mes/string.c

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/* -*-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) ///((args . n))
{
char buf[STRING_MAX] = "";
char *p = buf;
while (x != &scm_nil)
{
scm *s = car (x);
assert (s->type == CHAR);
*p++ = s->value;
x = cdr (x);
}
return make_string (buf);
}
scm *
string_append (scm *x) ///((args . n))
{
char buf[STRING_MAX] = "";
while (x != &scm_nil)
{
scm *s = car (x);
assert (s->type == STRING);
strcat (buf, s->name);
x = cdr (x);
}
return make_string (buf);
}
scm *
list_to_string (scm *x)
{
char buf[STRING_MAX] = "";
char *p = buf;
while (x != &scm_nil)
{
scm *s = car (x);
assert (s->type == CHAR);
*p++ = s->value;
x = cdr (x);
}
*p = 0;
return make_string (buf);
}
scm *
string_length (scm *x)
{
assert (x->type == STRING);
return make_number (strlen (x->name));
}
scm *
string_ref (scm *x, scm *k)
{
assert (x->type == STRING);
assert (k->type == NUMBER);
return make_char (x->name[k->value]);
}
scm *
substring (scm *x) ///((args . n))
{
assert (x->type == PAIR);
assert (x->car->type == STRING);
char const *s = x->car->name;
assert (x->cdr->car->type == NUMBER);
int start = x->cdr->car->value;
int end = strlen (s);
if (x->cdr->cdr->type == PAIR) {
assert (x->cdr->cdr->car->type == NUMBER);
assert (x->cdr->cdr->car->value <= end);
end = x->cdr->cdr->car->value;
}
char buf[STRING_MAX];
strncpy (buf, s+start, end - start);
buf[end-start] = 0;
return make_string (buf);
}
scm *
number_to_string (scm *x)
{
assert (x->type == NUMBER);
char buf[STRING_MAX];
sprintf (buf,"%d", x->value);
return make_string (buf);
}
scm *
string_to_symbol (scm *x)
{
assert (x->type == STRING);
return make_symbol (x->name);
}
scm *
symbol_to_string (scm *x)
{
assert (x->type == SYMBOL);
return make_string (x->name);
}