Parse subtraction

2 files changed, 41 insertions, 5 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
index e7c8d01c..ff249a02 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
@@ -14,18 +14,26 @@ public class UntypedNodeMatchers {
         Matcher<UntypedExpressionNode> left,
         Matcher<UntypedExpressionNode> right
     ) {
+        return isUntypedBinaryOperationNode(UntypedBinaryOperator.ADD, left, right);
+    }
+
+    public static UntypedArgsNodeMatcher isUntypedArgsNode() {
+        return UntypedArgsNodeMatcher.empty();
+    }
+
+    public static Matcher<UntypedExpressionNode> isUntypedBinaryOperationNode(
+        UntypedBinaryOperator operator,
+        Matcher<UntypedExpressionNode> left,
+        Matcher<UntypedExpressionNode> right
+    ) {
         return instanceOf(
             UntypedBinaryOperationNode.class,
-            has("operator", x -> x.operator(), equalTo(UntypedBinaryOperator.ADD)),
+            has("operator", x -> x.operator(), equalTo(operator)),
             has("left", x -> x.left(), left),
             has("right", x -> x.right(), right)
         );
     }
 
-    public static UntypedArgsNodeMatcher isUntypedArgsNode() {
-        return UntypedArgsNodeMatcher.empty();
-    }
-
     public static UntypedCallNodeMatcher isUntypedCallNode() {
         return UntypedCallNodeMatcher.empty();
     }
@@ -107,6 +115,13 @@ public class UntypedNodeMatchers {
         );
     }
 
+    public static Matcher<UntypedExpressionNode> isUntypedSubNode(
+        Matcher<UntypedExpressionNode> left,
+        Matcher<UntypedExpressionNode> right
+    ) {
+        return isUntypedBinaryOperationNode(UntypedBinaryOperator.SUB, left, right);
+    }
+
     public static Matcher<UntypedTargetNode> isUntypedTargetVariableNode(String name) {
         return instanceOf(
             UntypedTargetNode.Variable.class,
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserSubTests.java b/src/test/java/org/shedlang/compiler/parser/ParserSubTests.java
new file mode 100644
index 00000000..ff331be1
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/parser/ParserSubTests.java
@@ -0,0 +1,21 @@
+package org.shedlang.compiler.parser;
+
+import org.junit.jupiter.api.Test;
+
+import static org.shedlang.compiler.ast.untyped.UntypedNodeMatchers.*;
+import static org.shedlang.compiler.parser.ParserTesting.parseString;
+import static org.zwobble.precisely.AssertThat.assertThat;
+
+public class ParserSubTests {
+    @Test
+    public void canParseSubtractionOfTwoPrimaryExpressions() {
+        var source = "1 - 2";
+
+        var node = parseString(source, Parser::parseTopLevelExpression);
+
+        assertThat(node, isUntypedSubNode(
+            isUntypedIntLiteralNode(1),
+            isUntypedIntLiteralNode(2)
+        ));
+    }
+}