public void TestParserProducesAValue()
{
// Create an instance of our language grammar and set handlers for its rules.
LanguageGrammar<Expression> g = new LanguageGrammar<Expression>();
g.DivideRule.Action = (e1, e2) => Expression.Divide(e1, e2);
g.DoubleLiteralRule.Action = (d) => Expression.Constant(d);
g.IntLiteralRule.Action = (i) => Expression.Constant(i);
g.StringLiteralRule.Action = (s) => Expression.Constant(s);
g.MinusRule.Action = (e1, e2) => Expression.Subtract(e1, e2);
g.ModRule.Action = (e1, e2) => Expression.Modulo(e1, e2);
g.MultiplyRule.Action = (e1, e2) => Expression.Multiply(e1, e2);
g.NegateRule.Action = (e) => Expression.Negate(e);
g.PlusRule.Action = (e1, e2) => Expression.Add(e1, e2);
g.VariableRefRule.SetStatefulAction<ParserState>((s, name) => s.GetVariable(name));
// Spin up a parser for our language.
// TODO: Package this up and simplify it.
var expressionHelper = new ExpressionHelper();
var classifierSession = new TerminalClassifierSession<char, ParserState, int>()
.AddSkipTerminal(new Terminal<char> {Name = "Whitespace", InitialState = RegexCharNFABuilder.RegexCompiler(@"\s+")})
.CurrentCharExprIs(x => x.CurrentChar())
.GetFromMarkExprIs(x => x.GetFromMarkedPos())
.HasCurrentCharExprIs(x => x.HasCurrentChar())
.MarkPosExprIs(x => x.MarkPos())
.MoveNextCharExprIs(x => x.MoveNextChar())
.UnmarkPosExprIs(x => x.UnmarkPos());
var parserGen = new ParserGenerator<char>(expressionHelper);
var parseTableBuilder = new LRParseTableBuilder();
var parseTable = parseTableBuilder.BuildParseTable(g);
var session = parserGen.NewSession<ParserState>()
.NonTerminalValueExprIs<object>(x => x.NonTerminalValue)
.TerminalValueExprIs<string>(x => x.TerminalStringValue)
.TerminalValueExprIs<int>(x => x.TerminalIntValue)
.TerminalValueExprIs<double>(x => x.TerminalDoubleValue)
.TerminalIs(x=>x.Terminal)
.NonTerminalIs(x=>x.NonTerminal)
.IncludeSymbols(true)
.DebugOutputIs(x=>Debug.WriteLine(x))
.Generate("LanguageParser", parseTable, classifierSession);
// At this point, session is an Expression<ParserState,int> representing our parser.
// We can compile it into a delegate or a MethodBuilder. For the examples, we'll use a delegate.
var compiler = session.Compile();
// Create a parser state object and initialize it.
ParserState ps = new ParserState("x*y + 2.0");
ps.SetParameters(
Expression.Parameter(typeof(double), "x"),
Expression.Parameter(typeof(double), "y"));
Assert.AreEqual(0, compiler(ps));
Expression body = (Expression)ps.NonTerminalValue;
Expression<Func<double, double, double>> lambda = Expression.Lambda<Func<double,double,double>>
(body, ps.Variables["x"], ps.Variables["y"]);
var f = lambda.Compile();
Assert.AreEqual(12.0, f(5.0, 2.0));
Assert.AreEqual(2.0, f(0.0, 1.0));
}
public void TestQuotedStringValue()
{
LanguageGrammar<string> g = new LanguageGrammar<string>();
g.StringLiteralRule.Action = (s) => s;
// Spin up a parser for our language.
