Allow dashes in context dimension names (#255)

It's quite common to name multi-word keys with dashes instead of
underscores. Let's allow dashes in the context dimension names as
well.

docs/context.rst

@@ -45,7 +45,7 @@ supported operators consult the following grammar outline::
     expression ::= dimension binary_operator values
     expression ::= dimension unary_operator
     expression ::= 'true' | 'false'
-    dimension ::= [[:alnum:]]+
+    dimension ::= [[:alnum:-]]+
     binary_operator ::= '==' | '!=' | '<' | '<=' | '>' | '>=' |
         '~=' | '~!=' | '~<' | '~<=' | '~>' | '~>=' | '~' | '!~'
     unary_operator ::= 'is defined' | 'is not defined'

fmf/context.py

@@ -397,15 +397,15 @@ def _op_core(self, dimension_name, values, comparator):
     # Triple expression: dimension operator values
     # [^=].* is necessary as .+ matches '= something'
     re_expression_triple = re.compile(
-        r"(\w+)"
+        r"([\w-]+)"
         + r"\s*("
         + r"|".join(
             [key for key in operator_map if key not in ["is defined", "is not defined"]])
         + r")\s*"
         + r"([^=].*)")
     # Double expression: dimension operator
     re_expression_double = re.compile(
-        r"(\w+)" + r"\s*(" + r"|".join(["is defined", "is not defined"]) + r")"
+        r"([\w-]+)" + r"\s*(" + r"|".join(["is defined", "is not defined"]) + r")"
         )
 
     # Simple boolean value

tests/unit/test_context.py

@@ -535,6 +535,10 @@ def test_split_expression(self):
         assert Context.split_expression("dim < value , second") == (
             "dim", "<", ["value", "second"])
         assert Context.split_expression("true") == (None, True, None)
+        assert Context.split_expression("provision-method == local") == (
+            "provision-method", "==", ["local"])
+        assert Context.split_expression("provision-method is defined") == (
+            "provision-method", "is defined", None)
 
     def test_parse_rule(self):
         """ Rule parsing """