Expression

References
[IoId("00000000-1369-45e5-9517-944544f770d8")] public sealed class Expression : IStorable
Represents an expression for a specific input output type.

Constructors

Expression

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public Expression(IReader reader)
Parameters:
reader (IReader)

Properties

CompilerCode

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public string CompilerCode { get; }
Gets the modified source code that was used to compile this expression.

Identity

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public static Expression Identity { get; }
Gets an identity expression for a single variable 'x'.

NaN

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public static Expression NaN { get; }
Gets an expression which always returns double.NaN.

Undeclareds

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public IEnumerable<string> Undeclareds { get; }
Iterate over all global variables in this expression. This expression probably cannot be evaluated unless a Resolver is supplied which provides values for all these globals.

UserCode

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public string UserCode { get; }
Gets the source code with which this expression is associated.

Zero

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public static Expression Zero { get; }
Gets an expression which immediately returns zero.

Methods

Constant

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public static Expression Constant(string code, object value)
Create an expression with a constant return value.
Parameters:
code (string)
value (object)

Evaluate

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public object Evaluate()
Evaluate this expression. If the expression relies on external variables, you cannot use this overload.
Returns: The result of the expression.

Evaluate

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public object Evaluate(Resolver resolver)
Evaluate this expression.
Parameters:
resolver (Resolver)Variable resolver. You only need a resolver if the expression contains undeclared variables.
Returns: The result of the expression.

EvaluateSafe

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public object EvaluateSafe()
Evaluate this expression. Any exceptions thrown during evaluation will be returned as a string instead.
Returns: Result of expression or a string describing why it failed.

EvaluateSafe

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public object EvaluateSafe(Resolver resolver)
Evaluate this expression. Any exceptions thrown during evaluation will be returned as a string instead.
Parameters:
resolver (Resolver)Variable resolver. You only need a resolver if the expression contains undeclared variables.
Returns: Result of expression or a string describing why it failed.

GetHashCode

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public override int GetHashCode()
Gets a hash for this expression.
Overrides: Object.GetHashCode
Explicit

IStorable.Store

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void IStorable.Store(IWriter writer)
Parameters:
writer (IWriter)
Implements: Store

HasUndeclareds

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public bool HasUndeclareds(params string[] ignoreList)
Test whether this expression has any undeclareds other than the provided list.
Parameters:
ignoreList (params string[])List of undeclared variable names to ignore.
Returns: True if there's at least one undeclared variable with a name not on the list.

ToString

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public override string ToString()
Gets a string description of this expression.
Overrides: Object.ToString

TryCreate

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public static Expression TryCreate(string userCode, out string message)
Try and create an expression. This method doesn't throw.
Parameters:
userCode (string)Expression code.
message (out string)Message in case of failure.
Returns: Expression or null.

TryCreate

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public static Expression TryCreate(string userCode)
Try and create an expression. This method doesn't throw.
Parameters:
userCode (string)Expression code.
Returns: Expression or null.

Variable

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public static Expression Variable(string name)
Create an expression with a direct variable lookup.
Parameters:
name (string)