Add patterns to Rust AST

8 files changed, 123 insertions, 18 deletions

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttransient0/RustTransient0Generator.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttransient0/RustTransient0Generator.java
index 7122e54..ab1c7d3 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttransient0/RustTransient0Generator.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttransient0/RustTransient0Generator.java
@@ -523,7 +523,7 @@ public class RustTransient0Generator implements Generator {
                 Optional.empty()
             )),
             new RustExpressionStatement(new RustIteratorLoopExpression(
-                element,
+                new RustIdentifierPattern(element),
                 value,
                 new RustBlockExpression(
                     generateEncode(RustPath.of(element), elementType),
@@ -546,7 +546,7 @@ public class RustTransient0Generator implements Generator {
                 )),
                 new RustExpressionStatement(new RustIteratorLoopExpression(
                     // TODO: remove unnecessary variable
-                    RustIdentifier.of("element_index"),
+                    new RustIdentifierPattern(RustIdentifier.of("element_index")),
                     new RustRangeExpr(new RustIntegerLiteral(0, Optional.empty()), RustPath.of(length)),
                     new RustBlockExpression(
                         List.of(new RustExpressionStatement(
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 3aaa588..ef73933 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
@@ -531,7 +531,7 @@ public class RustWriter implements AutoCloseable {
         RustIteratorLoopExpression iteratorLoopExpression
     ) throws IOException {
         this.writer.write("for ");
-        this.writeIdentifier(iteratorLoopExpression.elementName());
+        this.writePattern(iteratorLoopExpression.pattern());
         this.writer.write(" in ");
         this.writeTopLevelExpression(iteratorLoopExpression.elements());
         this.writer.write(" ");
@@ -614,6 +614,22 @@ public class RustWriter implements AutoCloseable {
         this.writer.write("]");
     }
 
+    // == Patterns ==
+
+    private void writePattern(RustPattern pattern) throws IOException {
+        switch (pattern) {
+            case RustIdentifierPattern identifierPattern -> {
+                this.writeIdentifierPattern(identifierPattern);
+            }
+        }
+    }
+
+    private void writeIdentifierPattern(
+        RustIdentifierPattern identifierPattern
+    ) throws IOException {
+        this.writeIdentifier(identifierPattern.variableName());
+    }
+
     // == Types ==
 
     void writeType(RustType type) throws IOException {
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifierPattern.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifierPattern.java
new file mode 100644
index 0000000..ec06983
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifierPattern.java
@@ -0,0 +1,32 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern imports
+
+public record RustIdentifierPattern(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier variableName) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier variableName) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern(variableName);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder withVariableName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier variableName) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder(variableName);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder withVariableName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder variableName) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder(variableName.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern body
+}
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
index 0cd1ceb..da46e36 100644
--- 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
@@ -5,38 +5,38 @@ 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 record RustIteratorLoopExpression(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern pattern, 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());
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern.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 record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern pattern, 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);
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression(pattern, 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 withPattern(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern pattern) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(pattern, 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 withPattern(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern.Builder pattern) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(pattern.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);
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(pattern, 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);
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(pattern, 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);
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(pattern, 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());
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder(pattern, elements, body.build());
         }
 
         // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression.Builder body
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPattern.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPattern.java
new file mode 100644
index 0000000..47e7237
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPattern.java
@@ -0,0 +1,18 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern imports
+
+public sealed interface RustPattern permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern {
+    public interface Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern build();
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern 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 46180fb..5ffebf1 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
@@ -626,7 +626,7 @@ public class RustWriterTests {
     @Test
     public void iteratorExpression() throws IOException {
         var rust = RustIteratorLoopExpression.arbitrary()
-            .withElementName(RustIdentifier.of("x"))
+            .withPattern(RustIdentifierPattern.arbitrary().withVariableName(RustIdentifier.of("x")))
             .withElements(RustPath.of("xs"))
             .withBody(RustBlockExpression.arbitrary()
                 .withFinalOperand(RustCallExpression.arbitrary()
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifierPatternMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifierPatternMatcher.java
new file mode 100644
index 0000000..4743c56
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifierPatternMatcher.java
@@ -0,0 +1,39 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher imports
+
+public class RustIdentifierPatternMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher isRustIdentifierPattern() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern>> submatchers;
+
+    private RustIdentifierPatternMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern>> 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.RustIdentifierPattern.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher withVariableName(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier> variableName) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("variableName", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern::variableName, variableName));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPatternMatcher body
+}
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
index 6bd153a..2f9d517 100644
--- 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
@@ -28,9 +28,9 @@ public class RustIteratorLoopExpressionMatcher implements org.zwobble.precisely.
         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) {
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher withPattern(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern> pattern) {
         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));
+        submatchers.add(org.zwobble.precisely.Matchers.has("pattern", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpression::pattern, pattern));
         return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIteratorLoopExpressionMatcher(submatchers);
     }