From f2787ed9b40deabbbc9cbe2a6d38cafd1436fc6f Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Sat, 19 Aug 2023 10:42:44 +0100
Subject: Parse while loops

---
 .../ast/untyped/UntypedFunctionStatementNode.java   |  2 +-
 .../compiler/ast/untyped/UntypedWhileNode.java      | 14 ++++++++++++++
 .../java/org/shedlang/compiler/parser/Parser.java   | 21 +++++++++++++++++++++
 .../compiler/typechecker/DeclaredVariables.java     |  3 +++
 .../shedlang/compiler/typechecker/TypeChecker.java  |  3 +++
 5 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/org/shedlang/compiler/ast/untyped/UntypedWhileNode.java

(limited to 'src/main/java')

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");
         };
     }
 
-- 
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