// TODO: Package this up and simplify it.
var expressionHelper = new ExpressionHelper();
//var classifierGen = new TerminalClassifier<char>();
var classifierSession = new TerminalClassifierSession<char, ParserState, int>()
.AddSkipTerminal(new Terminal<char> { Name = "Whitespace", InitialState = RegexCharNFABuilder.RegexCompiler(@"\s+") })
.CurrentCharExprIs(x => x.CurrentChar())
.GetFromMarkExprIs(x => x.GetFromMarkedPos())
.HasCurrentCharExprIs(x => x.HasCurrentChar())
.MarkPosExprIs(x => x.MarkPos())
.MoveNextCharExprIs(x => x.MoveNextChar())
.UnmarkPosExprIs(x => x.UnmarkPos());
var parserGen = new ParserGenerator<char>(expressionHelper);
var parseTableBuilder = new LRParseTableBuilder();
var parseTable = parseTableBuilder.BuildParseTable(g);
var session = parserGen.NewSession<ParserState>()
.NonTerminalValueExprIs<object>(x => x.NonTerminalValue)
.TerminalValueExprIs<string>(x => x.TerminalStringValue)
.TerminalValueExprIs<int>(x => x.TerminalIntValue)
.TerminalValueExprIs<double>(x => x.TerminalDoubleValue)
.TerminalIs(x => x.Terminal)
.NonTerminalIs(x => x.NonTerminal)
.IncludeSymbols(true)
.UseDefaultValue(true)
.DebugOutputIs(x => Debug.WriteLine(x))
.Generate("LanguageParser", parseTable, classifierSession);
// At this point, session is an Expression<ParserState,int> representing our parser.
// We can compile it into a delegate or a MethodBuilder. For the examples, we'll use a delegate.
var compiler = session.Compile();
ParserState ps = new ParserState("\"This is a quoted string\"");
Assert.AreEqual(0, compiler(ps));
Assert.AreEqual("This is a quoted string", ps.NonTerminalValue);
ps = new ParserState("\"Here are some \\t escape characters\\r\\netc...\"");
Assert.AreEqual(0, compiler(ps));
Assert.AreEqual("Here are some \t escape characters\r\netc...", ps.NonTerminalValue);
ps = new ParserState("\"And more \\\\ escape \\\" characters\"");
Assert.AreEqual(0, compiler(ps));
Assert.AreEqual("And more \\ escape \" characters", ps.NonTerminalValue);
}
public void TestParserSucceedsWithoutAValue()
{
LanguageGrammar<Expression> g = new LanguageGrammar<Expression>();
// Spin up a parser for our language.
// TODO: Package this up and simplify it.
var expressionHelper = new ExpressionHelper();
//var classifierGen = new TerminalClassifier<char>();
var classifierSession = new TerminalClassifierSession<char, ParserState, int>()
.CurrentCharExprIs(x => x.CurrentChar())
.GetFromMarkExprIs(x => x.GetFromMarkedPos())
.HasCurrentCharExprIs(x => x.HasCurrentChar())
.MarkPosExprIs(x => x.MarkPos())
.MoveNextCharExprIs(x => x.MoveNextChar())
.UnmarkPosExprIs(x => x.UnmarkPos());
var parserGen = new ParserGenerator<char>(expressionHelper);
var parseTableBuilder = new LRParseTableBuilder();
var parseTable = parseTableBuilder.BuildParseTable(g);
var session = parserGen.NewSession<ParserState>()
.NonTerminalValueExprIs<object>(x => x.NonTerminalValue)
.TerminalValueExprIs<string>(x => x.TerminalStringValue)
.TerminalValueExprIs<int>(x => x.TerminalIntValue)
.TerminalValueExprIs<double>(x => x.TerminalDoubleValue)
.TerminalIs(x => x.Terminal)
.NonTerminalIs(x => x.NonTerminal)
.IncludeSymbols(true)
.UseDefaultValue(true)
.DebugOutputIs(x => Debug.WriteLine(x))
.Generate("LanguageParser", parseTable, classifierSession);
// At this point, session is an Expression<ParserState,int> representing our parser.
// We can compile it into a delegate or a MethodBuilder. For the examples, we'll use a delegate.
var compiler = session.Compile();
// Create a parser state object and initialize it.
ParserState ps = new ParserState("x*y+2.0");
Assert.AreEqual(0, compiler(ps));
}