Fix negation with AND (#39)

There was a problem with `not cubic` and `not tree`.

Author: mdbrnowski

src/graphreveal/__init__.py

@@ -3,7 +3,7 @@
 
 from platformdirs import user_data_dir
 
-__version__ = "0.2.1"
+__version__ = "0.2.2"
 
 DATABASE_PATH = os.path.join(
     user_data_dir(appname="graphreveal", appauthor="graphreveal"), "graphs.db"

src/graphreveal/translator/QueryTranslator.py

@@ -32,7 +32,7 @@ def visitSimpleExpr(self, ctx: QueryParser.SimpleExprContext):
         return self.visitChildren(ctx)
 
     def visitNotExpr(self, ctx: QueryParser.NotExprContext):
-        return "NOT " + self.visitChildren(ctx)
+        return "NOT (" + self.visitChildren(ctx) + ")"
 
     def visitNumEntityProperty(self, ctx: QueryParser.NumEntityPropertyContext):
         num = ctx.INTEGER().getText()

tests/test_query_results.py

@@ -19,6 +19,7 @@
         ("7 vertices, eulerian", 37),
         ("5 vertices, connected, planar", 20),
         ("5 vertices, tree", 3),
+        ("3 vertices, not tree", 3),
         ("5 vertices, 2 components", 8),
         ("3 edges, no isolated vertices", 5),
         ("1 vertex, hamiltonian", 1),