code.kerkeslager.com Git - fur/blob - templates/environment.c

   1 struct _EnvironmentNode;
   2 typedef struct _EnvironmentNode _EnvironmentNode;
   3 struct _EnvironmentNode {
   4   const char* symbol;
   5   Object value;
   6   _EnvironmentNode* next;
   7 };
   8
   9 struct Environment;
  10 typedef struct Environment Environment;
  11 struct Environment {
  12   _EnvironmentNode* top;
  13 };
  14
  15 struct Environment_get_Result;
  16 typedef struct Environment_get_Result Environment_get_Result;
  17 struct Environment_get_Result {
  18   bool found;
  19   Object result;
  20 };
  21
  22 void Environment_initialize(Environment* self) {
  23   self->top = NULL;
  24 }
  25
  26 void Environment_deinitialize(Environment* self) {
  27   while(self->top != NULL) {
  28     _EnvironmentNode* en = self->top;
  29     self->top = en->next;
  30     Object_deinitialize(&(en->value));
  31     free(en);
  32   }
  33 }
  34
  35 Environment* Environment_construct() {
  36   Environment* result = malloc(sizeof(Environment));
  37   Environment_initialize(result);
  38   return result;
  39 }
  40
  41 void Environment_destruct(Environment* self) {
  42   Environment_deinitialize(self);
  43   free(self);
  44 }
  45
  46 Environment_get_Result Environment_get(Environment* self, char* symbol) {
  47   for(_EnvironmentNode* current = self->top; current != NULL; current = current->next) {
  48     if(strcmp(current->symbol, symbol) == 0) {
  49       return (Environment_get_Result) { true, current->value };
  50     }
  51   }
  52   return (Environment_get_Result) { false, BUILTIN_NIL };
  53 }
  54
  55 void Environment_set(Environment* self, char* symbol, Object value) {
  56   assert(!(Environment_get(self, symbol).found));
  57
  58   _EnvironmentNode* en = malloc(sizeof(_EnvironmentNode));
  59   en->symbol = symbol;
  60   en->value = value;
  61   en->next = self->top;
  62   self->top = en;
  63 }