mes/string.c
Jan Nieuwenhuizen 46a617f16e core: Support keywords.
* display.c (display): Handle keyword.
* mes.c (type_t): Add KEYWORD.
  (eq_p): Handle it.
  (make_keyword): New function.
* reader.c (lookup): Use it.
* type.c (keyword_p): New function.
* NEWS: Update.
2016-12-16 23:30:33 +01:00

127 lines
2.7 KiB
C

/* -*-comment-start: "//";comment-end:""-*-
* Mes --- Maxwell Equations of Software
* Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of Mes.
*
* Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* Mes is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Mes. If not, see <http://www.gnu.org/licenses/>.
*/
SCM
string (SCM x) ///((arity . n))
{
return make_string (x);
}
SCM
string_append (SCM x) ///((arity . n))
{
SCM p = cell_nil;
while (x != cell_nil)
{
SCM s = car (x);
assert (TYPE (s) == STRING);
p = append2 (p, STRING (s));
x = cdr (x);
}
return make_string (p);
}
SCM
list_to_string (SCM x)
{
return make_string (x);
}
SCM
string_length (SCM x)
{
assert (TYPE (x) == STRING);
return make_number (VALUE (length (STRING (x))));
}
SCM
string_ref (SCM x, SCM k)
{
assert (TYPE (x) == STRING);
assert (TYPE (k) == NUMBER);
VALUE (tmp_num) = VALUE (k);
return make_char (VALUE (list_ref (STRING (x), tmp_num)));
}
SCM
substring (SCM x) ///((arity . n))
{
assert (TYPE (x) == PAIR);
assert (TYPE (car (x)) == STRING);
SCM s = STRING (car (x));
assert (TYPE (cadr (x)) == NUMBER);
int start = VALUE (cadr (x));
int end = VALUE (length (s));
if (TYPE (cddr (x)) == PAIR) {
assert (TYPE (caddr (x)) == NUMBER);
assert (VALUE (caddr (x)) <= end);
end = VALUE (caddr (x));
}
int n = end - start;
while (start--) s = cdr (s);
SCM p = cell_nil;
while (n-- && s != cell_nil) {
p = append2 (p, cons (make_char (VALUE (car (s))), cell_nil));
s = cdr (s);
}
return make_string (p);
}
SCM
number_to_string (SCM x)
{
assert (TYPE (x) == NUMBER);
int n = VALUE (x);
SCM p = n < 0 ? cons (make_char ('-'), cell_nil) : cell_nil;
do {
p = cons (make_char (n % 10 + '0'), p);
n = n / 10;
} while (n);
return make_string (p);
}
SCM
string_to_symbol (SCM x)
{
assert (TYPE (x) == STRING);
return make_symbol (STRING (x));
}
SCM
symbol_to_string (SCM x)
{
assert (TYPE (x) == SYMBOL);
return make_string (STRING (x));
}
SCM
keyword_to_symbol (SCM x)
{
assert (TYPE (x) == KEYWORD);
return make_symbol (STRING (x));
}
SCM
symbol_to_keyword (SCM x)
{
assert (TYPE (x) == SYMBOL);
return make_keyword (STRING (x));
}