private IReadOnlyCollection <BooleanExpressionToken> ReduceParenTokens(IReadOnlyCollection <BooleanExpressionToken> tokens)
{
var cursor = new BooleanExpressionTokenReaderCursor {
Tokens = tokens.ToList()
};
List <BooleanExpressionToken> allTokens = new List <BooleanExpressionToken>();
while (cursor.Read(out var token))
{
if (token is OpenParenToken)
{
var innerTokens = ReadUntilClosingParen(cursor);
var parenExpression = new BooleanParenExpression {
InnerExpression = new BooleanExpressionTokenReader().CreateBooleanExpressionFromTokens(innerTokens)
};
var reduced = new ReducedToken {
ReducedExpression = parenExpression
};
allTokens.Add(reduced);
}
else
{
allTokens.Add(token);
}
}
return(allTokens);
}
private IReadOnlyCollection <BooleanExpressionToken> ReadUntilClosingParen(BooleanExpressionTokenReaderCursor cursor)
{
List <BooleanExpressionToken> innerTokens = new List <BooleanExpressionToken>();
var currentDepth = 1;
while (cursor.Read(out var token))
{
if (token is OpenParenToken)
{
currentDepth++;
}
if (token is CloseParenToken)
{
currentDepth--;
if (currentDepth == 0)
{
return(innerTokens); //don't add the closing paren to the inner tokens.
}
}
innerTokens.Add(token);
}
return(innerTokens);
}
private IReadOnlyCollection <BooleanExpressionToken> ReduceScalarTokens(IReadOnlyCollection <BooleanExpressionToken> tokens)
{
var cursor = new BooleanExpressionTokenReaderCursor {
Tokens = tokens.ToList()
};
List <BooleanExpressionToken> allTokens = new List <BooleanExpressionToken>();
while (cursor.Read(out var token))
{
if (token is NegationToken)
{
var reducedScalar = new ReducedScalarToken();
cursor.Read(out var negatedToken);
if (negatedToken is ReducedParenToken _reduced)
{
reducedScalar.ReducedExpression = _reduced.ReducedExpression;
allTokens.Add(reducedScalar);
continue;
}
if (negatedToken is VariableReference)
{
reducedScalar.ReducedExpression = new BooleanExpressionTokenReader().ReadScalar(negatedToken);
allTokens.Add(reducedScalar);
continue;
}
throw new ArgumentException("Unsupported use of unary not");
}
else if (token is VariableReference || token is DecimalLiteral || token is StringLiteral || token is IntegerLiteral || token is GuidLiteral)
{
allTokens.Add(new ReducedScalarToken {
ReducedExpression = new BooleanExpressionTokenReader().ReadScalar(token)
});
}
else
{
allTokens.Add(token);
}
}
return(allTokens);
}
private IReadOnlyCollection <BooleanExpressionToken> ReduceComparisonTokens(IReadOnlyCollection <BooleanExpressionToken> tokens)
{
var cursor = new BooleanExpressionTokenReaderCursor {
Tokens = tokens.ToList()
};
List <BooleanExpressionToken> allTokens = new List <BooleanExpressionToken>();
//BooleanExpression comparisonLeftScope = null;
while (cursor.Read(out var token))
{
if (token is ComparisonOperatorToken comparison)
{
if (!allTokens.Any())
{
throw new ArgumentException("Expect left operand for comparison.");
}
var success = cursor.Read(out var rightToken);
if (!success)
{
throw new ArgumentException("No right operand for comparison.");
}
var pop = (ReducedScalarToken)allTokens.Last();
allTokens.Remove(pop);
allTokens.Add(new ReducedScalarToken
{
ReducedExpression = new ComparisonExpression
{
Left = pop.ReducedExpression,
ComparisonType = comparison.ComparisonType,
Right = ((ReducedToken)rightToken).ReducedExpression
}
});
}
else
{
allTokens.Add(token);
}
}
return(allTokens);
}
private IReadOnlyCollection <BooleanExpressionToken> ReduceBooleanBinaryTokens(IReadOnlyCollection <BooleanExpressionToken> tokens)
{
var cursor = new BooleanExpressionTokenReaderCursor {
Tokens = tokens.ToList()
};
List <BooleanExpressionToken> allTokens = new List <BooleanExpressionToken>();
while (cursor.Read(out var token))
{
if (token is BooleanBinaryToken logicGateToken)
{
if (!allTokens.Any())
{
throw new ArgumentException("Expect left operand for boolean binary.");
}
var success = cursor.Read(out var rightToken);
if (!success)
{
throw new ArgumentException("No right operand for logic gate.");
}
var pop = (ReducedScalarToken)allTokens.Last();
allTokens.Remove(pop);
allTokens.Add(new ReducedScalarToken
{
ReducedExpression = new BooleanBinaryExpression
{
Left = pop.ReducedExpression,
GateType = logicGateToken.GateType,
Right = ((ReducedToken)rightToken).ReducedExpression
}
});
}
else
{
allTokens.Add(token);
}
}
return(allTokens);
}