Add Grammar spec

spec/propane/grammar_spec.rb

@@ -0,0 +1,145 @@
+class Propane
+  describe Grammar do
+    it "parses a user grammar" do
+      input = <<EOF
+# Comment line
+
+module a.b;
+class Foobar;
+
+token while;
+
+token id
+  [a-zA-Z_][a-zA-Z_0-9]*;
+
+token token_with_code <<
+Code for the token
+>>
+
+tokenid token_with_no_pattern;
+
+drop \\s+;
+
+A -> B <<
+  a = 42;
+>>
+B -> C while id;
+B -> <<
+  b = 0;
+>>
+EOF
+      grammar = Grammar.new(input)
+      expect(grammar.classname).to eq "Foobar"
+      expect(grammar.modulename).to eq "a.b"
+
+      o = grammar.tokens.find {|token| token.name == "while"}
+      expect(o).to_not be_nil
+      expect(o.line_number).to eq 6
+      expect(o.id).to eq 0
+
+      o = grammar.patterns.find {|pattern| pattern.token == o}
+      expect(o).to_not be_nil
+      expect(o.pattern).to eq "while"
+      expect(o.line_number).to eq 6
+      expect(o.code_id).to be_nil
+      expect(o.code).to be_nil
+
+      o = grammar.tokens.find {|token| token.name == "id"}
+      expect(o).to_not be_nil
+      expect(o.line_number).to eq 8
+      expect(o.id).to eq 1
+
+      o = grammar.patterns.find {|pattern| pattern.token == o}
+      expect(o).to_not be_nil
+      expect(o.pattern).to eq "[a-zA-Z_][a-zA-Z_0-9]*"
+      expect(o.line_number).to eq 8
+      expect(o.code_id).to be_nil
+      expect(o.code).to be_nil
+
+      o = grammar.tokens.find {|token| token.name == "token_with_code"}
+      expect(o).to_not be_nil
+      expect(o.line_number).to eq 11
+      expect(o.id).to eq 2
+
+      o = grammar.patterns.find {|pattern| pattern.token == o}
+      expect(o).to_not be_nil
+      expect(o.pattern).to eq "token_with_code"
+      expect(o.line_number).to eq 11
+      expect(o.code_id).to eq 0
+      expect(o.code).to eq "Code for the token\n"
+
+      o = grammar.tokens.find {|token| token.name == "token_with_no_pattern"}
+      expect(o).to_not be_nil
+      expect(o.line_number).to eq 15
+
+      o = grammar.patterns.find {|pattern| pattern.token == o}
+      expect(o).to be_nil
+
+      o = grammar.patterns.find {|pattern| pattern.pattern == "\\s+"}
+      expect(o).to_not be_nil
+      expect(o.line_number).to eq 17
+      expect(o.token).to be_nil
+      expect(o.code_id).to be_nil
+      expect(o.code).to be_nil
+
+      expect(grammar.rules.size).to eq 3
+
+      o = grammar.rules[0]
+      expect(o.name).to eq "A"
+      expect(o.components).to eq %w[B]
+      expect(o.id).to eq 1
+      expect(o.line_number).to eq 19
+      expect(o.code).to eq "  a = 42;\n"
+
+      o = grammar.rules[1]
+      expect(o.name).to eq "B"
+      expect(o.components).to eq %w[C while id]
+      expect(o.id).to eq 2
+      expect(o.line_number).to eq 22
+      expect(o.code).to be_nil
+
+      o = grammar.rules[2]
+      expect(o.name).to eq "B"
+      expect(o.components).to eq []
+      expect(o.id).to eq 3
+      expect(o.line_number).to eq 23
+      expect(o.code).to eq "  b = 0;\n"
+    end
+
+    it "parses code segments with semicolons" do
+      input = <<EOF
+token code1 <<
+  a = b;
+  return c;
+>>
+
+token code2 <<
+  writeln("Hello there");
+>>
+
+tokenid token_with_no_pattern;
+EOF
+      grammar = Grammar.new(input)
+
+      o = grammar.tokens.find {|token| token.name == "code1"}
+      expect(o).to_not be_nil
+      expect(o.id).to eq 0
+      expect(o.line_number).to eq 1
+
+      o = grammar.patterns.find {|pattern| pattern.token == o}
+      expect(o).to_not be_nil
+      expect(o.code_id).to eq 0
+      expect(o.code).to eq "  a = b;\n  return c;\n"
+
+      o = grammar.tokens.find {|token| token.name == "code2"}
+      expect(o).to_not be_nil
+      expect(o.id).to eq 1
+      expect(o.line_number).to eq 6
+
+      o = grammar.patterns.find {|pattern| pattern.token == o}
+      expect(o).to_not be_nil
+      expect(o.code_id).to eq 1
+      expect(o.code).to eq %[  writeln("Hello there");\n]
+    end
+  end
+end