Output position info for various error return codes - close #10

spec/propane_spec.rb

@@ -359,6 +359,21 @@ EOF
     expect(results.status).to eq 0
   end
 
+  it "tracks position of parser errors" do
+    write_grammar <<EOF
+token a;
+token num /\\d+/;
+drop /\\s+/;
+Start -> a num Start;
+Start -> a num;
+EOF
+    build_parser
+    compile("spec/test_error_positions.d")
+    results = run
+    expect(results.stderr).to eq ""
+    expect(results.status).to eq 0
+  end
+
   it "allows creating a JSON parser" do
     write_grammar(File.read("spec/json_parser.propane"))
     build_parser

spec/test_d_parser_rule_from_multiple_states.d

@@ -12,6 +12,7 @@ unittest
     p_context_t context;
     p_context_init(&context, input);
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
+    assert(p_position(&context) == p_position_t(0, 1));
 
     input = "a b";
     p_context_init(&context, input);

spec/test_error_positions.d

@@ -0,0 +1,36 @@
+import testparser;
+import std.stdio;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "a 42";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+
+    input = "a\n123\na  a";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
+    assert(p_position(&context) == p_position_t(2, 3));
+
+    input = "12";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
+    assert(p_position(&context) == p_position_t(0, 0));
+
+    input = "a 12\n\nab";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_UNEXPECTED_INPUT);
+    assert(p_position(&context) == p_position_t(2, 1));
+
+    input = "a 12\n\na\n\n77\na   \xAA";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_DECODE_ERROR);
+    writeln(p_position(&context));
+    assert(p_position(&context) == p_position_t(5, 4));
+}