init package:base-prelude

Return all the elements of a list except the last one. The list must be non-empty.
>>> init [1, 2, 3]
[1,2]

>>> init [1]
[]

>>> init []
*** Exception: Prelude.init: empty list
The inits function returns all initial segments of the argument, shortest first. For example,
>>> inits "abc"
["","a","ab","abc"]
Note that inits has the following strictness property: inits (xs ++ _|_) = inits xs ++ _|_ In particular, inits _|_ = [] : _|_
Pi: Punctuation, Initial quote
The thread is blocked on an MVar, but there are no other references to the MVar so it can't ever continue.
The thread is waiting to retry an STM transaction, but there are no other references to any TVars involved, so it can't ever continue.
The FiniteBits class denotes types with a finite, fixed number of bits.
Return the number of bits in the type of the argument. The actual value of the argument is ignored. Moreover, finiteBitSize is total, in contrast to the deprecated bitSize function it replaces.
finiteBitSize = bitSize
bitSizeMaybe = Just . finiteBitSize
True if the argument is an IEEE infinity or negative infinity