public Either <ParsingError, CellValueCalculator> TryApplyBinaryOperator(
string operatorChars,
CellValueCalculator secondArgument,
FormulaParameters parameters)
{
if ((operatorChars == "&&" || operatorChars == "||") &&
(ResultType != typeof(bool) || secondArgument.ResultType != typeof(bool)))
{
return(Left(new ParsingError($"Operator '{operatorChars}' cannot be applied to operands of type '{ResultType.Name}' and '{secondArgument.ResultType}'")));
}
var op = KnownBinaryOperations[operatorChars];
var localThis = this;
return
(from resultType in TryToDeduceResultingType(operatorChars, ResultType, secondArgument.ResultType)
from leftOperand in localThis.TryCastTo(resultType)
from rightOperand in secondArgument.TryCastTo(resultType)
select CombineCalculators(
op.ResultIsBoolean?typeof(bool) : resultType,
parameters,
op.Expression(leftOperand.CalculateExpression, rightOperand.CalculateExpression),
$"{leftOperand.CalculateExpression}{operatorChars}{rightOperand.CalculateExpression}",
leftOperand,
rightOperand));
}
private static Parser <CellValueCalculator> ArithmeticExpressionParser(
Parser <CellValueCalculator> elementParser,
FormulaParameters parameters,
params string[] operationLexems)
=>
from elements in UniformList(elementParser, Operator(operationLexems))
from combinedCalculator in FoldBinaryOperatorsList(elements, parameters).StopParsingIfFailed()
select combinedCalculator;
private static Parser <CellValueCalculator> FoldBinaryOperatorsList(
ParsedUniformList <CellValueCalculator, string> operands,
FormulaParameters parameters) =>
operands
.TailPairs
.Aggregate(
Right <ParsingError, CellValueCalculator>(operands.FirstElement),
(valueCalculatorOrError, pair) =>
valueCalculatorOrError.FlatMap(calculator => calculator.TryApplyBinaryOperator(pair.Link, pair.Right, parameters)))
.Fold(
error => Failure <CellValueCalculator>(textInput => textInput.MakeErrors(error, null)),
Success);
private static Parser <CellValueCalculator> CreateFormulaParser(
Parser <CellValueCalculator> literal,
Parser <CellValueCalculator> propertyAccessor,
TryParse <IReadOnlyCollection <MethodInfo> > tryGetFunctionByName,
FormulaParameters formulaParameters)
{
Parser <CellValueCalculator> resultingParser = null;
// ReSharper disable once AccessToModifiedClosure
var parameterList = from openingBrace in Lexem("(")
from arguments in Optional(UniformList(resultingParser, Lexem(",")))
from closingBrace in Lexem(")")
select arguments.Map(a => a.Elements).OrElse(Enumerable.Empty <CellValueCalculator>());
TryParse <Maybe <IReadOnlyCollection <MethodInfo> > > tryGetFunctionOrConditionExpressionByName =
(string name, out Maybe <IReadOnlyCollection <MethodInfo> > result) =>
{
result = tryGetFunctionByName(name, out var methodInfos) ? Some(methodInfos) : None;
return(result.Map(_ => true).OrElse(name == "Iif" || name == "If"));
};
var functionCall = from functionName in Identifier
from lazyParameters in parameterList
from methodInfos in functionName.Try(tryGetFunctionOrConditionExpressionByName, n => $"Unknown function: '{n}'").StopParsingIfFailed()
let parameters = lazyParameters.ToArray()
from methodInfo in PickFunctionOverload(functionName, methodInfos, parameters).StopParsingIfFailed()
from arguments in methodInfo
.Map(mi => MakeFunctionCallArguments(mi, parameters))
.OrElse(() => MakeIifFunctionCallArguments(parameters))
.StopParsingIfFailed()
select CombineCalculators(
methodInfo.Map(mi => mi.ReturnType).OrElse(() => arguments[1].Type),
formulaParameters,
methodInfo.Map(mi => (Expression)Expression.Call(mi, arguments))
.OrElse(() => Expression.Condition(arguments[0], arguments[1], arguments[2])),
$"{functionName}({string.Join(",", parameters.Select(c => c.CalculateExpression))})",
parameters);
// ReSharper disable once AccessToModifiedClosure
var bracedExpression = from openingBrace in Lexem("(")
from internalExpression in resultingParser
from closingBrace in Lexem(")")
select internalExpression;
var multiplier = from optionalSign in Optional(Lexem("-", "+"))
from valueCalculator in literal.Or(bracedExpression).Or(functionCall).Or(propertyAccessor)
from adjustedCalculator in AsParser(valueCalculator.TryGiveSign(optionalSign.OrElse(string.Empty)))
select adjustedCalculator;
resultingParser = CreateFormulaParserCore(multiplier, formulaParameters);
return(resultingParser);
}
private static Expression GetPrecalculatedAggregatedValue(
