List stuff

src/types.h

@@ -19,6 +19,10 @@ typedef enum GroundArgType {
     VALUE, VALREF, DIRREF, LINEREF, LABEL, FNREF, TYPEREF
 } GroundArgType;
 
+typedef enum ListAccessStatus {
+    LIST_OKAY, LIST_OUT_OF_BOUNDS, LIST_FIXME
+} ListAccessStatus;
+
 struct GroundValue;
 
 struct List;
@@ -43,14 +47,25 @@ typedef struct GroundValue {
 } GroundValue;
 
 /*
- * Currently unused. Max, implement this sometime soon.
+ * Custom data type that stores Ground values.
+ * Associated functions:
+ *    createList(), appendToList(), getListAt(), setListAt()
  */
 typedef struct List {
     size_t size;
-    size_t capacity;
     GroundValue* values;
 } List;
 
+/*
+ * Indicates status when accessing a list.
+ * Associated functions:
+ *    getListAt()
+ */
+typedef struct ListAccess {
+    ListAccessStatus status;
+    GroundValue* value;
+} ListAccess;
+
 /*
  * Stores arguments for the GroundInstruction struct.
  * Associated functions:
@@ -125,4 +140,17 @@ void addArgToInstruction(GroundInstruction* gi, GroundArg arg);
 // Prints out a GroundInstruction.
 void printGroundInstruction(GroundInstruction* gi);
 
+// Creates a Ground list
+List createList();
+
+// Add item (value) to List (list)
+void appendToList(List* list, GroundValue value);
+
+// Gets item at index (idx) from list (list). If there is an error, it
+// will be indicated in the status field.
+ListAccess getListAt(List* list, int idx);
+
+// Sets an item in list (list) at index (idx) to GroundValue (value).
+ListAccessStatus setListAt(List* list, int idx, GroundValue value);
+
 #endif