Contributed values are expressions (#754)

Author: mandel

src/pdl/pdl-schema.json

@@ -1407,9 +1407,19 @@
       "additionalProperties": false,
       "properties": {
         "value": {
-          "items": {},
-          "title": "Value",
-          "type": "array"
+          "anyOf": [
+            {
+              "items": {},
+              "type": "array"
+            },
+            {
+              "type": "string"
+            },
+            {
+              "$ref": "#/$defs/LocalizedExpression_TypeVar_"
+            }
+          ],
+          "title": "Value"
         }
       },
       "required": [

src/pdl/pdl_ast.py

@@ -175,7 +175,7 @@ class ContributeTarget(StrEnum):
 
 
 class ContributeValue(BaseModel):
-    value: list[Any]
+    value: ExpressionType[list[Any]]
     model_config = ConfigDict(extra="forbid")