feat(cql2-text): add array predicate support (A_EQUALS, A_CONTAINS, A_CONTAINEDBY, A_OVERLAPS)

- Add 'a_containedBy' key to ARRAY_PREDICATES_MAP in cql2.py to match the
  camelCase used in CQL2-JSON (spec-compliant); the lowercase key is retained
  for the text parser
- Add array_predicate rule to the CQL2-text grammar: A_EQUALS, A_CONTAINS,
  A_CONTAINEDBY, A_OVERLAPS with two array_arg operands
- Inline empty_array and array as atom alternatives so LALR(1) can unambiguously
  parse '(1, 2, 3)' vs '(x)' by lookahead on the comma after the first element
- Add binary_array_predicate, array, and empty_array transformer methods to
  CQLTransformer; import ARRAY_PREDICATES_MAP from pygeofilter.cql2
- Add four tests: A_EQUALS/A_CONTAINS/A_OVERLAPS with a literal array and
  A_EQUALS with an empty array

Author: constantinius

pygeofilter/cql2.py

@@ -56,6 +56,7 @@
     "a_equals": ast.ArrayEquals,
     "a_contains": ast.ArrayContains,
     "a_containedby": ast.ArrayContainedBy,
+    "a_containedBy": ast.ArrayContainedBy,
     "a_overlaps": ast.ArrayOverlaps,
 }
 

pygeofilter/parsers/cql2_text/grammar.lark

@@ -61,6 +61,7 @@
           | "EXCLUDE"i                                                       -> exclude
           | spatial_predicate
           | temporal_predicate
+          | array_predicate
 
 
 ?temporal_predicate: expression _binary_temporal_predicate_func expression -> binary_temporal_predicate
@@ -95,6 +96,14 @@
                                | "S_EQUALS"i
 
 
+?array_predicate: _array_predicate_func "(" expression "," expression ")" -> binary_array_predicate
+
+!_array_predicate_func: "A_EQUALS"i
+                      | "A_CONTAINS"i
+                      | "A_CONTAINEDBY"i
+                      | "A_OVERLAPS"i
+
+
 ?expression: sum
 
 ?sum: product
@@ -109,6 +118,8 @@
      | attribute
      | literal
      | "-" atom                                                             -> neg
+     | "(" ")"                                                               -> empty_array
+     | "(" expression ("," expression)+ ")"                                  -> array
      | "(" expression ")"
 
 func.2: attribute "(" expression ("," expression)* ")" -> function

pygeofilter/parsers/cql2_text/parser.py

@@ -31,7 +31,7 @@
 from lark import Lark, logger, v_args
 
 from ... import ast, values
-from ...cql2 import SPATIAL_PREDICATES_MAP, TEMPORAL_PREDICATES_MAP
+from ...cql2 import ARRAY_PREDICATES_MAP, SPATIAL_PREDICATES_MAP, TEMPORAL_PREDICATES_MAP
 from ..iso8601 import ISO8601Transformer
 from ..wkt import WKTTransformer
 
@@ -124,6 +124,15 @@ def during_or_after(self, node, period):
     def after(self, node, dt):
         return ast.TimeAfter(node, dt)
 
+    def binary_array_predicate(self, func, lhs, rhs):
+        return ARRAY_PREDICATES_MAP[func.lower()](lhs, rhs)
+
+    def array(self, *items):
+        return list(items)
+
+    def empty_array(self):
+        return []
+
     def binary_spatial_predicate(self, op, lhs, rhs):
         op = op.lower()
         return SPATIAL_PREDICATES_MAP[op](lhs, rhs)

tests/parsers/cql2_text/test_parser.py

@@ -477,3 +477,23 @@ def test_not_eq():
     assert result == ast.Not(
         ast.Equal(ast.Attribute("attr"), 2)
     )
+
+
+def test_array_equals():
+    result = parse("A_EQUALS(attr, (1, 2, 3))")
+    assert result == ast.ArrayEquals(ast.Attribute("attr"), [1, 2, 3])
+
+
+def test_array_contains():
+    result = parse("A_CONTAINS(attr, (1, 2, 3))")
+    assert result == ast.ArrayContains(ast.Attribute("attr"), [1, 2, 3])
+
+
+def test_array_overlaps():
+    result = parse("A_OVERLAPS(attr, (1, 2, 3))")
+    assert result == ast.ArrayOverlaps(ast.Attribute("attr"), [1, 2, 3])
+
+
+def test_array_empty():
+    result = parse("A_EQUALS(attr, ())")
+    assert result == ast.ArrayEquals(ast.Attribute("attr"), [])