diff options
Diffstat (limited to 'lisp.c')
| -rw-r--r-- | lisp.c | 17 |
1 files changed, 10 insertions, 7 deletions
@@ -35,7 +35,7 @@ value *make_string(const char *s) { return val; } -value *NIL = NULL; +value *NIL; value *make_nil() { if (!NIL) { NIL = malloc(sizeof(value)); @@ -94,12 +94,11 @@ value *reverse(value *list) { return reversed; } -void *println_value(value *val){ +void println_value(value *val){ print_value(val); printf("\n"); } -void *print_value(value *val){ - char *str; +void print_value(value *val){ switch (val->type) { case VT_INT: printf("%d", val->as.i); @@ -159,8 +158,6 @@ void *print_value(value *val){ default: printf("<unknown>\n"); } - - return val; } env *env_create(env *parent) { @@ -173,6 +170,12 @@ env *env_create(env *parent) { } env *env_define(env *e, const char *sym, value *val) { + //if symbol has been found, redefine + if (e->symbol && !strcmp(e->symbol, sym)) { + e->value = val; + return e; + } + //if not, find end of list and add new definition if (e->next) { return env_define(e->next, sym, val); } @@ -460,5 +463,5 @@ value *builtin_lt(env *e, value *args) { } int is_integer(double x) { - return floor(x) == x && isfinite(x); + return floor(x) == x && isfinite(x); } |