Pervasives 'general output functions'

Pervasives 'general output functions'

[Diego Olivier Fernandez Pons]

    Bonjour,

I would like a Caml program to output some information to an output
channel and according to my needs this channel be redirected to
- a (human readable) file
- the standard output
- a black hole

The "general output functions" section of Pervasives seem to be what I
need but it hasn't the same signature than "Output functions on
standard output"

print_char    ->  output_char
print_string  ->  output_string
print_int     ->  ?
print_float   ->  ?
print_endline ->  ?
print_newline ->  ?

I suspect I could just compose with string_of_X functions to obtain
the same result. There is also an awful [fprintf] function inherided
from C but I am still trying to understand the doc (never understood
C's either).

Why haven't the equivalent functions been added to the standard lib to
allow a drop in replacement ?


        Diego Olivier

Re: [Caml-list] Pervasives 'general output functions'

[Nicolas Cannasse]

>     Bonjour,
>
> I would like a Caml program to output some information to an output
> channel and according to my needs this channel be redirected to
> - a (human readable) file
> - the standard output
> - a black hole
>
> The "general output functions" section of Pervasives seem to be what I
> need but it hasn't the same signature than "Output functions on
> standard output"

Generic IO from ExtLib are dealing with this problem, and have a printf
functionnality.
They also have useful functions such as  write_i16 / write_ui32 .... (in low
and big endian) when dealing with C binary files.

> I suspect I could just compose with string_of_X functions to obtain
> the same result. There is also an awful [fprintf] function inherided
> from C but I am still trying to understand the doc (never understood
> C's either).

printf "%d %f %s %c"  33 1.234 "hello" 'x'

> Why haven't the equivalent functions been added to the standard lib to
> allow a drop in replacement ?

Maybe because printf allows you to specify precision for int/floats as well
as newlines ?

Nicolas