Safe Haskell | Safe |
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# Signed integer types

This module provides signed integer types of unspecified width (`Int`

)
and fixed widths (`Int8`

, `Int16`

, `Int32`

and `Int64`

). All
arithmetic is performed modulo 2^n, where `n`

is the number of bits in
the type.

For coercing between any two integer types, use
`fromIntegral`

. Coercing word types (see Data.Word) to and
from integer types preserves representation, not sign.

The rules that hold for `Enum`

instances over a bounded type
such as `Int`

(see the section of the Haskell language report dealing with
arithmetic sequences) also hold for the `Enum`

instances over
the various `Int`

types defined here.

Right and left shifts by amounts greater than or equal to the width of
the type result in either zero or -1, depending on the sign of the
value being shifted. This is contrary to the behaviour in C, which is
undefined; a common interpretation is to truncate the shift count to
the width of the type, for example `1 << 32 == 1`

in some C
implementations.

data Int

data Int8

8-bit signed integer type

data Int16

16-bit signed integer type

data Int32

32-bit signed integer type