From f497e7f884856ca91f3697886db559af070a92ba Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Wed, 5 Jul 2023 21:30:56 +0100
Subject: Parse function definition params

---
 .../compiler/ast/untyped/UntypedNodeMatchers.java  |  10 ++
 .../parser/ParserFunctionDefinitionTests.java      | 119 +++++++++++++++++++++
 2 files changed, 129 insertions(+)

(limited to 'src/test/java')

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 acddc159..ad6c8a49 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
@@ -52,6 +52,16 @@ public class UntypedNodeMatchers {
         );
     }
 
+    public static Matcher<UntypedParamNode> isUntypedParamNode(
+        String name,
+        Matcher<UntypedTypeLevelExpressionNode> type
+    ) {
+        return allOf(
+            has("name", x -> x.name(), equalTo(name)),
+            has("type", x -> x.type(), type)
+        );
+    }
+
     public static Matcher<UntypedParamsNode> isUntypedParamsNode(
         Matcher<Iterable<? extends UntypedParamNode>> positional,
         Matcher<Iterable<? extends UntypedParamNode>> named
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java b/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java
index f718bfca..607a06bf 100644
--- a/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java
+++ b/src/test/java/org/shedlang/compiler/parser/ParserFunctionDefinitionTests.java
@@ -2,6 +2,7 @@ package org.shedlang.compiler.parser;
 
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.shedlang.compiler.ast.untyped.UntypedNodeMatchers.*;
 import static org.shedlang.compiler.parser.ParserTesting.parseString;
 import static org.zwobble.precisely.AssertThat.assertThat;
@@ -27,6 +28,124 @@ public class ParserFunctionDefinitionTests {
         );
     }
 
+    @Test
+    public void canParseFunctionWithSinglePositionalParam() {
+        var source = """
+            fun f(a: Int) -> Unit {
+            }""";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedFunctionDefinitionNode()
+                .withParams(isUntypedParamsNode(
+                    isSequence(
+                        isUntypedParamNode("a", isUntypedTypeLevelReferenceNode("Int"))
+                    ),
+                    isSequence()
+                ))
+        );
+    }
+
+    @Test
+    public void canParseFunctionWithManyPositionalParams() {
+        var source = """
+            fun f(a: Int, b: String, c: Bool) -> Unit {
+            }""";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedFunctionDefinitionNode()
+                .withParams(isUntypedParamsNode(
+                    isSequence(
+                        isUntypedParamNode("a", isUntypedTypeLevelReferenceNode("Int")),
+                        isUntypedParamNode("b", isUntypedTypeLevelReferenceNode("String")),
+                        isUntypedParamNode("c", isUntypedTypeLevelReferenceNode("Bool"))
+                    ),
+                    isSequence()
+                ))
+        );
+    }
+
+    @Test
+    public void canParseFunctionWithSingleNamedParam() {
+        var source = """
+            fun f(.a: Int) -> Unit {
+            }""";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedFunctionDefinitionNode()
+                .withParams(isUntypedParamsNode(
+                    isSequence(),
+                    isSequence(
+                        isUntypedParamNode("a", isUntypedTypeLevelReferenceNode("Int"))
+                    )
+                ))
+        );
+    }
+
+    @Test
+    public void canParseFunctionWithManyNamedParams() {
+        var source = """
+            fun f(.a: Int, .b: String, .c: Bool) -> Unit {
+            }""";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedFunctionDefinitionNode()
+                .withParams(isUntypedParamsNode(
+                    isSequence(),
+                    isSequence(
+                        isUntypedParamNode("a", isUntypedTypeLevelReferenceNode("Int")),
+                        isUntypedParamNode("b", isUntypedTypeLevelReferenceNode("String")),
+                        isUntypedParamNode("c", isUntypedTypeLevelReferenceNode("Bool"))
+                    )
+                ))
+        );
+    }
+
+    @Test
+    public void canParseNamedParamAfterPositionalParam() {
+        var source = """
+            fun f(a: Int, .b: String) -> Unit {
+            }""";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedFunctionDefinitionNode()
+                .withParams(isUntypedParamsNode(
+                    isSequence(
+                        isUntypedParamNode("a", isUntypedTypeLevelReferenceNode("Int"))
+                    ),
+                    isSequence(
+                        isUntypedParamNode("b", isUntypedTypeLevelReferenceNode("String"))
+                    )
+                ))
+        );
+    }
+
+    @Test
+    public void cannotParsePositionalParamAfterNamedParam() {
+        var source = """
+            fun f(.a: Int, b: String) -> Unit {
+            }""";
+
+        assertThrows(
+            PositionalParamAfterNamedParamError.class,
+            () -> parseString(source, Parser::parseNamespaceStatement)
+        );
+    }
+
     @Test
     public void canParseFunctionWithEffect() {
         var source = """
-- 
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