Add iterator loop expressions to Rust AST

6 files changed, 146 insertions, 1 deletions

diff --git a/hobgoblin/src/output/lang/rust/ast.hob b/hobgoblin/src/output/lang/rust/ast.hob
index a5641d1..d362291 100644
--- a/hobgoblin/src/output/lang/rust/ast.hob
+++ b/hobgoblin/src/output/lang/rust/ast.hob
@@ -130,6 +130,7 @@ sum RustExpression {
     variant RustFieldExpression;
     variant RustIfExpression;
     variant RustIntegerLiteral;
+    variant RustIteratorLoopExpression;
     variant RustPath;
     variant RustPrefixExpression;
     variant RustStructExpression;
@@ -185,6 +186,12 @@ struct RustIntegerLiteral {
     field type: Option[RustIdentifier];
 }
 
+struct RustIteratorLoopExpression {
+    field elementName: RustIdentifier;
+    field elements: RustExpression;
+    field body: RustBlockExpression;
+}
+
 struct RustPrefixExpression {
     field operator: RustPrefixOperator;
     field operand: RustExpression;
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
index d4228b0..d916311 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
@@ -347,6 +347,10 @@ public class RustWriter implements AutoCloseable {
                 this.writeIntegerLiteral(integerLiteral);
             }
 
+            case RustIteratorLoopExpression iteratorLoopExpression -> {
+                this.writeIteratorLoopExpression(iteratorLoopExpression);
+            }
+
             case RustPath path -> {
                 this.writePath(path);
             }
@@ -405,6 +409,7 @@ public class RustWriter implements AutoCloseable {
             case RustFieldExpression _ -> RustPrecedence.FIELD_EXPRESSIONS;
             case RustIfExpression _ -> RustPrecedence.PRIMARY;
             case RustIntegerLiteral _ -> RustPrecedence.PRIMARY;
+            case RustIteratorLoopExpression _ -> RustPrecedence.PRIMARY;
             case RustPath _ -> RustPrecedence.PATHS;
             case RustPrefixExpression _ -> RustPrecedence.PREFIX;
             case RustStructExpression _ -> RustPrecedence.PRIMARY;
@@ -517,6 +522,17 @@ public class RustWriter implements AutoCloseable {
         }
     }
 
+    private void writeIteratorLoopExpression(
+        RustIteratorLoopExpression iteratorLoopExpression
+    ) throws IOException {
+        this.writer.write("for ");
+        this.writeIdentifier(iteratorLoopExpression.elementName());
+        this.writer.write(" in ");
+        this.writeTopLevelExpression(iteratorLoopExpression.elements());
+        this.writer.write(" ");
+        this.writeBlockExpression(iteratorLoopExpression.body());
+    }
+
     private void writePrefixExpression(RustPrefixExpression prefixExpression) throws IOException {
         this.writer.write(switch (prefixExpression.operator()) {
             case BORROW -> "&";
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustExpression.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustExpression.java
index 95ca9f8..239f972 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustExpression.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustExpression.java
@@ -5,7 +5,7 @@ package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
 // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression imports
 // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression imports
 
-public sealed interface RustExpression permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustArrayRepeatExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBinaryExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBoolLiteral, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustCallExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFieldExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIfExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIntegerLiteral, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPrefixExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTryPropagationExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTupleExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustVecRepeatExpression {
+public sealed interface RustExpression permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustArrayRepeatExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBinaryExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBoolLiteral, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustCallExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFieldExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIfExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIntegerLiteral, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPrefixExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTryPropagationExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTupleExpression, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustVecRepeatExpression {
     public interface Builder {
         public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression build();
 
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIteratorLoopExpression.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIteratorLoopExpression.java
new file mode 100644
index 0000000..0cd1ceb
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIteratorLoopExpression.java
@@ -0,0 +1,48 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression imports
+
+public record RustIteratorLoopExpression(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier elementName, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression elements, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression body) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.arbitrary().build(), org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression.arbitrary().build(), org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier elementName, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression elements, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression body) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression(elementName, elements, body);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder withElementName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier elementName) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(elementName, elements, body);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder withElementName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder elementName) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(elementName.build(), elements, body);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder withElements(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression elements) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(elementName, elements, body);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder withElements(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression.Builder elements) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(elementName, elements.build(), body);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder withBody(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression body) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(elementName, elements, body);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder withBody(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression.Builder body) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(elementName, elements, body.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression body
+}
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
index bf93c1d..e947db9 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
@@ -621,6 +621,29 @@ public class RustWriterTests {
         assertThat(string, equalTo("123i32"));
     }
 
+    // === Iterator expressions ===
+
+    @Test
+    public void iteratorExpression() throws IOException {
+        var rust = RustIteratorLoopExpression.arbitrary()
+            .withElementName(RustIdentifier.of("x"))
+            .withElements(RustPath.of("xs"))
+            .withBody(RustBlockExpression.arbitrary()
+                .withFinalOperand(RustCallExpression.arbitrary()
+                    .withFunction(RustPath.of("print"))
+                    .addArg(RustPath.of("x"))
+                )
+            )
+            .build();
+
+        var string = write(writer -> writer.writeTopLevelExpression(rust));
+
+        assertThat(string, equalTo("""
+            for x in xs {
+                print(x)
+            }"""));
+    }
+
     // === Prefix expressions ===
 
     @Test
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIteratorLoopExpressionMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIteratorLoopExpressionMatcher.java
new file mode 100644
index 0000000..6bd153a
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIteratorLoopExpressionMatcher.java
@@ -0,0 +1,51 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher imports
+
+public class RustIteratorLoopExpressionMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher isRustIteratorLoopExpression() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression>> submatchers;
+
+    private RustIteratorLoopExpressionMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression>> submatchers) {
+        this.submatchers = submatchers;
+    }
+
+    public org.zwobble.precisely.MatchResult match(java.lang.Object actual) {
+        return this.toMatcher().match(actual);
+    }
+
+    public org.zwobble.precisely.TextTree describe() {
+        return this.toMatcher().describe();
+    }
+
+    private org.zwobble.precisely.Matcher<java.lang.Object> toMatcher() {
+        return org.zwobble.precisely.Matchers.instanceOf(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher withElementName(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier> elementName) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("elementName", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression::elementName, elementName));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher(submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher withElements(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression> elements) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("elements", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression::elements, elements));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher(submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher withBody(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustBlockExpression> body) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("body", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression::body, body));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher body
+}