| slovo | definícia |
refutable
(encz) | refutable,vyvratitelný adj: Zdeněk Brož |
Refutable
(gcide) | Refutable \Re*fut"a*ble\ (r?*f?t"?*b'l;277), a. [Cf. F.
r['e]futable.]
Admitting of being refuted or disproved; capable of being
proved false or erroneous.
[1913 Webster] |
refutable
(wn) | refutable
adj 1: able to be refuted [syn: questionable, refutable,
confutable, confutative] |
refutable
(foldoc) | refutable
In lazy functional languages, a refutable pattern
is one which may fail to match. An expression being matched
against a refutable pattern is first evaluated to {head normal
form} (which may fail to terminate) and then the top-level
constructor of the result is compared with that of the pattern.
If they are the same then any arguments are matched against the
pattern's arguments otherwise the match fails.
An irrefutable pattern is one which always matches. An attempt to
evaluate any variable in the pattern forces the pattern to be
matched as though it were refutable which may fail to match
(resulting in an error) or fail to terminate.
Patterns in Haskell are normally refutable but may be made
irrefutable by prefixing them with a tilde (~). For example,
(\ (x,y) -> 1) undefined ==> undefined
(\ ~(x,y) -> 1) undefined ==> 1
Patterns in Miranda are refutable, except for tuples which are
irrefutable. Thus
g [x] = 2
g undefined ==> undefined
f (x,y) = 1
f undefined ==> 1
Pattern bindings in local definitions are irrefutable in both
languages:
h = 1 where [x] = undefined ==> 1
Irrefutable patterns can be used to simulate unlifted products
because they effectively ignore the top-level constructor of the
expression being matched and consider only its components.
(2013-11-03)
|
| | podobné slovo | definícia |
irrefutable
(encz) | irrefutable,nevyvratitelný adj: Zdeněk Brož |
refutable
(encz) | refutable,vyvratitelný adj: Zdeněk Brož |
Irrefutable
(gcide) | Irrefutable \Ir`re*fut"a*ble\ (?; 277), a. [L. irrefutabilis:
cf. F. irr['e]futable. See Refute.]
Incapable of being refuted or disproved; indisputable. --
Ir`re*fut"a*ble*ness, n. -- Ir`re*fut"a*bly, adv.
[1913 Webster] |
Irrefutableness
(gcide) | Irrefutable \Ir`re*fut"a*ble\ (?; 277), a. [L. irrefutabilis:
cf. F. irr['e]futable. See Refute.]
Incapable of being refuted or disproved; indisputable. --
Ir`re*fut"a*ble*ness, n. -- Ir`re*fut"a*bly, adv.
[1913 Webster] |
irrefutable
(wn) | irrefutable
adj 1: impossible to deny or disprove; "incontrovertible proof
of the defendant's innocence"; "proof positive"; "an
irrefutable argument" [syn: incontrovertible,
irrefutable, positive] |
refutable
(wn) | refutable
adj 1: able to be refuted [syn: questionable, refutable,
confutable, confutative] |
irrefutable
(foldoc) | irrefutable
The opposite of refutable.
|
refutable
(foldoc) | refutable
In lazy functional languages, a refutable pattern
is one which may fail to match. An expression being matched
against a refutable pattern is first evaluated to {head normal
form} (which may fail to terminate) and then the top-level
constructor of the result is compared with that of the pattern.
If they are the same then any arguments are matched against the
pattern's arguments otherwise the match fails.
An irrefutable pattern is one which always matches. An attempt to
evaluate any variable in the pattern forces the pattern to be
matched as though it were refutable which may fail to match
(resulting in an error) or fail to terminate.
Patterns in Haskell are normally refutable but may be made
irrefutable by prefixing them with a tilde (~). For example,
(\ (x,y) -> 1) undefined ==> undefined
(\ ~(x,y) -> 1) undefined ==> 1
Patterns in Miranda are refutable, except for tuples which are
irrefutable. Thus
g [x] = 2
g undefined ==> undefined
f (x,y) = 1
f undefined ==> 1
Pattern bindings in local definitions are irrefutable in both
languages:
h = 1 where [x] = undefined ==> 1
Irrefutable patterns can be used to simulate unlifted products
because they effectively ignore the top-level constructor of the
expression being matched and consider only its components.
(2013-11-03)
|
|