+#include <{{standard_library}}>
+{% endfor %}
+
+enum Type;
+typedef enum Type Type;
+union Instance;
+typedef union Instance Instance;
+struct Object;
+typedef struct Object Object;
+struct EnvironmentNode;
+typedef struct EnvironmentNode EnvironmentNode;
+struct Environment;
+typedef struct Environment Environment;
+struct EnvironmentPool;
+typedef struct EnvironmentPool EnvironmentPool;
+
+const char* const STRING_LITERAL_LIST[] = {
+{% for string_literal in string_literal_list %}
+ "{{ string_literal }}",
+{% endfor %}
+};
+
+const char* const SYMBOL_LIST[] = {
+{% for symbol in symbol_list %}
+ "{{ symbol }}",
+{% endfor %}
+};
+
+enum Type
+{
+ BOOLEAN,
+ CLOSURE,
+ INTEGER,
+ STRING
+};
+
+struct Closure;
+typedef struct Closure Closure;
+struct Closure
+{
+ Environment* closed;
+ Object (*call)(EnvironmentPool*, Environment*, size_t, Object*);
+};
+
+union Instance
+{
+ bool boolean;
+ Closure closure;
+ int32_t integer;
+ const char* string;
+};
+
+struct Object
+{
+ Type type;
+ Instance instance;
+};
+
+const Object TRUE = {
+ BOOLEAN,
+ { true }
+};
+
+const Object FALSE = {
+ BOOLEAN,
+ { false }
+};
+
+struct EnvironmentNode
+{
+ const char* key;
+ Object value;
+ EnvironmentNode* next;
+};
+
+struct Environment
+{
+ bool mark;
+ bool live;
+
+ Environment* parent;
+ EnvironmentNode* root;
+};
+
+void Environment_initialize(Environment* self, Environment* parent)
+{
+ self->parent = parent;
+ self->root = NULL;
+
+ // We are currently only ever initializing environments at the beginning of running functions, so
+ // for now at least we can assume that we want it to be live immediately.
+ self->live = true;
+}
+
+void Environment_deinitialize(Environment* self)
+{
+ EnvironmentNode* next;
+ for(EnvironmentNode* node = self->root; node != NULL; node = next)
+ {
+ next = node->next;
+ free(node);
+ }
+}
+
+void Environment_setLive(Environment* self, bool live)
+{
+ self->live = live;
+}
+
+void Environment_mark(Environment* self)
+{
+ if(self == NULL) return;
+ if(self->mark) return; // Prevents infinite recursion in the case of cycles
+
+ self->mark = true;
+
+ Environment_mark(self->parent);
+
+ for(EnvironmentNode* node = self->root; node != NULL; node = node->next)
+ {
+ switch(node->value.type)
+ {
+ case BOOLEAN:
+ case INTEGER:
+ case STRING:
+ break;
+
+ case CLOSURE:
+ Environment_mark(node->value.instance.closure.closed);
+ break;
+
+ default:
+ assert(false);
+ }
+ }
+}
+
+// This need not be thread safe because environments exist on one thread only
+void Environment_set(Environment* self, const char* const key, Object value)
+{
+ EnvironmentNode* node = malloc(sizeof(EnvironmentNode));
+ node->key = key;
+ node->value = value;
+ node->next = self->root;
+ self->root = node;
+}
+
+Object Environment_get(Environment* self, const char* const symbol)
+{
+ for(EnvironmentNode* node = self->root; node != NULL; node = node->next)
+ {
+ // We can compare pointers because pointers are unique in the SYMBOL_LIST
+ if(node->key == symbol)
+ {
+ return node->value;
+ }
+ }
+
+ if(self->parent != NULL)
+ {
+ return Environment_get(self->parent, symbol);
+ }
+
+ // TODO Handle symbol errors
+ assert(false);
+}
+
+# define POOL_SIZE 64
+struct EnvironmentPool
+{
+ int8_t freeIndex;
+ bool allocatedFlags[POOL_SIZE];
+ Environment environments[POOL_SIZE];
+ EnvironmentPool* overflow;
+};
+
+EnvironmentPool* EnvironmentPool_construct();
+void EnvironmentPool_initialize(EnvironmentPool*);
+void EnvironmentPool_deinitialize(EnvironmentPool*);
+void EnvironmentPool_destruct(EnvironmentPool*);
+
+EnvironmentPool* EnvironmentPool_construct()
