Variables and basic math

[fur] / templates / environment.c

diff --git a/templates/environment.c b/templates/environment.c
new file mode 100644 (file)
index 0000000..4ed5302
--- /dev/null
+++ b/templates/environment.c
@@ -0,0 +1,63 @@
+struct _EnvironmentNode;
+typedef struct _EnvironmentNode _EnvironmentNode;
+struct _EnvironmentNode {
+  const char* symbol;
+  Object value;
+  _EnvironmentNode* next;
+};
+
+struct Environment;
+typedef struct Environment Environment;
+struct Environment {
+  _EnvironmentNode* top;
+};
+
+struct Environment_get_Result;
+typedef struct Environment_get_Result Environment_get_Result;
+struct Environment_get_Result {
+  bool found;
+  Object result;
+};
+
+void Environment_initialize(Environment* self) {
+  self->top = NULL;
+}
+
+void Environment_deinitialize(Environment* self) {
+  while(self->top != NULL) {
+    _EnvironmentNode* en = self->top;
+    self->top = en->next;
+    Object_deinitialize(&(en->value));
+    free(en);
+  }
+}
+
+Environment* Environment_construct() {
+  Environment* result = malloc(sizeof(Environment));
+  Environment_initialize(result);
+  return result;
+}
+
+void Environment_destruct(Environment* self) {
+  Environment_deinitialize(self);
+  free(self);
+}
+
+Environment_get_Result Environment_get(Environment* self, char* symbol) {
+  for(_EnvironmentNode* current = self->top; current != NULL; current = current->next) {
+    if(strcmp(current->symbol, symbol) == 0) {
+      return (Environment_get_Result) { true, current->value };
+    }
+  }
+  return (Environment_get_Result) { false, BUILTIN_NIL };
+}
+
+void Environment_set(Environment* self, char* symbol, Object value) {
+  assert(!(Environment_get(self, symbol).found));
+
+  _EnvironmentNode* en = malloc(sizeof(_EnvironmentNode));
+  en->symbol = symbol;
+  en->value = value;
+  en->next = self->top;
+  self->top = en;
+}