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));
}
public EbnfGrammar()
: base("ebnf")
{
DefineCommonNonTerminals = true;
GenerateSpecialSequences();
// terminals
AlternativeParser terminal_string = ("'" & (+Terminals.AnyChar).Until("'").WithName("value") & "'")
| ("\"" & (+Terminals.AnyChar).Until("\"").WithName("value") & "\"")
| ("’" & (+Terminals.AnyChar).Until("’").WithName("value") & "’");
SequenceParser special_sequence =
("?" & (+Terminals.AnyChar).Until("?").WithName("name") & "?").WithName("special sequence");
SequenceParser meta_identifier_terminal = Terminals.Letter & -(Terminals.LetterOrDigit | '_');
var integer = new NumberParser();
Parser old = DefaultSeparator;
DefaultSeparator = cws;
// nonterminals
var definition_list = new UnaryParser("definition list");
var single_definition = new UnaryParser("single definition");
var term = new UnaryParser("term");
var primary = new UnaryParser("primary");
var exception = new UnaryParser("exception");
var factor = new UnaryParser("factor");
var meta_identifier = new UnaryParser("meta identifier");
var syntax_rule = new UnaryParser("syntax rule");
var rule_equals = new UnaryParser("equals");
SequenceParser optional_sequence = ("[" & definition_list & "]").WithName("optional sequence");
SequenceParser repeated_sequence = ("{" & definition_list & "}").WithName("repeated sequence");
SequenceParser grouped_sequence = ("(" & definition_list & ")").WithName("grouped sequence");
// rules
meta_identifier.Inner = (+meta_identifier_terminal).SeparatedBy(ws);
primary.Inner = optional_sequence | repeated_sequence
| special_sequence | grouped_sequence
| meta_identifier | terminal_string.Named("terminal string") | null;
factor.Inner = ~(integer.Named("integer") & "*") & primary;
term.Inner = factor & ~("-" & exception);
exception.Inner = term;
single_definition.Inner = term & -("," & term);
definition_list.Inner = single_definition & -("|" & single_definition);
rule_equals.Inner = (Parser)"=" | ":=";
syntax_rule.Inner = meta_identifier & rule_equals & definition_list & ";";
Inner = cws & +syntax_rule & cws;
DefaultSeparator = old;
AttachEvents();
}
public void TestInt32Values()
{
var sample = "123,+123,-123";
var grammar = new Grammar();
var num = new NumberParser {
AllowSign = true, AllowDecimal = true, ValueType = typeof(int)
};
grammar.Inner = (+num.Named("str")).SeparatedBy(",");
var match = grammar.Match(sample);
Assert.True(match.Success, match.ErrorMessage);
Assert.Equal(new Int32[] { 123, 123, -123 }, match.Find("str").Select(m => (int)m.Value));
}
public void TestExponent()
{
var sample = "123E-02,123E+10,123.4567E+5,1234E2";
var grammar = new Grammar();
var num = new NumberParser {
AllowDecimal = true, AllowExponent = true
};
grammar.Inner = (+num.Named("str")).SeparatedBy(",");
var match = grammar.Match(sample);
Assert.True(match.Success, match.ErrorMessage);
Assert.Equal(new object[] { 123E-2M, 123E+10M, 123.4567E+5M, 1234E+2M }, match.Find("str").Select(m => num.GetValue(m)));
}
public void TestSign()
{
var sample = "123.4567,+123.4567,-123.4567";
var grammar = new Grammar();
var num = new NumberParser {
AllowSign = true, AllowDecimal = true
};
grammar.Inner = (+num.Named("str")).SeparatedBy(",");
var match = grammar.Match(sample);
Assert.True(match.Success, match.ErrorMessage);
Assert.Equal(new object[] { 123.4567M, 123.4567M, -123.4567M }, match.Find("str").Select(m => num.GetValue(m)));
}
public void TestDecimalValues()
{
var sample = "123.4567,+123.4567,-123.4567";
var grammar = new Grammar();
var num = new NumberParser {
AllowSign = true, AllowDecimal = true, ValueType = typeof(decimal)
};
grammar.Inner = (+num.Named("str")).SeparatedBy(",");
var match = grammar.Match(sample);
Assert.IsTrue(match.Success, match.ErrorMessage);
CollectionAssert.AreEquivalent(new Decimal[] { 123.4567M, 123.4567M, -123.4567M }, match.Find("str").Select(m => (decimal)m.Value));
}
