Eq package:basic-prelude
The
Eq class defines equality (
==) and inequality
(
/=). All the basic datatypes exported by the
Prelude
are instances of
Eq, and
Eq may be derived for any
datatype whose constituents are also instances of
Eq.
Minimal complete definition: either
== or
/=.
Evaluate each monadic action in the structure from left to right, and
collect the results. For a version that ignores the results see
sequence_.
Evaluate each action in the structure from left to right, and and
collect the results. For a version that ignores the results see
sequenceA_.
Evaluate each action in the structure from left to right, and ignore
the results. For a version that doesn't ignore the results see
sequenceA.
General-purpose finite sequences.
The value of seq a b is bottom if a is bottom, and
otherwise equal to b. seq is usually introduced to
improve performance by avoiding unneeded laziness.
A note on evaluation order: the expression seq a b does
not guarantee that a will be evaluated before
b. The only guarantee given by seq is that the both
a and b will be evaluated before seq
returns a value. In particular, this means that b may be
evaluated before a. If you need to guarantee a specific order
of evaluation, you must use the function pseq from the
"parallel" package.