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exists                                                           (Lib)
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exists : ('a -> bool) -> 'a list -> bool

SYNOPSIS
Check if a predicate holds somewhere in a list.

KEYWORDS
list, predicate, search

DESCRIBE
An invocation {exists P l} returns true if {P} holds of some element of {l}.
Since there are no elements of {[]}, {exists P []} always returns {false}.

FAILURE
When searching for an element of {l} that {P} holds of, it may happen
that an application of {P} to an element of {l} raises an
exception. In that case, {exists P l} raises an exception.

EXAMPLE

- exists (fn i => i mod 2 = 0) [1,3,4];
> val it = true : bool

- exists (fn _ => raise Fail "") [];
> val it = false : bool

- exists (fn _ => raise Fail "") [1];
! Uncaught exception:
! Fail  ""




SEEALSO
Lib.all, Lib.first, Lib.tryfind.

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