Type resultType,
FormulaParameters parameters,
string aggregatedValueKey)
{
// return (resultType)parameters.AggregatedValues[aggregatedValueKey]
return(Expression.Convert(
Expression.Property(
parameters.AggregatedValues,
"Item",
Expression.Constant(aggregatedValueKey, typeof(string))),
resultType));
}
public ColumnFormulaBuilder(
Type rowDataType,
TryParse <Type> tryGetPropertyTypeByName,
TryParse <IReadOnlyCollection <MethodInfo> > tryGetFunctionsByName)
{
var parameters = new FormulaParameters(rowDataType);
_formulaCompiler = new FormulaExpressionsCompiler(parameters);
var integerLiteral = NumericLiteral(new TryParse <int>(int.TryParse));
var decimalLiteral = NumericLiteral(new TryParse <decimal>(decimal.TryParse));
var dateTimeLiteral = ParsedQuotedLiteral(new TryParse <DateTime>(DateTime.TryParse));
var stringLiteral = QuotedLiteral.Select(Constant);
var literal = dateTimeLiteral.Or(stringLiteral).Or(integerLiteral).Or(decimalLiteral);
var quotedPropertyName = from openingBracket in Lexem("[")
from nameChars in Repeat(ch => ch != ']' && ch != '\r' && ch != '\n')
from closingBraket in Lexem("]")
select string.Join(
string.Empty,
nameChars
.Where(ch => ch != ' ' && ch != '\t')
.Select(ch => char.IsLetterOrDigit(ch) ? ch.ToString() : $"_char_{(int)ch}_"));
var propertyName = quotedPropertyName.Or(Identifier);
var propertyAccessor = from name in propertyName
from propertyType in name.Try(tryGetPropertyTypeByName, n => $"Unknown property: '{n}'").StopParsingIfFailed()
select new CellValueCalculator(propertyType, Expression.Property(parameters.CurrentRow, name));
var aggregatableExpression = CreateFormulaParser(literal, propertyAccessor, tryGetFunctionsByName, parameters);
var aggregatedPropertyAccessor = from openingBracket in Lexem("[")
from aggregationMethodText in Identifier
from colon in Lexem(":")
from aggregationMethod in aggregationMethodText.Try <AggregationMethod>(
Enum.TryParse,
m => $"Invalid aggregation method {m} specified: only '" +
string.Join("', '", Enum.GetNames(typeof(AggregationMethod)) +
"' are supported")).StopParsingIfFailed()
from calculator in aggregatableExpression
from closingBraket in Lexem("]")
select aggregationMethod == AggregationMethod.all
? calculator.All(_formulaCompiler)
: calculator.FirstOrLast(aggregationMethod, _formulaCompiler);
_formulaTextParser = CreateFormulaParser(
literal,
aggregatedPropertyAccessor.Or(propertyAccessor),
tryGetFunctionsByName,
parameters);
}
private static Parser <CellValueCalculator> CreateFormulaParserCore(
Parser <CellValueCalculator> multiplier,
FormulaParameters parameters)
{
var addend = ArithmeticExpressionParser(multiplier, parameters, "*", "/", "%");
var comparableExpression = ArithmeticExpressionParser(addend, parameters, "+", "-");
var equatableExpression = ArithmeticExpressionParser(comparableExpression, parameters, "<", "<=", ">", ">=");
var bitwiseAndableExpression = ArithmeticExpressionParser(equatableExpression, parameters, "==", "!=");
var bitwiseXorableExpression = ArithmeticExpressionParser(bitwiseAndableExpression, parameters, "&");
var bitwiseOrableExpression = ArithmeticExpressionParser(bitwiseXorableExpression, parameters, "^");
var logicalAndableExpression = ArithmeticExpressionParser(bitwiseOrableExpression, parameters, "|");
var logicalOrableExpression = ArithmeticExpressionParser(logicalAndableExpression, parameters, "&&");
return(ArithmeticExpressionParser(logicalOrableExpression, parameters, "||"));
}
public static CellValueCalculator CombineCalculators(
Type resultType,
FormulaParameters parameters,
Expression calculateExpression,
string aggregatedValueKey,
params CellValueCalculator[] calculators)
{
var allAggregatedValueCalculators = calculators.Aggregate(
AggregatedValueCalculators.Empty,
(combinedCalculators, calculator) => combinedCalculators.AddRange(calculator.AggregatedValuesCalculators));
return(!calculators.All(c => c._canBeAggregated)
? new CellValueCalculator(
resultType,
calculateExpression,
allAggregatedValueCalculators)
: new CellValueCalculator(
resultType,
GetPrecalculatedAggregatedValue(resultType, parameters, aggregatedValueKey),
allAggregatedValueCalculators.Insert(0, KeyValuePair.Create(aggregatedValueKey, calculateExpression)),
canBeAggregated: true));
}
public FormulaExpressionsCompiler(FormulaParameters formulaParameters)
{
Parameters = formulaParameters;
}