Allow using similarity_measure at the set level. (#412)

We add the `similarity_measure` slot to the MappingSet class, as a
propagatable slot. It should be quite common that all `similarity_score`
for all mappings in a set are determined using the same measure, so it
makes sense to allow setting the measure once and for all at the set
level, without having to repeat that information for all individual
mappings.

closes #411

Author: gouttegd

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Add `composed entity expression` as a new value in the `EntityType` enumeration ([issue](https://github.com/mapping-commons/sssom/issues/402)).
 - Add `predicate_type` slot (previously defined but unused) to the `Mapping` and `MappingSet` classes ([issue](https://github.com/mapping-commons/sssom/issues/404)).
+- Add `similarity_measure` slot to the `MappingSet` class ([issue](https://github.com/mapping-commons/sssom/issues/411)).
 - TBD
 
 ## SSSOM version 1.0.0

src/docs/spec-model.md

@@ -57,7 +57,8 @@ For convenience, here is the current list of propagatable slots:
 * `subject_source`,
 * `subject_source_version`,
 * `subject_type`,
-* `predicate_type`.
+* `predicate_type`,
+* `similarity_measure`.
 
 When a mapping set object has a value in one of its propagatable slots, this MUST be interpreted as if all mappings within the set had that same value in their corresponding slot. For example, if a set has the value _foo_ in its `mapping_tool` slot, all the mappings in that set MUST be treated as if they had the value _foo_ in their `mapping_tool` slot.
 

src/sssom_schema/schema/sssom_schema.yaml

@@ -235,6 +235,7 @@ slots:
     see_also:
       - https://github.com/mapping-commons/sssom/issues/143
       - https://github.com/mapping-commons/sssom/blob/master/examples/schema/predicate-types.sssom.tsv
+    instantiates: sssom:Propagatable
     annotations:
       propagated: true
     examples:
@@ -643,6 +644,9 @@ slots:
       To make processing this field as unambiguous as possible, we recommend using 
       wikidata CURIEs, but the type of this field is deliberately unspecified.
     range: string
+    instantiates: sssom:Propagatable
+    annotations:
+      propagated: true
     examples:
       - value: https://www.wikidata.org/entity/Q865360
         description: the Wikidata IRI for the Jaccard index measure).
@@ -740,6 +744,7 @@ classes:
     - object_match_field
     - subject_preprocessing
     - object_preprocessing
+    - similarity_measure
     - see_also
     - issue_tracker
     - other