Add struct field access

README.md

@@ -82,7 +82,7 @@ build
         - [x] Return values (type checked)
         - [x] Arguments for functions
         - [x] Jumping within functions
-    - [ ] Custom data structures
+    - [x] Custom data structures
     - [ ] Working with external libraries
 
 ## Debugger

src/interpreter.c

@@ -2028,6 +2028,77 @@ GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scop
             break;
         }
 
+        /*
+         * OBJECTS
+         * Allows manipulation of Ground objects.
+         */
+        // getfield $obj &field &result
+        case GETFIELD: {
+            if (in->args.length < 3) {
+                runtimeError(TOO_FEW_ARGS, "Expecting 3 args", in, currentInstruction);
+            }
+            if (in->args.length > 3) {
+                runtimeError(TOO_MANY_ARGS, "Expecting 3 args", in, currentInstruction);
+            }
+            if (in->args.args[0].type != VALUE) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting an Object for arg 1", in, currentInstruction);
+            }
+            if (in->args.args[0].value.value.type != CUSTOM) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting an Object for arg 1", in, currentInstruction);
+            }
+            if (in->args.args[1].type != DIRREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef for arg 2", in, currentInstruction);
+            }
+            if (in->args.args[2].type != DIRREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef for arg 3", in, currentInstruction);
+            }
+
+            GroundObjectField* field = findField(*in->args.args[0].value.value.data.customVal, in->args.args[1].value.refName);
+            if (field == NULL) {
+                runtimeError(UNKNOWN_VARIABLE, "Struct does not contain that field", in, currentInstruction);
+            }
+            addVariable(scope->variables, in->args.args[2].value.refName, field->value);
+            
+            break;
+        }
+        // setfield &obj &field $value
+        case SETFIELD: {
+            if (in->args.length < 3) {
+                runtimeError(TOO_FEW_ARGS, "Expecting 3 args", in, currentInstruction);
+            }
+            if (in->args.length > 3) {
+                runtimeError(TOO_MANY_ARGS, "Expecting 3 args", in, currentInstruction);
+            }
+            if (in->args.args[0].type != DIRREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef to an Object for arg 1", in, currentInstruction);
+            }
+            if (in->args.args[1].type != DIRREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef for arg 2", in, currentInstruction);
+            }
+            if (in->args.args[2].type != VALUE) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a Value for arg 3", in, currentInstruction);
+            }
+
+            GroundVariable* var = findVariable(*scope->variables, in->args.args[0].value.refName);
+            if (var == NULL) {
+                runtimeError(UNKNOWN_VARIABLE, "Could not find that object", in, currentInstruction);
+            }
+            if (var->value.type != CUSTOM) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef to an Object for arg 1", in, currentInstruction);
+            }
+
+            GroundObjectField* field = findField(*var->value.data.customVal, in->args.args[1].value.refName);
+            if (field == NULL) {
+                runtimeError(UNKNOWN_VARIABLE, "Struct does not contain that field", in, currentInstruction);
+            }
+            if (field->value.type != in->args.args[2].value.value.type) {
+                runtimeError(ARG_TYPE_MISMATCH, "Field type and provided type do not match", in, currentInstruction);
+            }
+
+            field->value = copyGroundValue(&in->args.args[2].value.value);
+            break;
+        }
+
         case DROP: {
             if (in->args.length < 1) {
                 runtimeError(TOO_FEW_ARGS, "Expecting 1 arg", in, currentInstruction);

src/parser.c

@@ -168,6 +168,8 @@ static GroundInstType getInstructionType(const char* inst) {
     if (strcmp(inst, "struct") == 0) return STRUCT;
     if (strcmp(inst, "endstruct") == 0) return ENDSTRUCT;
     if (strcmp(inst, "init") == 0) return INIT;
+    if (strcmp(inst, "getfield") == 0) return GETFIELD;
+    if (strcmp(inst, "setfield") == 0) return SETFIELD;
     if (strcmp(inst, "use") == 0) return USE;
     if (strcmp(inst, "extern") == 0) return EXTERN;
     if (strcmp(inst, "drop") == 0) return DROP;

src/types.h

@@ -9,7 +9,7 @@
 #include "include/uthash.h"
 
 typedef enum GroundInstType {
-    IF, JUMP, END, INPUT, PRINT, PRINTLN, SET, GETTYPE, EXISTS, SETLIST, SETLISTAT, GETLISTAT, GETLISTSIZE, LISTAPPEND, GETSTRSIZE, GETSTRCHARAT, ADD, SUBTRACT, MULTIPLY, DIVIDE, EQUAL, INEQUAL, NOT, GREATER, LESSER, STOI, STOD, TOSTRING, FUN, RETURN, ENDFUN, PUSHARG, CALL, STRUCT, ENDSTRUCT, INIT, USE, EXTERN, CREATELABEL, PAUSE, DROP, ERRORCMD
+    IF, JUMP, END, INPUT, PRINT, PRINTLN, SET, GETTYPE, EXISTS, SETLIST, SETLISTAT, GETLISTAT, GETLISTSIZE, LISTAPPEND, GETSTRSIZE, GETSTRCHARAT, ADD, SUBTRACT, MULTIPLY, DIVIDE, EQUAL, INEQUAL, NOT, GREATER, LESSER, STOI, STOD, TOSTRING, FUN, RETURN, ENDFUN, PUSHARG, CALL, STRUCT, ENDSTRUCT, INIT, GETFIELD, SETFIELD, USE, EXTERN, CREATELABEL, PAUSE, DROP, ERRORCMD
 } GroundInstType;
 
 typedef enum GroundValueType {

tests/struct.grnd

@@ -0,0 +1,17 @@
+struct -point
+
+    init &x -int
+    init &y -int
+
+endstruct
+
+init &mypoint -point
+
+setfield &mypoint &x 53
+setfield &mypoint &y 32
+
+getfield $mypoint &x &value
+println $value
+
+getfield $mypoint &y &value
+println $value