Finish conditional compilation of operators
[fur] / templates / program.c
index d027c52..897ca5e 100644 (file)
@@ -1,3 +1,6 @@
+#include <assert.h>
+#include <inttypes.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <{{standard_library}}>
 {% endfor %}
 
-struct String;
-typedef struct String String;
-struct Runtime;
-typedef struct Runtime Runtime;
+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 String
+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
 {
-  size_t length;
-  char* characters;
+  BOOLEAN,
+  CLOSURE,
+  INTEGER,
+  STRING
 };
 
-struct Runtime
+union Instance
 {
-  size_t permanentStringsLength;
-  size_t permanentStringsAllocated;
-  String** permanentStrings;
+  bool boolean;
+  Object (*closure)(Environment*, size_t, Object*);
+  int32_t integer;
+  const char* string;
 };
 
-Runtime* Runtime_construct()
+struct Object
 {
-  Runtime* result = malloc(sizeof(Runtime));
-  result->permanentStringsLength = 0;
-  result->permanentStringsAllocated = 0;
-  result->permanentStrings = NULL;
-  return result;
-}
+  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
+{
+  size_t referenceCount;
+  Environment* parent;
+  EnvironmentNode* root;
+};
 
-void Runtime_destruct(Runtime* self)
+Environment* Environment_construct(Environment* parent)
 {
-  free(self->permanentStrings);
-  free(self);
+  Environment* result = malloc(sizeof(Environment));
+  result->referenceCount = 1;
+  result->parent = parent;
+  result->root = NULL;
+  return result;
 }
 
-void Runtime_addPermanentString(Runtime* self, String* string)
+void Environment_destruct(Environment* self)
 {
-  // TODO Make this function thread-safe
-  if(self->permanentStringsLength == self->permanentStringsAllocated)
+  self->referenceCount--;
+
+  if(self->referenceCount == 0)
   {
-    if(self->permanentStringsAllocated == 0)
+    EnvironmentNode* next;
+    for(EnvironmentNode* node = self->root; node != NULL; node = next)
     {
-      self->permanentStringsAllocated = 8;
+      // No objects are allocated on the heap (yet!) so we don't need to free anything else
+      next = node->next;
+      free(node);
     }
-    else
+    free(self);
+  }
+}
+
+// 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)
     {
-      self->permanentStringsAllocated = self->permanentStringsAllocated * 2;
+      return node->value;
     }
+  }
 
-    self->permanentStrings = realloc(
-      self->permanentStrings,
-      sizeof(String*) * self->permanentStringsAllocated
-    );
-
-    // TODO Handle realloc returning NULL
+  if(self->parent != NULL)
+  {
+    return Environment_get(self->parent, symbol);
   }
 
-  self->permanentStrings[self->permanentStringsLength] = string;
-  self->permanentStringsLength++;
+  // TODO Handle symbol errors
+  assert(false);
+}
+
+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;
 }
 
-String* stringLiteral(Runtime* runtime, const char* literal)
+{% for id in infix_declarations %}
+Object operator${{ id.name }}(Object left, Object right)
 {
-  String* result = malloc(sizeof(String));
-  result->length = strlen(literal);
-  result->characters = malloc(result->length);
-  memcpy(result->characters, literal, result->length);
-  Runtime_addPermanentString(runtime, result);
+  assert(left.type == {{ id.in_type.upper() }});
+  assert(right.type == {{ id.in_type.upper() }});
+
+  Object result;
+  result.type = {{ id.out_type.upper() }};
+  result.instance.{{ id.out_type.lower() }} = left.instance.{{ id.in_type.lower() }} {{ id.operator }} right.instance.{{ id.in_type.lower() }};
   return result;
 }
+{% endfor %}
+
+{% if 'pow' in builtins %}
+Object builtin$pow$implementation(Environment* parent, size_t argc, Object* args)
+{
+  assert(argc == 2);
+
+  Object base = args[0];
+  Object exponent = args[1];
+
+  assert(base.type == INTEGER);
+  assert(exponent.type == INTEGER);
+
+  Object result;
+  result.type = INTEGER;
+  result.instance.integer = pow(base.instance.integer, exponent.instance.integer);
+  return result;
+}
+
+Object builtin$pow = { CLOSURE, (Instance)builtin$pow$implementation };
+{% endif %}
 
 {% if 'print' in builtins %}
-void builtin$print(String* output)
+Object builtin$print$implementation(Environment* parent, size_t argc, Object* args)
 {
-  // Using fwrite instead of printf to handle size_t length
-  fwrite(output->characters, 1, output->length, stdout);
+  for(size_t i = 0; i < argc; i++)
+  {
+    Object output = args[i];
+    switch(output.type)
+    {
+      case BOOLEAN:
+        fputs(output.instance.boolean ? "true" : "false", stdout);
+        break;
+
+      case INTEGER:
+        printf("%" PRId32, output.instance.integer);
+        break;
+
+      case STRING:
+        // Using fwrite instead of printf to handle size_t length
+        printf("%s", output.instance.string);
+        break;
+
+      default:
+        assert(false);
+    }
+  }
+
+  // TODO Return something better
+  return FALSE;
 }
+
+Object builtin$print = { CLOSURE, (Instance)builtin$print$implementation };
 {% endif %}
 
+{% for function_definition in function_definition_list %}
+Object user${{function_definition.name}}$implementation(Environment* parent, size_t argc, Object* args)
+{
+  Environment* environment = Environment_construct(parent);
+
+  {% for statement in function_definition.statement_list[:-1] %}
+  {{ generate_statement(statement) }}
+  {% endfor %}
+
+  Object result = {{ generate_statement(function_definition.statement_list[-1]) }}
+  Environment_destruct(environment);
+  return result;
+}
+
+Object user${{function_definition.name}} = { CLOSURE, (Instance)user${{function_definition.name}}$implementation };
+{% endfor %}
+
 int main(int argc, char** argv)
 {
-  Runtime* runtime = Runtime_construct();
+  Environment* environment = Environment_construct(NULL);
+
+  // TODO Use the symbol from SYMBOL_LIST
+  {% for builtin in builtins %}
+  Environment_set(environment, "{{ builtin }}", builtin${{ builtin }});
+  {% endfor %}
 
   {% for statement in statements %}
-  {{ statement }}
+  {{ generate_statement(statement) }}
   {% endfor %}
 
-  Runtime_destruct(runtime);
+  Environment_destruct(environment);
 
   return 0;
 }