Scanf.Scanning (3)
NAME
Scanf.Scanning - no descriptionModule
Module Scanf.ScanningDocumentation
Module
Scanning
:
sig end
type in_channel
The notion of input channel for the
Scanf
module:
those channels provide all the machinery necessary to read from any source
of characters, including a
!Pervasives.in_channel
value.
A
Scanf.Scanning.in_channel
value is also called a formatted input
channel or equivalently a scanning buffer.
The type
Scanning.scanbuf
below is an alias for
Scanning.in_channel
.
Since
3.12.0
type scanbuf
=
in_channel
The type of scanning buffers. A scanning buffer is the source from which a formatted input function gets characters. The scanning buffer holds the current state of the scan, plus a function to get the next char from the input, and a token buffer to store the string matched so far.
Note: a scanning action may often require to examine one character in
advance; when this 'lookahead' character does not belong to the token
read, it is stored back in the scanning buffer and becomes the next
character yet to be read.
val stdin
:
in_channel
The standard input notion for the Scanf module. Scanning.stdin is the Scanning.in_channel formatted input channel attached to !Pervasives.stdin .
Note: in the interactive system, when input is read from
!Pervasives.stdin
, the newline character that triggers evaluation is
part of the input; thus, the scanning specifications must properly skip
this additional newline character (for instance, simply add a
'rsn'
as
the last character of the format string).
Since
3.12.0
type file_name
=
string
A convenient alias to designate a file name.
Since
4.00.0
val open_in
:
file_name -> in_channel
Scanning.open_in fname
returns a
!Scanning.in_channel
formatted input
channel for bufferized reading in text mode from file
fname
.
Note:
open_in
returns a formatted input channel that efficiently reads
characters in large chunks; in contrast,
from_channel
below returns
formatted input channels that must read one character at a time, leading
to a much slower scanning rate.
Since
3.12.0
val open_in_bin
:
file_name -> in_channel
Scanning.open_in_bin fname
returns a
!Scanning.in_channel
formatted
input channel for bufferized reading in binary mode from file
fname
.
Since
3.12.0
val close_in
:
in_channel -> unit
Closes the
!Pervasives.in_channel
associated with the given
!Scanning.in_channel
formatted input channel.
Since
3.12.0
val from_file
:
file_name -> in_channel
An alias for
!Scanning.open_in
above.
val from_file_bin
:
string -> in_channel
An alias for
!Scanning.open_in_bin
above.
val from_string
:
string -> in_channel
Scanning.from_string s
returns a
!Scanning.in_channel
formatted
input channel which reads from the given string.
Reading starts from the first character in the string.
The end-of-input condition is set when the end of the string is reached.
val from_function
:
(unit -> char) -> in_channel
Scanning.from_function f
returns a
!Scanning.in_channel
formatted
input channel with the given function as its reading method.
When scanning needs one more character, the given function is called.
When the function has no more character to provide, it must signal an
end-of-input condition by raising the exception
End_of_file
.
val from_channel
:
Pervasives.in_channel -> in_channel
Scanning.from_channel ic
returns a
!Scanning.in_channel
formatted
input channel which reads from the regular
!Pervasives.in_channel
input
channel
ic
argument.
Reading starts at current reading position of
ic
.
val end_of_input
:
in_channel -> bool
Scanning.end_of_input ic
tests the end-of-input condition of the given
!Scanning.in_channel
formatted input channel.
val beginning_of_input
:
in_channel -> bool
Scanning.beginning_of_input ic
tests the beginning of input condition
of the given
!Scanning.in_channel
formatted input channel.
val name_of_input
:
in_channel -> string
Scanning.name_of_input ic
returns the name of the character source
for the given
!Scanning.in_channel
formatted input channel.
Since
3.09.0
val stdib
:
in_channel
A deprecated alias for
!Scanning.stdin
, the scanning buffer reading from
!Pervasives.stdin
.