Add parser for minimal functions

3 files changed, 93 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/UntypedFunctionDefinitionNodeMatcher.java b/src/test/java/org/shedlang/compiler/ast/UntypedFunctionDefinitionNodeMatcher.java
new file mode 100644
index 00000000..775cf5f5
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/ast/UntypedFunctionDefinitionNodeMatcher.java
@@ -0,0 +1,50 @@
+package org.shedlang.compiler.ast;
+
+import org.pcollections.PVector;
+import org.shedlang.compiler.testing.MatcherBuilder;
+import org.zwobble.precisely.Matcher;
+
+import java.util.Optional;
+
+import static org.zwobble.precisely.Matchers.equalTo;
+import static org.zwobble.precisely.Matchers.has;
+
+public class UntypedFunctionDefinitionNodeMatcher extends MatcherBuilder<UntypedNamespaceStatementNode, UntypedFunctionDefinitionNode, UntypedFunctionDefinitionNodeMatcher> {
+    public UntypedFunctionDefinitionNodeMatcher() {
+        super();
+    }
+
+    public UntypedFunctionDefinitionNodeMatcher(PVector<Matcher<? super UntypedFunctionDefinitionNode>> submatchers) {
+        super(submatchers);
+    }
+
+    @Override
+    protected Class<UntypedFunctionDefinitionNode> expectedType() {
+        return UntypedFunctionDefinitionNode.class;
+    }
+
+    @Override
+    protected UntypedFunctionDefinitionNodeMatcher create(PVector<Matcher<? super UntypedFunctionDefinitionNode>> submatchers) {
+        return new UntypedFunctionDefinitionNodeMatcher();
+    }
+
+    public UntypedFunctionDefinitionNodeMatcher withBody(Matcher<Iterable<UntypedFunctionStatementNode>> body) {
+        return with(has("body", x -> x.body(), body));
+    }
+
+    public UntypedFunctionDefinitionNodeMatcher withEffect(Matcher<Optional<UntypedTypeLevelExpressionNode>> effect) {
+        return with(has("effect", x -> x.effect(), effect));
+    }
+
+    public UntypedFunctionDefinitionNodeMatcher withName(String name) {
+        return with(has("name", x -> x.name(), equalTo(name)));
+    }
+
+    public UntypedFunctionDefinitionNodeMatcher withParams(Matcher<UntypedParamsNode> params) {
+        return with(has("params", x -> x.params(), params));
+    }
+
+    public UntypedFunctionDefinitionNodeMatcher withReturnType(Matcher<UntypedTypeLevelExpressionNode> returnType) {
+        return with(has("returnType", x -> x.returnType(), returnType));
+    }
+}
diff --git a/src/test/java/org/shedlang/compiler/ast/UntypedNodeMatchers.java b/src/test/java/org/shedlang/compiler/ast/UntypedNodeMatchers.java
index a6f0bf82..ca538a97 100644
--- a/src/test/java/org/shedlang/compiler/ast/UntypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/UntypedNodeMatchers.java
@@ -25,6 +25,10 @@ public class UntypedNodeMatchers {
         );
     }
 
+    public static UntypedFunctionDefinitionNodeMatcher isUntypedFunctionDefinitionNode() {
+        return new UntypedFunctionDefinitionNodeMatcher();
+    }
+
     public static Matcher<UntypedNamedArgNode> isUntypedNamedArgNode(
         String name,
         Matcher<UntypedExpressionNode> expression
@@ -35,6 +39,16 @@ public class UntypedNodeMatchers {
         );
     }
 
+    public static Matcher<UntypedParamsNode> isUntypedParamsNode(
+        Matcher<Iterable<UntypedParamNode>> positional,
+        Matcher<Iterable<UntypedParamNode>> named
+    ) {
+        return allOf(
+            has("positional", x -> x.positional(), positional),
+            has("named", x -> x.named(), named)
+        );
+    }
+
     public static Matcher<UntypedExpressionNode> isUntypedReferenceNode(String name) {
         return instanceOf(
             UntypedReferenceNode.class,
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java b/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java
new file mode 100644
index 00000000..34c50065
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java
@@ -0,0 +1,29 @@
+package org.shedlang.compiler.parser;
+
+import org.junit.jupiter.api.Test;
+
+import static org.shedlang.compiler.ast.UntypedNodeMatchers.*;
+import static org.shedlang.compiler.parser.ParserTesting.parseString;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.*;
+
+public class ParserFunctionDefinitionTests {
+    @Test
+    public void canParseMinimalFunction() {
+        var source = """
+            fun f() -> Unit {
+            }""";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedFunctionDefinitionNode()
+                .withName("f")
+                .withParams(isUntypedParamsNode(isSequence(), isSequence()))
+                .withEffect(isOptionalEmpty())
+                .withReturnType(isUntypedTypeLevelReferenceNode("Unit"))
+                .withBody(isSequence())
+        );
+    }
+}