typecheck: diagnose missing field values

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+### Diagnose missing values after `AS ... TO` field annotations
+
+- `claro typecheck` now explains how to repair an explicitly typed object-field assignment that ends after `TO`, such as `SET player.score AS NUMBER TO`.
+- Added focused negative coverage to the complete typecheck validation matrix.
+
 ### Diagnose extra words after short typed field assignments
 
 - `claro typecheck` now rejects trailing words after the value in short explicit object-field assignments such as `SET player.score NUMBER 10 extra`.

docs/ADVANCED_STATIC_TYPING.md

@@ -832,6 +832,16 @@ with a repair hint instead of being silently ignored:
 SET player.score AS NUMBER TO 10 extra
 ```
 
+The separated form also needs a value after `TO`:
+
+```claro
+SET player.score AS NUMBER TO
+```
+
+```text
+SET player.score needs a value after type NUMBER and TO. Add one expression.
+```
+
 ```text
 SET player.score has extra text after value 10. Keep only the field name, type, TO, and one expression.
 ```

docs/CURRENT_STATUS.md

@@ -83,7 +83,7 @@ Ready now:
 - object creation now rejects repeated object names with a direct repair hint, so two `NEW Player player` statements cannot silently replace one another during type checking; when a script declares at least one class, a misspelled `NEW` class name gets a direct declaration hint without changing the older permissive no-class form; a missing class name or object name gets a direct example repair; extra words after the object name get a direct repair hint instead of being silently ignored
 - a narrow object-field assignment/check-type check for simple `NEW Class object` plus direct `SET object.field value` and `CHECK TYPE object.field IS TYPE` cases when the class declares `HAS field TYPE`; validation now covers correct NUMBER, TEXT, and YESNO direct assignments, dedicated positive and explicitly typed NUMBER/TEXT field assignments, explicitly typed method-body assignments to undeclared fields with a `HAS field TYPE` repair hint in modern and compatibility method syntax, dedicated positive NUMBER/TEXT/YESNO `CHECK TYPE` metadata fixtures, simple and chained object aliases for both field assignments and `CHECK TYPE` metadata (including a chained TEXT-field check), aliased object-method calls including chained aliases in modern `DO` and compatibility `CALL ... WITH` forms (with a dedicated positive modern `DO` chained-alias fixture), field-to-field, compound arithmetic field expressions, and arithmetic/text expression result types, negative NUMBER/TEXT/YESNO field `CHECK TYPE` metadata mismatches, NUMBER/TEXT/YESNO-expectation unknown-field `CHECK TYPE` diagnostics, missing-object field assignment and `CHECK TYPE` diagnostics, NUMBER/TEXT/YESNO wrong-type diagnostics, field collection when a `HAS` field appears after a simple method, NUMBER/TEXT/YESNO-valued unknown-field diagnostics for direct assignments to undeclared fields including explicitly typed assignments, numeric and text results from simple arithmetic/text expressions in object-field assignments, plus method-body field assignment and `CHECK TYPE` diagnostics for NUMBER, TEXT, and YESNO fields in modern and compatibility syntax, including compatibility YESNO `CHECK TYPE` metadata coverage, direct method assignments to undeclared fields now produce a beginner-facing missing-field diagnostic when the assigned expression has a known type, and a plain beginner-facing unknown-field diagnostic when the assigned expression is not inferable yet in both modern and compatibility method syntax; method-body `CHECK TYPE` now reports an unknown field with a repair hint in both method syntaxes, including compatibility `TAKES` / `LEARNED` methods; explicitly typed assignments to declared method fields now validate the class-declared field type instead of trusting only the inline type annotation, so a wrong value such as `SET score TEXT \"oops\"` reports the method and field in the diagnostic.
 - inline method-field annotations are checked against the class `HAS` declaration in modern and compatibility methods; conflicting known types and unknown annotation names produce field-specific repair guidance, with positive and negative focused fixtures for both syntaxes.
