Test for issue #31.

tests/func/regressions/test_issue31_glr_drop_parses_on_lexical_ambiguity.py

@@ -0,0 +1,28 @@
+from parglare import Grammar, GLRParser
+
+
+def test_issue31_glr_drop_parses_on_lexical_ambiguity():
+    grammar = """
+    model: element+;
+    element: title
+           | table_with_note
+           | table_with_title;
+    table_with_title: table_title table_with_note;
+    table_with_note: table note*;
+
+    terminals
+    title: /title/;   // <-- This is lexically ambiguous with the next.
+    table_title: /title/;
+    table: "table";
+    note: "note";
+    """
+
+    # this input should yield 4 parse trees.
+    input = "title table title table"
+
+    g = Grammar.from_string(grammar)
+    parser = GLRParser(g, debug=True, debug_colors=True)
+    results = parser.parse(input)
+
+    # We should have 4 solutions for the input.
+    assert len(results) == 4