Add wildcard patterns to Rust AST

6 files changed, 98 insertions, 2 deletions

diff --git a/hobgoblin/src/output/lang/rust/ast.hob b/hobgoblin/src/output/lang/rust/ast.hob
index cb4a5cf..68cd64e 100644
--- a/hobgoblin/src/output/lang/rust/ast.hob
+++ b/hobgoblin/src/output/lang/rust/ast.hob
@@ -236,12 +236,15 @@ struct RustVecRepeatExpression {
 
 sum RustPattern {
     variant RustIdentifierPattern;
+    variant RustWildcardPattern;
 }
 
 struct RustIdentifierPattern {
     field variableName: RustIdentifier;
 }
 
+struct RustWildcardPattern {}
+
 // == Types ==
 
 sum RustType {
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 ef73933..e3991c8 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
@@ -616,11 +616,15 @@ public class RustWriter implements AutoCloseable {
 
     // == Patterns ==
 
-    private void writePattern(RustPattern pattern) throws IOException {
+    void writePattern(RustPattern pattern) throws IOException {
         switch (pattern) {
             case RustIdentifierPattern identifierPattern -> {
                 this.writeIdentifierPattern(identifierPattern);
             }
+
+            case RustWildcardPattern wildcardPattern -> {
+                this.writeWildcardPattern(wildcardPattern);
+            }
         }
     }
 
@@ -630,6 +634,12 @@ public class RustWriter implements AutoCloseable {
         this.writeIdentifier(identifierPattern.variableName());
     }
 
+    private void writeWildcardPattern(
+        RustWildcardPattern wildcardPattern
+    ) throws IOException {
+        this.writer.write("_");
+    }
+
     // == Types ==
 
     void writeType(RustType type) throws IOException {
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
index 47e7237..50ee8eb 100644
--- 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
@@ -5,7 +5,7 @@ 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 sealed interface RustPattern permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifierPattern, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern {
     public interface Builder {
         public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern build();
 
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustWildcardPattern.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustWildcardPattern.java
new file mode 100644
index 0000000..7bc3ce7
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustWildcardPattern.java
@@ -0,0 +1,24 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern imports
+
+public record RustWildcardPattern() implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern.Builder();
+    }
+
+    public record Builder() implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern();
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern 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 5ffebf1..d036f78 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
@@ -835,6 +835,32 @@ public class RustWriterTests {
         assertThat(string, equalTo("a + b + (c + d)"));
     }
 
+    // == Patterns ==
+
+    // === Identifier patterns ===
+
+    @Test
+    public void identifierPattern() throws IOException {
+        var rust = RustIdentifierPattern.arbitrary()
+            .withVariableName(RustIdentifier.of("x"))
+            .build();
+
+        var string = write(writer -> writer.writePattern(rust));
+
+        assertThat(string, equalTo("x"));
+    }
+
+    // === Wildcard patterns ===
+
+    @Test
+    public void wildcardPattern() throws IOException {
+        var rust = RustWildcardPattern.arbitrary().build();
+
+        var string = write(writer -> writer.writePattern(rust));
+
+        assertThat(string, equalTo("_"));
+    }
+
     // == Types ==
 
     @Test
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustWildcardPatternMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustWildcardPatternMatcher.java
new file mode 100644
index 0000000..26eee96
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustWildcardPatternMatcher.java
@@ -0,0 +1,33 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPatternMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPatternMatcher imports
+
+public class RustWildcardPatternMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPatternMatcher isRustWildcardPattern() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPatternMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern>> submatchers;
+
+    private RustWildcardPatternMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPattern>> 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.RustWildcardPattern.class, this.submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPatternMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustWildcardPatternMatcher body
+}