implements PLN-0079

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsEditorialSupportService.java

@@ -741,9 +741,13 @@ public final class PbsEditorialSupportService {
             }
             final ArrayList<PbsEditorialSignature> signatures = new ArrayList<>(callables.size());
             for (final var callable : callables) {
-                final ArrayList<String> parameterLabels = new ArrayList<>(callable.inputTypes().size());
+                final ArrayList<String> parameterLabels = new ArrayList<>(callable.parameters().size());
-                for (int index = 0; index < callable.inputTypes().size(); index += 1) {
+                for (final var parameter : callable.parameters()) {
-                    parameterLabels.add("arg" + index + ": " + formatType(callable.inputTypes().get(index)));
+                    if (parameter.name() == null || parameter.name().isBlank()) {
+                        parameterLabels.add(formatType(parameter.type()));
+                    } else {
+                        parameterLabels.add(parameter.name() + ": " + formatType(parameter.type()));
+                    }
                 }
                 final String label = callable.name() + "(" + String.join(", ", parameterLabels) + ") -> " + formatType(callable.outputType());
                 signatures.add(new PbsEditorialSignature(callable.name(), label, parameterLabels, formatType(callable.outputType())));

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowSemanticSupport.java

@@ -143,11 +143,19 @@ final class PbsFlowSemanticSupport {
     
     record CallableSymbol(
             String name,
+            List<CallableParameter> parameters,
             List<TypeView> inputTypes,
             TypeView outputType,
             Span span) {
     }
 
+    record CallableParameter(
+            String name,
+            int order,
+            TypeView type,
+            Span span) {
+    }
+    
     record CallbackSignature(
             List<TypeView> inputTypes,
             TypeView outputType) {
@@ -469,10 +477,18 @@ final class PbsFlowSemanticSupport {
                 final PbsAst.TypeRef resultErrorType,
                 final Span span) {
             final var input = new ArrayList<TypeView>(parameters.size());
-            for (final var parameter : parameters) {
+            final var semanticParameters = new ArrayList<CallableParameter>(parameters.size());
-                input.add(typeFrom(parameter.typeRef()));
+            for (int index = 0; index < parameters.size(); index += 1) {
+                final var parameter = parameters.get(index);
+                final var type = typeFrom(parameter.typeRef());
+                input.add(type);
+                semanticParameters.add(new CallableParameter(
+                        parameter.name(),
+                        index,
+                        type,
+                        parameter.span()));
             }
-            return new CallableSymbol(name, input, callableReturn(returnKind, returnType, resultErrorType), span);
+            return new CallableSymbol(name, semanticParameters, input, callableReturn(returnKind, returnType, resultErrorType), span);
         }
     
         private TypeView callableReturn(

prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/pbs/semantics/PbsEditorialSupportServiceTest.java

@@ -155,7 +155,7 @@ final class PbsEditorialSupportServiceTest {
                 ReadOnlyList.empty(),
                 source.lastIndexOf("2);"));
         assertTrue(methodHelp.isPresent());
-        assertEquals("blend(arg0: int, arg1: int) -> int", methodHelp.orElseThrow().signatures().getFirst().label());
+        assertEquals("blend(dx: int, dy: int) -> int", methodHelp.orElseThrow().signatures().getFirst().label());
         assertEquals(1, methodHelp.orElseThrow().activeParameter());
 
         final var constructorHelp = service.signatureHelp(
@@ -171,6 +171,57 @@ final class PbsEditorialSupportServiceTest {
         assertEquals("Vec()", constructorHover.signatures().getFirst().label());
     }
 
+    @Test
+    void shouldPreserveSemanticParameterNamesForHostAndBuiltinCallables() {
+        final var source = """
+                import { Gfx, Sprite } from @sdk:gfx;
+
+                fn main(sprite: Sprite) -> void {
+                  Gfx.draw_pixel(1, 2, 3);
+                  sprite.blit(4, 5);
+                }
+                """;
+        final var ast = parseOrdinary(source);
+        final var supplementalTopDecls = supplementalTopDecls("""
+                declare host Gfx {
+                  fn draw_pixel(x: int, y: int, color: int) -> void;
+                }
+
+                declare builtin type Sprite(
+                  pub id: int
+                ) {
+                  fn blit(x: int, y: int) -> void;
+                }
+                """);
+
+        final var hostHelp = service.signatureHelp(
+                source,
+                ast,
+                supplementalTopDecls,
+                source.indexOf("2, 3"));
+        assertTrue(hostHelp.isPresent());
+        assertEquals("draw_pixel(x: int, y: int, color: int) -> void", hostHelp.orElseThrow().signatures().getFirst().label());
+        assertFalse(hostHelp.orElseThrow().signatures().getFirst().label().contains("arg"));
+
+        final var builtinHelp = service.signatureHelp(
+                source,
+                ast,
+                supplementalTopDecls,
+                source.indexOf("5);"));
+        assertTrue(builtinHelp.isPresent());
+        assertEquals("blit(x: int, y: int) -> void", builtinHelp.orElseThrow().signatures().getFirst().label());
+        assertFalse(builtinHelp.orElseThrow().signatures().getFirst().label().contains("arg"));
+
+        final var hostCompletion = service.completion(
+                source,
+                ast,
+                supplementalTopDecls,
+                source.indexOf("draw_pixel"));
+        assertTrue(hostCompletion.stream().anyMatch(candidate ->
+                candidate.label().equals("draw_pixel")
+                        && candidate.detail().equals("draw_pixel(x: int, y: int, color: int) -> void")));
+    }
+
     private PbsEditorialResolvedSymbol requireHover(
             final String source,
             final PbsAst.File ast,