ExpressionType.Optional Field
Definition
Important
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Mark a sub-expression as optional.
public const string Optional;val mutable Optional : stringPublic Const Optional As String Field Value
Remarks
When an expression is being processed, optional creates a disjunction where the expression is both included and not included with the rest of the expression. This is a simple way to express this common relationship. By generating both clauses then matching the expression can be more specific when the optional expression is true.