private static Grammar MakeParser()
{
// Literals
var ws = Terminals.WhiteSpace.Repeat(0);
var comma = ws.Then(Terminals.Set(','), ws);
var subExpressionAccess = ws.Then(Terminals.Set('.'), ws);
var number = new NumberParser
{
AllowDecimal = true,
AllowExponent = true,
AllowSign = true,
ValueType = typeof(float)
};
var identifier = Terminals.Letter.Or(Terminals.Set(_identifierAllowedCharacters))
.Then(Terminals.LetterOrDigit.Or(Terminals.Set(_identifierAllowedCharacters)).Repeat(0));
// Expressions
var expression = new UnaryParser();
var subExpression = expression.Named(ElementAST.SubExpressionRoot)
.Then(subExpressionAccess, identifier.Named(ElementAST.SubExpressionName));
var arguments = expression.Named(ElementAST.CallArgument).Repeat(0).SeparatedBy(comma);
var call = expression.Named(ElementAST.Callee)
.Then(ws, Terminals.Set('('), ws, arguments.Named(ElementAST.CallArguments), ws,
Terminals.Set(')'));
expression.Inner = new AlternativeParser(
number.Named(ElementAST.NumberExpression),
identifier.Named(ElementAST.VariableExpression),
subExpression.Named(ElementAST.SubExpression),
call.Named(ElementAST.CallExpression)
);
// Functions
var portType = ws.Then(Terminals.Literal(":"), ws, identifier.Named(ElementAST.PortType)).Optional();
var port = identifier.Named(ElementAST.PortName).Then(portType).Named(ElementAST.Port);
var ports = port.Repeat(0).SeparatedBy(comma);
var fnInputs = Terminals.Set('(')
.Then(ws, ports.Named(ElementAST.FunctionInputs), ws, Terminals.Set(')')).Optional();
var fnOutputs = Terminals.Literal("->").Then(ws, ports.Named(ElementAST.FunctionOutputs)).Or(portType);
var fnSignature = identifier.Named(ElementAST.FunctionName).Then(ws, fnInputs, ws, fnOutputs, ws);
// Statements
var statement = new UnaryParser();
var body = Terminals.Set('{').Then(ws, statement.Then(ws).Repeat(0).Named(ElementAST.FunctionBody), ws,
Terminals.Set('}'));
var assign = Terminals.Set('=').Then(ws, expression.Named(ElementAST.AssignmentStatement), ws,
Terminals.Set(';'));
statement.Inner = fnSignature
.Then(body.Or(assign).Or(Terminals.Set(';').Named(ElementAST.TypeStatement)))
.Named(ElementAST.Statement);
var start = ws.Then(statement, ws).Repeat(0);
start.Until = Terminals.End;
return(new Grammar(start));
}
