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retrieve the character code of the character at the current stream position.
peek_code(?Char)
peek_code(+Stream, ?Code)
peek_code/1 retrieves the character code of the character at the stream position of the current input stream.
peek_char/2 retrieves the character code of the character at the stream position of the stream Stream.
The stream position will not be altered by these predicates.
peek_code retrieves the character code of the character at the current stream position and unifies it with Code. If the stream position is behind the end of the inputstream, Code will be unified with -1.
Arguments
Stream text input stream Code integer (unicode or -1)
Examples
Assume the content of a stream S is abcdefg and the stream position is at the 1st character.
| peek_code(0'a). | Succeeds. The stream position will not be altered. |
| peek_char(C). | Succeeds with substitution(C<-0'a). The stream position will not be altered. |
Standard
These predicates are part of the ISO-Prolog Standard.
See also
get_char/1/2, get_code/1/2, peek_char/1/2, put_char/1/2, put_code/1/2, nl/0/1, set_input/1, current_input/1.
| document: http://www.ifcomputer.co.jp/MINERVA/Manual/Reference/Predicates/char_io/peek_code/print_en.html published 2008/11/17 update 2001/8/28 (c) 1996-2006 IF Computer Japan | ||||||||
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