Experts, I would like to understand what exactly is meant by "tuple" in the perse of PCCARDS and PCMCIA standards?I googled in net,but has not hit a right target.Can anyone explain me about this?
Advanced thanks for all your replys , Regards, s.subbarayan
It's a term used to describe a small block of bytes - I've never seen it used outside the PCMCIA spec. though - I don't know if they made it up or it was already in (obscure) existence
'Record' or 'Structure' would probably be the closest conventional word.
tuple
In functional languages, a data object containing two or more components. Also known as a product type or pair, triple, quad, etc. Tuples of different sizes have different types, in contrast to lists where the type is independent of the length. The components of a tuple may be of different types whereas all elements of a list have the same type. Examples of tuples in Haskell notation are (1,2), ("Tuple",True), (w,(x,y),z). The degenerate tuple with zero components, written (), is known as the unit type since it has only one possible value which is also written ().
The implementation of tuples in a language may be either "lifted" or not. If tuples are lifted then (bottom,bottom) /=3D bottom and the evaluation of a tuple may fail to terminate. E=2Eg. in Haskell:
f (x,y) =3D 1 --> f bottom =3D bottom f (bottom,bottom) =3D 1
With lifted tuples, a tuple pattern is refutable. Thus in Haskell, pattern matching on tuples is the same as pattern matching on types with multiple constructors (algebraic data types) - the expression being matched is evaluated as far as the top level constructor, even though, in the case of tuples, there is only one possible constructor for a given type.
If tuples are unlifted then (bottom, bottom) =3D bottom and evaluation of a tuple will never fail to terminate though any of the components may. E.g. in Miranda:
f (x,y) =3D 1 --> f bottom =3D 1 f (bottom,bottom) =3D 1
Thus in Miranda, any object whose type is compatible with a tuple pattern is assumed to match at the top level without evaluation - it is an irrefutable pattern. This also applies to user defined data types with only one constructor. In Haskell, patterns can be made irrefutable by adding a "~" as in
f ~(x,y) =3D 1.
If tuple constructor functions were strict in all their arguments then (bottom,x) =3D (x,bottom) =3D bottom for any x so matching a refutable pattern would fail to terminate if any component was bottom.
Source: The Free On-line Dictionary of Computing, =A9 1993-2005 Denis Howe
The word tuple in PCCard standard refers to the element of the Card Information Structure (or CIS a.k.a. Metaformat). Tuple is a variable-length record consisting of the tuple code, tuple' link (serves as a length field) and tuple' body. CIS is stored in the attribute memory of the 16-bit PCCARD (R2-cards in M$speak). 32-bit PC-cards known as CARDBUS also could have CIS but it would be of little utility because a regular PCI configuration space already provides a sufficient info for plug&play. Further information available in the official PCCARD standard. You can order the standard from
I remember from linear algebra, the prof. was always going on about 'n-tuples' which were vectors of length 'n' IIRC. I thought that was unecessary obfuscation, but this sounds like real gobbledygook.
Bob
A tuple is a set of values that are associated with each other and passed around together as a group. Like a "struct" in C.
Odd. I googled for tuple definition, and found lots of definitions.
-- Grant Edwards grante@visi.com
It's a common term in computer science an math.
Yup.
-- Grant Edwards grante@visi.com
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.