Add truth, is, and not functions

Author: sgillies

CHANGES

@@ -1,7 +1,13 @@
 Changes
 =======
 
-1.0b1 (2023-04-18)
+1.0rc1 (2023-04-18)
+------------------
+
+- The truth, is, and not functions from operators have been added to
+  the mapping of functions available in expressions.
+
+1.0b1 (2023-04-13)
 ------------------
 
 - Require pyparsing >= 3.0 (#29).

src/fio_planet/__init__.py

@@ -16,4 +16,4 @@
 
 """fio_planet: Fiona CLI plugins from Planet Labs."""
 
-__version__ = "1.0b1"
+__version__ = "1.0rc1"

src/fio_planet/features.py

@@ -47,7 +47,9 @@ def __getitem__(self, key):
         elif key in dir(shapely):
             return lambda g, *args, **kwargs: getattr(shapely, key)(g, *args, **kwargs)
         elif key in dir(shapely.ops):
-            return lambda g, *args, **kwargs: getattr(shapely.ops, key)(g, *args, **kwargs)
+            return lambda g, *args, **kwargs: getattr(shapely.ops, key)(
+                g, *args, **kwargs
+            )
         else:
             return (
                 lambda g, *args, **kwargs: getattr(g, key)(*args, **kwargs)

src/fio_planet/snuggs.py

@@ -60,6 +60,7 @@
     ZeroOrMore,
     alphanums,
     pyparsing_common,
+    replace_with,
 )
 
 __all__ = ["eval"]
@@ -125,6 +126,9 @@ class ExpressionError(SyntaxError):
     "!=": operator.ne,
     ">=": operator.ge,
     ">": operator.gt,
+    "truth": operator.truth,
+    "is": operator.is_,
+    "not": operator.not_,
 }
 
 
@@ -149,9 +153,9 @@ def compose(f, g):
     "itemgetter": operator.itemgetter,
 }
 
-nil = Keyword("null").set_parse_action(lambda source, loc, toks: None)
-true = Keyword("true").set_parse_action(lambda source, loc, toks: True)
-false = Keyword("false").set_parse_action(lambda source, loc, toks: False)
+nil = Keyword("null").set_parse_action(replace_with(None))
+true = Keyword("true").set_parse_action(replace_with(True))
+false = Keyword("false").set_parse_action(replace_with(False))
 
 
 def resolve_var(source, loc, toks):

tests/test_snuggs.py

@@ -0,0 +1,39 @@
+# Python module tests
+#
+# Copyright 2023 Planet Labs PBC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests of the snuggs module."""
+
+import pytest
+
+from fio_planet import snuggs
+
+
+@pytest.mark.parametrize("arg", ["''", "null", "false", 0])
+def test_truth_false(arg):
+    """Expression is not true."""
+    assert not snuggs.eval(f"(truth {arg})")
+
+
+@pytest.mark.parametrize("arg", ["'hi'", "true", 1])
+def test_truth(arg):
+    """Expression is true."""
+    assert snuggs.eval(f"(truth {arg})")
+
+
+@pytest.mark.parametrize("arg", ["''", "null", "false", 0])
+def test_not(arg):
+    """Expression is true."""
+    assert snuggs.eval(f"(not {arg})")