava/parsington/SyntaxTree.java b/src/main/java/org/scijava/parsington/SyntaxTree.java
index 3f8bc4b..cf857bd 100644
--- a/src/main/java/org/scijava/parsington/SyntaxTree.java
+++ b/src/main/java/org/scijava/parsington/SyntaxTree.java
@@ -143,7 +143,7 @@ private void postfix(final LinkedList<Object> queue) {
 
 	private String toString(final String prefix) {
 		final StringBuilder sb = new StringBuilder();
-		sb.append(prefix + " '" + token + "'\n");
+		sb.append(prefix).append(" '").append(token).append("'\n");
 		final String deeperPrefix = " " + prefix + "-";
 		for (int i = 0; i < count(); i++) {
 			sb.append(child(i).toString(deeperPrefix));
diff --git a/src/main/java/org/scijava/parsington/Tokens.java b/src/main/java/org/scijava/parsington/Tokens.java
index f0d3d89..17d30ed 100644
--- a/src/main/java/org/scijava/parsington/Tokens.java
+++ b/src/main/java/org/scijava/parsington/Tokens.java
@@ -61,7 +61,7 @@ public static boolean isComma(final Object o) {
 	}
 
 	public static boolean isCharacter(final Object o, final Character c) {
-		return o instanceof Character && ((Character) o).equals(c);
+		return o instanceof Character && o.equals(c);
 	}
 
 	public static boolean isMatchingGroup(final Object o, final Group g) {
diff --git a/src/main/java/org/scijava/parsington/eval/StackEvaluator.java b/src/main/java/org/scijava/parsington/eval/StackEvaluator.java
index 1d0e6ae..55f21ee 100644
--- a/src/main/java/org/scijava/parsington/eval/StackEvaluator.java
+++ b/src/main/java/org/scijava/parsington/eval/StackEvaluator.java
@@ -93,14 +93,14 @@ default Object evaluate(final LinkedList<Object> queue) {
 						"nonary" };
 					final String aryName = arity < aryNames.length ? aryNames[arity]
 						: arity + "-ary";
-					message.append(" " + aryName);
+					message.append(" ").append(aryName);
 				}
 				final String type;
 				if (token instanceof Function) type = "function";
 				else if (token instanceof Group) type = "group";
 				else if (token instanceof Operator) type = "operator";
 				else type = "token";
-				message.append(" " + type + ": " + token);
+				message.append(" ").append(type).append(": ").append(token);
 				throw new IllegalArgumentException(message.toString());
 			}
 			stack.push(result);
diff --git a/src/main/java/org/scijava/parsington/eval/StandardTreeEvaluator.java b/src/main/java/org/scijava/parsington/eval/StandardTreeEvaluator.java
index a29308d..6e3981e 100644
--- a/src/main/java/org/scijava/parsington/eval/StandardTreeEvaluator.java
+++ b/src/main/java/org/scijava/parsington/eval/StandardTreeEvaluator.java
@@ -49,7 +49,7 @@ default Object execute(final Operator op, final SyntaxTree tree) {
 		// Handle short-circuiting operators first.
 		if (op == Operators.LOGICAL_AND) {
 			final Object leftValue = value(evaluate(tree.child(0)));
-			if (leftValue instanceof Boolean && !((Boolean) leftValue).booleanValue()) {
+			if (leftValue instanceof Boolean && !(Boolean) leftValue) {
 				// Left side is false, so entire expression will be false.
 				return false;
 			}
@@ -58,7 +58,7 @@ default Object execute(final Operator op, final SyntaxTree tree) {
 		}
 		else if (op == Operators.LOGICAL_OR) {
 			final Object leftValue = value(evaluate(tree.child(0)));
-			if (leftValue instanceof Boolean && ((Boolean) leftValue).booleanValue()) {
+			if (leftValue instanceof Boolean && (Boolean) leftValue) {
 				// Left side is true, so entire expression will be true.
 				return true;
 			}