Parse while loops

7 files changed, 82 insertions, 2 deletions

diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionStatementNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionStatementNode.java
index 7ccd4cbd..5fadfcaf 100644
--- a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionStatementNode.java
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionStatementNode.java
@@ -2,6 +2,6 @@ package org.shedlang.compiler.ast.untyped;
 
 import java.util.List;
 
-public sealed interface UntypedFunctionStatementNode extends UntypedNode permits UntypedAssignNode, UntypedBlockReturnNode, UntypedExpressionStatementNode, UntypedFunctionReturnNode, UntypedValNode, UntypedVarNode {
+public sealed interface UntypedFunctionStatementNode extends UntypedNode permits UntypedAssignNode, UntypedBlockReturnNode, UntypedExpressionStatementNode, UntypedFunctionReturnNode, UntypedValNode, UntypedVarNode, UntypedWhileNode {
     UntypedFunctionStatementBehaviour behaviour();
 }
diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedWhileNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedWhileNode.java
new file mode 100644
index 00000000..29a5f0e8
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedWhileNode.java
@@ -0,0 +1,14 @@
+package org.shedlang.compiler.ast.untyped;
+
+import org.shedlang.compiler.sources.Source;
+
+public record UntypedWhileNode(
+    UntypedExpressionNode condition,
+    UntypedBlockNode body,
+    Source source
+) implements UntypedFunctionStatementNode {
+    @Override
+    public UntypedFunctionStatementBehaviour behaviour() {
+        return UntypedFunctionStatementBehaviour.CONTINUE;
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/parser/Parser.java b/src/main/java/org/shedlang/compiler/parser/Parser.java
index 9bf95612..a5a48756 100644
--- a/src/main/java/org/shedlang/compiler/parser/Parser.java
+++ b/src/main/java/org/shedlang/compiler/parser/Parser.java
@@ -315,6 +315,9 @@ public class Parser {
             case KEYWORD_VAR ->
                 parseVar(tokens);
 
+            case KEYWORD_WHILE ->
+                parseWhile(tokens);
+
             default ->
                 parseExpressionStatement(tokens);
         };
@@ -601,4 +604,22 @@ public class Parser {
 
         return new UntypedVarNode(target, expression, source);
     }
+
+    private static UntypedFunctionStatementNode parseWhile(
+        TokenIterator<TokenType> tokens
+    ) {
+        var start = tokens.position();
+
+        tokens.skip(TokenType.KEYWORD_WHILE);
+        tokens.skip(TokenType.SYMBOL_PAREN_OPEN);
+        var condition = parseTopLevelExpression(tokens);
+        tokens.skip(TokenType.SYMBOL_PAREN_CLOSE);
+
+        var body = parseBlock(tokens);
+
+        var end = tokens.position();
+        var source = start.to(end);
+
+        return new UntypedWhileNode(condition, body, source);
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java b/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java
index 2e7e236e..485aa8fa 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java
@@ -39,6 +39,9 @@ class DeclaredVariables {
 
             case UntypedVarNode var ->
                 forVar(var, variables);
+
+            case UntypedWhileNode while_ ->
+                variables;
         };
     }
 
diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index 5a3ee7a7..3eff92bf 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -558,6 +558,9 @@ public class TypeChecker {
 
             case UntypedVarNode var ->
                 typeCheckVar(var, context);
+
+            case UntypedWhileNode untypedWhileNode ->
+                throw new UnsupportedOperationException("TODO");
         };
     }
 
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 a05c8e55..a5d4e693 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
@@ -59,7 +59,6 @@ public class UntypedNodeMatchers {
             has("expression", x -> x.expression(), expression)
         );
     }
-
     public static Matcher<UntypedExpressionNode> isUntypedBoolLiteralNode(boolean value) {
         return instanceOf(
             UntypedBoolLiteralNode.class,
@@ -226,4 +225,15 @@ public class UntypedNodeMatchers {
             has("expression", x -> x.expression(), expression)
         );
     }
+
+    public static Matcher<UntypedFunctionStatementNode> isUntypedWhileNode(
+        Matcher<UntypedExpressionNode> condition,
+        Matcher<UntypedBlockNode> body
+    ) {
+        return instanceOf(
+            UntypedWhileNode.class,
+            has("condition", x -> x.condition(), condition),
+            has("body", x -> x.body(), body)
+        );
+    }
 }
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserWhileTests.java b/src/test/java/org/shedlang/compiler/parser/ParserWhileTests.java
new file mode 100644
index 00000000..8382f2fa
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/parser/ParserWhileTests.java
@@ -0,0 +1,29 @@
+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;
+import static org.zwobble.precisely.Matchers.isSequence;
+
+public class ParserWhileTests {
+    @Test
+    public void canParseWhile() {
+        var source = """
+            while (true) {
+                f();
+            }""";
+
+        var node = parseString(source, Parser::parseFunctionStatement);
+
+        assertThat(node, isUntypedWhileNode(
+            isUntypedBoolLiteralNode(true),
+            isUntypedBlockNode(isSequence(
+                isUntypedExpressionStatementNode(
+                    isUntypedCallNode().withReceiver(isUntypedReferenceNode("f"))
+                )
+            ))
+        ));
+    }
+}