+{
+ EnvironmentPool* result = malloc(sizeof(EnvironmentPool));
+ EnvironmentPool_initialize(result);
+ return result;
+}
+
+void EnvironmentPool_initialize(EnvironmentPool* self)
+{
+ self->overflow = NULL;
+ self->freeIndex = 0;
+
+ for(size_t i = 0; i < POOL_SIZE; i++)
+ {
+ self->allocatedFlags[i] = false;
+ self->environments[i].live = false;
+ }
+}
+
+void EnvironmentPool_deinitialize(EnvironmentPool* self)
+{
+ // We can assume if this is being called, none of the Environments are live
+ for(int8_t i = 0; i < POOL_SIZE; i++)
+ {
+ if(self->allocatedFlags[i]) Environment_deinitialize(&(self->environments[i]));
+ }
+
+ EnvironmentPool_destruct(self->overflow);
+}
+
+void EnvironmentPool_destruct(EnvironmentPool* self)
+{
+ if(self == NULL) return;
+ EnvironmentPool_deinitialize(self);
+ free(self);
+}
+
+void EnvironmentPool_GC(EnvironmentPool* self)
+{
+ // Unmark all the environments
+ for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+ {
+ for(int8_t i = 0; i < POOL_SIZE; i++)
+ {
+ current->environments[i].mark = false;
+ }
+ }
+
+ // Mark live enviroments and environments referenced by live environments
+ for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+ {
+ for(int8_t i = 0; i < POOL_SIZE; i++)
+ {
+ if(current->environments[i].live)
+ {
+ Environment_mark(&(current->environments[i]));
+ }
+ }
+ }
+
+ // TODO We never free pools until the very end--we could free a pool if two pools are empty
+ for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+ {
+ for(int8_t i = POOL_SIZE - 1; i >= 0; i--)
+ {
+ if(!current->environments[i].mark && current->allocatedFlags[i])
+ {
+ Environment_deinitialize(&(current->environments[i]));
+ current->allocatedFlags[i] = false;
+ current->freeIndex = i;
+ }
+ }
+ }
+}
+
+Environment* EnvironmentPool_allocate(EnvironmentPool* self)
+{
+ for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+ {
+ for(; current->freeIndex < POOL_SIZE; current->freeIndex++)
+ {
+ if(!current->allocatedFlags[current->freeIndex])
+ {
+ current->allocatedFlags[current->freeIndex] = true;
+ return &(current->environments[current->freeIndex]);
+ }
+ }
+ }
+
+ EnvironmentPool_GC(self);
+
+ EnvironmentPool* previous;
+ for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+ {
+ for(; current->freeIndex < POOL_SIZE; current->freeIndex++)
+ {
+ if(!current->allocatedFlags[current->freeIndex])
+ {
+ current->allocatedFlags[current->freeIndex] = true;
+ return &(current->environments[current->freeIndex]);
+ }
+ else
+ {
+ previous = current;
+ }
+ }
+ }
+
+ previous->overflow = EnvironmentPool_construct();
+ return EnvironmentPool_allocate(previous->overflow);
+}
+
+Object integerLiteral(int32_t literal)
+{
+ Object result;
+ result.type = INTEGER;
+ result.instance.integer = literal;
+ return result;
+}
+
+Object stringLiteral(const char* literal)
+{
+ Object result;
+ result.type = STRING;
+ result.instance.string = literal;
+ return result;
+}
+
+// TODO Make this conditionally added
+Object operator$negate(Object input)
+{
+ assert(input.type == INTEGER);
+
+ Object result;
+ result.type = INTEGER;
+ result.instance.integer = -input.instance.integer;
+ return result;
+}
+
+{% for id in infix_declarations %}
+Object operator${{ id.name }}(Object left, Object right)
+{
+ assert(left.type == {{ id.in_type.upper() }});
+ assert(right.type == {{ id.in_type.upper() }});
+
+ Object result;
+ result.type = {{ id.out_type.upper() }};
+ result.instance.{{ id.out_type.lower() }} = left.instance.{{ id.in_type.lower() }} {{ id.operator }} right.instance.{{ id.in_type.lower() }};
+ return result;
+}