Add index expressions to Rust AST

6 files changed, 118 insertions, 1 deletions

diff --git a/hobgoblin/src/output/lang/rust/ast.hob b/hobgoblin/src/output/lang/rust/ast.hob
index 2a2bc26..2a4aa41 100644
--- a/hobgoblin/src/output/lang/rust/ast.hob
+++ b/hobgoblin/src/output/lang/rust/ast.hob
@@ -130,6 +130,7 @@ sum RustExpression {
     variant RustClosureExpression;
     variant RustFieldExpression;
     variant RustIfExpression;
+    variant RustIndexExpression;
     variant RustIntegerLiteral;
     variant RustIteratorLoopExpression;
     variant RustMatchExpression;
@@ -196,6 +197,11 @@ struct RustIfExpression {
     field ifFalse: RustBlockExpression;
 }
 
+struct RustIndexExpression {
+    field indexed: RustExpression;
+    field index: RustExpression;
+}
+
 struct RustIntegerLiteral {
     field value: Int64;
     field type: Option[RustIdentifier];
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 af6c1a7..fe12f9f 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.writeIfExpression(ifExpression);
             }
 
+            case RustIndexExpression indexExpression -> {
+                this.writeIndexExpression(indexExpression);
+            }
+
             case RustIntegerLiteral integerLiteral -> {
                 this.writeIntegerLiteral(integerLiteral);
             }
@@ -425,6 +429,7 @@ public class RustWriter implements AutoCloseable {
             case RustClosureExpression _ -> RustPrecedence.PRIMARY;
             case RustFieldExpression _ -> RustPrecedence.FIELD_EXPRESSIONS;
             case RustIfExpression _ -> RustPrecedence.PRIMARY;
+            case RustIndexExpression _ -> RustPrecedence.FUNCTION_CALLS;
             case RustIntegerLiteral _ -> RustPrecedence.PRIMARY;
             case RustIteratorLoopExpression _ -> RustPrecedence.PRIMARY;
             case RustMatchExpression _ -> RustPrecedence.PRIMARY;
@@ -569,6 +574,13 @@ public class RustWriter implements AutoCloseable {
         this.writeBlockExpression(ifExpression.ifFalse());
     }
 
+    private void writeIndexExpression(RustIndexExpression indexExpression) throws IOException {
+        this.writeSubExpression(indexExpression.indexed(), precedence(indexExpression), true);
+        this.writer.write("[");
+        this.writeTopLevelExpression(indexExpression.index());
+        this.writer.write("]");
+    }
+
     private void writeIntegerLiteral(RustIntegerLiteral integerLiteral) throws IOException {
         this.writer.write(Long.toString(integerLiteral.value()));
         if (integerLiteral.type().isPresent()) {
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 9f15f5b..c418608 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.RustClosureExpression, 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.RustMatchExpression, 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.RustRangeExpr, 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.RustTypeCastExpression, 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.RustClosureExpression, 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.RustIndexExpression, 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.RustMatchExpression, 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.RustRangeExpr, 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.RustTypeCastExpression, 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/RustIndexExpression.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIndexExpression.java
new file mode 100644
index 0000000..a204997
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIndexExpression.java
@@ -0,0 +1,40 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression imports
+
+public record RustIndexExpression(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression indexed, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression index) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder(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.RustExpression indexed, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression index) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression(indexed, index);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder withIndexed(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression indexed) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder(indexed, index);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder withIndexed(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression.Builder indexed) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder(indexed.build(), index);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder withIndex(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression index) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder(indexed, index);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder withIndex(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression.Builder index) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder(indexed, index.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression 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 b5dd515..8946855 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
@@ -650,6 +650,20 @@ public class RustWriterTests {
             }"""));
     }
 
+    // === Index expressions ==
+
+    @Test
+    public void indexExpression() throws IOException {
+        var rust = RustIndexExpression.arbitrary()
+            .withIndexed(RustPath.of("x"))
+            .withIndex(RustPath.of("y"))
+            .build();
+
+        var string = write(writer -> writer.writeTopLevelExpression(rust));
+
+        assertThat(string, equalTo("x[y]"));
+    }
+
     // === Integer literals ===
 
     @Test
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIndexExpressionMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIndexExpressionMatcher.java
new file mode 100644
index 0000000..4261e0e
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIndexExpressionMatcher.java
@@ -0,0 +1,45 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher imports
+
+public class RustIndexExpressionMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher isRustIndexExpression() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression>> submatchers;
+
+    private RustIndexExpressionMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression>> 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.RustIndexExpression.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher withIndexed(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression> indexed) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("indexed", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression::indexed, indexed));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher(submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher withIndex(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression> index) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("index", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpression::index, index));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIndexExpressionMatcher body
+}