mem.c

   1 #include <stdlib.h>
   2 #include "lambda.h"
   3 #include "print.h"
   4
   5 void lambda_free(struct lambda *t)
   6 {
   7         if(t != NULL){
   8                 switch(t->which){
   9                 case lambda_ident:
  10                         free(t->data.identifier.ident);
  11                         break;
  12                 case lambda_abs:
  13                         free(t->data.abstraction.ident);
  14                         lambda_free(t->data.abstraction.expr);
  15                         break;
  16                 case lambda_app:
  17                         lambda_free(t->data.application.expr1);
  18                         lambda_free(t->data.application.expr2);
  19                         break;
  20                 }
  21                 free(t);
  22         }
  23 }
  24
  25 void binding_replace(struct lambda *b, struct lambda *from, struct lambda *to)
  26 {
  27         switch(b->which){
  28         case lambda_ident:
  29                 if(b->data.identifier.binding == from)
  30                         b->data.identifier.binding = to;
  31                 break;
  32         case lambda_abs:
  33                 binding_replace(b->data.abstraction.expr, from, to);
  34                 break;
  35         case lambda_app:
  36                 binding_replace(b->data.application.expr1, from, to);
  37                 binding_replace(b->data.application.expr2, from, to);
  38                 break;
  39         }
  40 }
  41
  42 struct lambda *copy(struct lambda *t)
  43 {
  44         struct lambda *c = make_lambda();
  45         c->which = t->which;
  46         switch(t->which){
  47         case lambda_ident:
  48                 c->data.identifier.ident = strdup(t->data.identifier.ident);
  49                 c->data.identifier.binding = t->data.identifier.binding;
  50                 break;
  51         case lambda_abs:
  52                 c->data.abstraction.ident = strdup(t->data.abstraction.ident);
  53                 c->data.abstraction.strict = t->data.abstraction.strict;
  54                 c->data.abstraction.expr = copy(t->data.abstraction.expr);
  55                 binding_replace(c->data.abstraction.expr, t, c);
  56                 break;
  57         case lambda_app:
  58                 c->data.application.expr1 = copy(t->data.application.expr1);
  59                 c->data.application.expr2 = copy(t->data.application.expr2);
  60                 break;
  61         }
  62         return c;
  63 }