-- direct object-field `AS ... TO` assignments reject extra words after the value with a repair hint, so `SET player.score AS NUMBER TO 10 extra` cannot silently ignore the trailing text; short explicitly typed assignments such as `SET player.score NUMBER 10 extra` receive the same repair-oriented check
+- direct object-field `AS ... TO` assignments reject extra words after the value with a repair hint, so `SET player.score AS NUMBER TO 10 extra` cannot silently ignore the trailing text; they also explain when the value is missing after `TO`; short explicitly typed assignments such as `SET player.score NUMBER 10 extra` receive the same repair-oriented check
 - Direct object-field validation also has positive coverage for explicit `NUMBER`, `TEXT`, and `YESNO` annotations, such as `SET player.ready YESNO YES`, plus the compatibility-shaped `AS ... TO` form such as `SET player.score AS NUMBER TO 10`, while the shorter unannotated form remains supported; method-body field assignments have matching positive coverage for both modern and compatibility `TEACH` forms using `SET score AS NUMBER TO 10`, and those two `AS ... TO` method fixtures are now included in `claro validate`; conflicting annotations such as `SET player.score TEXT "oops"` explain the class-declared type and how to repair it, and unknown annotations such as `SET player.score AS BANANA TO 10` or `SET player.score BANANA 10` identify the invalid type and suggest the declared field type.
 
 Still needed:

docs/ROADMAP.md

@@ -54,6 +54,7 @@ Keep declared return types honest: `claro typecheck` now reports friendly diagno
 8d.3. Keep release validation aligned with method annotation coverage: the modern and compatibility `AS ... TO` method fixtures now run through `claro validate`, not only the focused Python diagnostic validator.
 8d.4. Keep separated direct field assignments unambiguous: `SET player.score AS NUMBER TO 10 extra` now reports the trailing text and explains the one-expression form instead of accepting a partially parsed value.
 8d.5. Keep short direct field assignments unambiguous: `SET player.score NUMBER 10 extra` now rejects trailing words with a repair hint, matching the separated `AS ... TO` form.
+8d.6. Keep separated direct field assignments complete: `SET player.score AS NUMBER TO` now explains that one value expression is required after `TO`.
 8e. Keep inline method-field annotation coverage aligned across syntax generations: compatibility `TAKES` / `LEARNED` methods now have matching positive and negative fixtures, so older lessons retain the same class-declared-type guidance.
 8f. Keep inline method-field annotations learner-facing: an unknown annotation such as `BANANA` now names the field and method and suggests the `HAS` type instead of silently treating the annotation as an expression.
 8g. Keep unknown inline method-field annotation diagnostics aligned across syntax generations: compatibility `TAKES` / `LEARNED` methods now have matching focused coverage for misspelled annotations.

tests/typecheck_object_field_typed_as_to_missing_value_bad.claro

@@ -0,0 +1,6 @@
+CLASS Player
+    HAS score NUMBER
+END
+
+NEW Player player
+SET player.score AS NUMBER TO

tools/validate_typecheck_diagnostics.py

@@ -263,6 +263,9 @@ EXPECTED = {
     "tests/typecheck_object_field_typed_as_to_extra_tokens_bad.claro": [
         "tests/typecheck_object_field_typed_as_to_extra_tokens_bad.claro:6: SET player.score has extra text after value 10. Keep only the field name, type, TO, and one expression.",
     ],
+    "tests/typecheck_object_field_typed_as_to_missing_value_bad.claro": [
+        "tests/typecheck_object_field_typed_as_to_missing_value_bad.claro:6: SET player.score needs a value after type NUMBER and TO. Add one expression.",
+    ],
     "tests/typecheck_object_field_short_extra_tokens_bad.claro": [
         "tests/typecheck_object_field_short_extra_tokens_bad.claro:6: SET player.score has extra text after value 10. Keep only the field name, type, and one expression.",
     ],