public void PracticalExample_MathematicalFormula()
{
#region Composite
var VALUE = new PrioritizedChoice(
new CapturingGroup("VALUE",
new OneOrMore(new CharacterClass {
ClassExpression = "[0-9]"
})
)
,
new Sequence(
new Literal {
MatchText = "("
},
new RecursionCall("ParethesisFunction")
)
.Sequence(new Literal {
MatchText = ")"
})
);
var PRODUCT = new Sequence(
VALUE,
new Sequence(
new CapturingGroup("SYMBOL",
new PrioritizedChoice(
new Literal {
MatchText = "*"
},
new Literal {
MatchText = "/"
}
)
),
VALUE
).Star()
);
var SUM = new Sequence(
PRODUCT,
new Sequence(
new CapturingGroup("SYMBOL",
new PrioritizedChoice(
new Literal {
MatchText = "+"
},
new Literal {
MatchText = "-"
}
)
),
PRODUCT
).Star()
);
AExpression EXPRESSION = new RecursionCreate("ParethesisFunction", new CapturingGroup("EXPRESSION", SUM));
#endregion
var input = "((((12/3)+5-2*(81/9))+1))";
var bytes = Encoding.UTF8.GetBytes(input);
var iterator = new ByteInputIterator(bytes);
var visitor = new NpegParserVisitor(iterator);
EXPRESSION.Accept(visitor);
Assert.IsTrue(visitor.IsMatch);
AstNode node = visitor.AST;
Assert.IsTrue(node.Token.ValueAsString(iterator) == input);
}