This library provides writef/1 and friends. These predicates originate
from Edinburgh C-Prolog and and provided for compatibility purposes. New
code should use format/1, format/2 and friends, which are currently
supported by more Prolog implementations.
The writef-family of predicates conflicts with the modern
character-esacapes flag about the interpretation of \-sequences.
This can be avoided by
- Disable character escapes (not recommended unless one wants to
run really outdated code unmodified).
- Double the \ for conflicting interpretations
- Use ISO compliant alternatives for conflicting interpretations
- copyright
- - Copied from Edinburgh C-Prolog. Original version by Byrd,
changed many times since.
- writef(+Format) is det
- writef(+Format, +Arguments) is det
- Formatted write to the
current_output
. Format is a format
specifier. Some escape sequences require arguments that must be
provided in the list Arguments. There are two types of escape
sequences: special characters start with \
and include
arguments start with %
. The special character sequences are:
\n | Output a newline character |
\l | Output a line separator (same as \n ) |
\r | Output a carriage-return character (ASCII 13) |
\r | Output a TAB character (ASCII 9) |
\\ | Output \ |
\% | Output % |
\nnn | Output character <nnn>. <nnn> is a 1-3 decimal number |
Escape sequences to include arguments from Arguments. Each time
a %-escape sequence is found in Format the next argument from
Arguments is formatted according to the specification.
%t | print/1 the next item (mnemonic: term) |
%w | write/1 the next item |
%q | writeq/1 the next item |
%d | display/1 the next item |
%n | Put the next item as a character |
%r | Write the next item N times where N is the second item (an integer) |
%s | Write the next item as a String (so it must be a list of characters) |
%f | Perform a ttyflush/0 (no items used) |
%Nc | Write the next item Centered in N columns. |
%Nl | Write the next item Left justified in N columns. |
%Nr | Write the next item Right justified in N columns. |
- deprecated
- - New code should use format/1, format/2, etc.
- swritef(-String, +Format) is det
- swritef(-String, +Format, +Arguments) is det
- Use writef/1 or writef/2 and write the result to a string.
Note that this is a string in the sense of string_codes/2,
not a list of
character(-code)
s.
- deprecated
- - . See format/2,3 and/or with_output_to/2.
Re-exported predicates
The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.
- writef(+Format) is det
- writef(+Format, +Arguments) is det
- Formatted write to the
current_output
. Format is a format
specifier. Some escape sequences require arguments that must be
provided in the list Arguments. There are two types of escape
sequences: special characters start with \
and include
arguments start with %
. The special character sequences are:
\n | Output a newline character |
\l | Output a line separator (same as \n ) |
\r | Output a carriage-return character (ASCII 13) |
\r | Output a TAB character (ASCII 9) |
\\ | Output \ |
\% | Output % |
\nnn | Output character <nnn>. <nnn> is a 1-3 decimal number |
Escape sequences to include arguments from Arguments. Each time
a %-escape sequence is found in Format the next argument from
Arguments is formatted according to the specification.
%t | print/1 the next item (mnemonic: term) |
%w | write/1 the next item |
%q | writeq/1 the next item |
%d | display/1 the next item |
%n | Put the next item as a character |
%r | Write the next item N times where N is the second item (an integer) |
%s | Write the next item as a String (so it must be a list of characters) |
%f | Perform a ttyflush/0 (no items used) |
%Nc | Write the next item Centered in N columns. |
%Nl | Write the next item Left justified in N columns. |
%Nr | Write the next item Right justified in N columns. |
- deprecated
- - New code should use format/1, format/2, etc.
- swritef(-String, +Format) is det
- swritef(-String, +Format, +Arguments) is det
- Use writef/1 or writef/2 and write the result to a string.
Note that this is a string in the sense of string_codes/2,
not a list of
character(-code)
s.
- deprecated
- - . See format/2,3 and/or with_output_to/2.