Portability | non-portable (GHC Extensions) |
---|---|
Stability | internal |
Maintainer | cvs-ghc@haskell.org |
GHC type definitions. Use GHC.Exts from the base package instead of importing this module directly.
Documentation
The character type Char
is an enumeration whose values represent
Unicode (or equivalently ISO/IEC 10646) characters
(see http://www.unicode.org/ for details).
This set extends the ISO 8859-1 (Latin-1) character set
(the first 256 charachers), which is itself an extension of the ASCII
character set (the first 128 characters).
A character literal in Haskell has type Char
.
To convert a Char
to or from the corresponding Int
value defined
by Unicode, use Prelude.toEnum
and Prelude.fromEnum
from the
Prelude.Enum
class respectively (or equivalently ord
and chr
).
A fixed-precision integer type with at least the range [-2^29 .. 2^29-1]
.
The exact range for a given implementation can be determined by using
Prelude.minBound
and Prelude.maxBound
from the Prelude.Bounded
class.
Single-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE single-precision type.
Double-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE double-precision type.
A value of type
is a computation which, when performed,
does some I/O before returning a value of type IO
aa
.
There is really only one way to "perform" an I/O action: bind it to
Main.main
in your program. When your program is run, the I/O will
be performed. It isn't possible to perform I/O from an arbitrary
function, unless that function is itself in the IO
monad and called
at some point, directly or indirectly, from Main.main
.
IO
is a monad, so IO
actions can be combined using either the do-notation
or the >>
and >>=
operations from the Monad
class.