Using typeDSL in metaschema.

Author: Peter Amstutz

schema_salad/metaschema/metaschema.yml

@@ -84,7 +84,7 @@ $graph:
     URI resolution and JSON-LD context generation.
   fields:
     - name: _id
-      type: ["null", string]
+      type: string?
       jsonldPredicate:
         _id: sld:_id
         _type: "@id"
@@ -93,7 +93,7 @@ $graph:
         The predicate URI that this field corresponds to.
         Corresponds to JSON-LD `@id` directive.
     - name: _type
-      type: ["null", string]
+      type: string?
       doc: |
         The context type hint, corresponds to JSON-LD `@type` directive.
 
@@ -106,32 +106,32 @@ $graph:
           resolved using the vocabulary resolution rules.
 
     - name: _container
-      type: ["null", string]
+      type: string?
       doc: |
         Structure hint, corresponds to JSON-LD `@container` directive.
     - name: identity
-      type: ["null", boolean]
+      type: boolean?
       doc: |
         If true and `_type` is `@id` this indicates that the parent field must
         be resolved according to identity resolution rules instead of link
         resolution rules.  In addition, the field value is considered an
         assertion that the linked value exists; absence of an object in the loaded document
         with the URI is not an error.
     - name: noLinkCheck
-      type: ["null", boolean]
+      type: boolean?
       doc: |
         If true, this indicates that link validation traversal must stop at
         this field.  This field (it is is a URI) or any fields under it (if it
         is an object or array) are not subject to link checking.
     - name: mapSubject
-      type: ["null", string]
+      type: string?
       doc: |
         If the value of the field is a JSON object, it must be transformed
         into an array of JSON objects, where each key-value pair from the
         source JSON object is a list item, the list items must be JSON objects,
         and the key is assigned to the field specified by `mapSubject`.
     - name: mapPredicate
-      type: ["null", string]
+      type: string?
       doc: |
         Only applies if `mapSubject` is also provided.  If the value of the
         field is a JSON object, it is transformed as described in `mapSubject`,
@@ -140,9 +140,7 @@ $graph:
         field specified by `mapSubject` and the value assigned to the field
         specified by `mapPredicate`.
     - name: refScope
-      type:
-        - "null"
-        - int
+      type: int?
       doc: |
         If the field contains a relative reference, it must be resolved by
         searching for valid document references in each successive parent scope
@@ -157,7 +155,7 @@ $graph:
         `#foo/foo` and the `#foo`.  The last scope searched must be the top
         level scope before determining if the identifier cannot be resolved.
     - name: typeDSL
-      type: ["null", boolean]
+      type: boolean?
       doc: |
         Field must be expanded based on the the Schema Salad type DSL.
 
@@ -204,7 +202,7 @@ $graph:
       jsonldPredicate: "sld:doc"
 
     - name: docParent
-      type: ["null", string]
+      type: string?
       doc: |
         Hint to indicate that during documentation generation, documentation
         for this type should appear in a subsection under `docParent`.
@@ -226,7 +224,7 @@ $graph:
         _type: "@id"
 
     - name: docAfter
-      type: ["null", string]
+      type: string?
       doc: |
         Hint to indicate that during documentation generation, documentation
         for this type should appear after the `docAfter` section at the same
@@ -253,7 +251,7 @@ $graph:
       jsonldPredicate: "sld:jsonldPredicate"
 
     - name: documentRoot
-      type: ["null", boolean]
+      type: boolean?
       doc: |
         If true, indicates that the type is a valid at the document root.  At
         least one type in a schema must be tagged with `documentRoot: true`.
@@ -270,7 +268,7 @@ $graph:
         The name of the field
 
     - name: doc
-      type: ["null", string]
+      type: string?
       doc: |
         A documentation string for this field
       jsonldPredicate: "sld:doc"
@@ -344,7 +342,7 @@ $graph:
     specializeTo: "#SaladRecordField"
   fields:
     - name: abstract
-      type: ["null", boolean]
+      type: boolean?
       doc: |
         If true, this record is abstract and may be used as a base for other
         records, but is not valid on its own.

schema_salad/ref_resolver.py

@@ -364,6 +364,7 @@ def _type_dsl(self, t):
                  "items": r}
         if m.group(3):
             r = ["null", r]
+        print t, "DSL to", r
         return r
 
     def _resolve_type_dsl(self, document, loader):