<s>
In	O
functional	B-Language
programming	I-Language
,	O
a	O
result	B-Application
type	I-Application
is	O
a	O
Monadic	O
type	O
holding	O
a	O
returned	O
value	O
or	O
an	O
error	O
code	O
.	O
</s>
<s>
They	O
provide	O
an	O
elegant	O
way	O
of	O
handling	O
errors	O
,	O
without	O
resorting	O
to	O
exception	B-General_Concept
handling	I-General_Concept
;	O
when	O
a	O
function	O
that	O
may	O
fail	O
returns	O
a	O
result	B-Application
type	I-Application
,	O
the	O
programmer	O
is	O
forced	O
to	O
consider	O
success	O
or	O
failure	O
paths	O
,	O
before	O
getting	O
access	O
to	O
the	O
expected	O
result	O
;	O
this	O
eliminates	O
the	O
possibility	O
of	O
an	O
erroneous	O
programmer	O
assumption	O
.	O
</s>
<s>
In	O
Elm	B-Language
,	O
it	O
is	O
defined	O
by	O
the	O
standard	O
library	O
as	O
.	O
</s>
<s>
In	O
Haskell	B-Language
,	O
by	O
convention	O
the	O
type	O
is	O
used	O
for	O
this	O
purpose	O
,	O
which	O
is	O
defined	O
by	O
the	O
standard	O
library	O
as	O
.	O
</s>
<s>
In	O
OCaml	B-Language
,	O
it	O
is	O
defined	O
by	O
the	O
standard	O
library	O
as	O
.	O
</s>
<s>
In	O
Rust	B-Application
,	O
it	O
is	O
defined	O
by	O
the	O
standard	O
library	O
as	O
.	O
</s>
<s>
In	O
Scala	B-Application
,	O
the	O
standard	O
library	O
also	O
defines	O
an	O
type	O
,	O
however	O
Scala	B-Application
also	O
has	O
more	O
conventional	O
exception	B-General_Concept
handling	I-General_Concept
.	O
</s>
<s>
In	O
Swift	B-Application
,	O
it	O
is	O
defined	O
by	O
the	O
standard	O
library	O
as	O
.	O
</s>
