From 166a547a74c44fca77adcec42d685c049026f096 Mon Sep 17 00:00:00 2001
From: Maxwell Jeffress <maxwelljeffress@proton.me>
Date: Sat, 6 Dec 2025 14:35:13 +1100
Subject: [PATCH] Call functions

---
 src/interpreter.c   | 53 ++++++++++++++++++++++++++++++++++++---------
 src/types.c         |  6 +++++
 src/types.h         |  4 ++++
 tests/fib.grnd      | 19 ++++++++++++++++
 tests/function.grnd |  3 ++-
 5 files changed, 74 insertions(+), 11 deletions(-)
 create mode 100644 tests/fib.grnd

diff --git a/src/interpreter.c b/src/interpreter.c
index 653833a..843d233 100644
--- a/src/interpreter.c
+++ b/src/interpreter.c
@@ -163,13 +163,14 @@ GroundValue interpretGroundProgram(GroundProgram* in, GroundScope* inScope) {
         scope.labels = &labels;
         scope.variables = &variables;
     }
-    // Preprocess all labels
+    // Preprocess all labels and functions
     for (int i = 0; i < in->size; i++) {
         if (in->instructions[i].type == CREATELABEL) {
             addLabel(scope.labels, in->instructions[i].args.args[0].value.refName, i);
         }
         if (in->instructions[i].type == FUN) {
             GroundFunction* function = createGroundFunction();
+            function->startLine = i;
             if (in->instructions[i].args.length < 1) {
                 runtimeError(TOO_FEW_ARGS, "Expecting 1 or more args", &in->instructions[i], i);
             }
@@ -203,18 +204,36 @@ GroundValue interpretGroundProgram(GroundProgram* in, GroundScope* inScope) {
                 addInstructionToProgram(&function->program, in->instructions[i]);
                 i++;
             }
-            if (&function->program.size == 0) {
-                addInstructionToProgram(&function->program, createGroundInstruction(PRINT));
-            }
             addVariable(scope.variables, functionName, createFunctionGroundValue(function));
-
         }
     }
-    while (currentInstruction < in->size) {
-        interpretGroundInstruction(in->instructions[currentInstruction], &scope);
+    for (int i = 0; i < in->size; i++) {
+        if (in->instructions[i].type == FUN) {
+            int count = 1;
+            while (count > 0) {
+                i++;
+                if (i >= in->size) {
+                    return createNoneGroundValue();
+                }
+                if (in->instructions[i].type == FUN) {
+                    count++;
+                }
+                if (in->instructions[i].type == ENDFUN) {
+                    count--;
+                }
+            }
+        }
+        int ci = currentInstruction;
+        GroundValue gv = interpretGroundInstruction(in->instructions[i], &scope);
+        if (gv.type != NONE) {
+            return gv;
+        }
+        if (ci != currentInstruction) {
+            i = currentInstruction;
+        }
         currentInstruction++;
     }
-    return createIntGroundValue(0); 
+    return createNoneGroundValue();
 }
 
 GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scope) {
@@ -1124,7 +1143,16 @@ GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scop
         *     fun, return, endfun, pusharg, call
         */
         case RETURN: {
-            break;
+            if (in->args.length < 1) {
+                runtimeError(TOO_FEW_ARGS, "Expecting 1 arg", in, currentInstruction);
+            }
+            if (in->args.length > 1) {
+                runtimeError(TOO_MANY_ARGS, "Expecting 1 arg", in, currentInstruction);
+            }
+            if (in->args.args[0].type != VALUE) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a Value for arg 1", in, currentInstruction);
+            }
+            return in->args.args[0].value.value;
         }
         case CALL: {
             if (in->args.length < 2) {
@@ -1153,13 +1181,18 @@ GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scop
                 runtimeError(UNKNOWN_VARIABLE, "Provided reference does not reference a function", in, currentInstruction);
             }
             GroundFunction* function = value->data.fnVal;
+            size_t currentCurrentInstruction = currentInstruction;
+            currentInstruction = function->startLine;
             GroundValue returnValue = interpretGroundProgram(&function->program, &newScope);
             if (returnValue.type != function->returnType) {
                 runtimeError(RETURN_TYPE_MISMATCH, "Unexpected return value type from function", in, currentInstruction);
             }
+            addVariable(scope->variables, in->args.args[1].value.refName, returnValue);
+            currentInstruction = currentCurrentInstruction;
+            break;
         }
     }
 
     freeGroundInstruction(in);
-    return createIntGroundValue(0);
+    return createNoneGroundValue();
 }
diff --git a/src/types.c b/src/types.c
index 8e6bdfd..206ff08 100644
--- a/src/types.c
+++ b/src/types.c
@@ -51,6 +51,12 @@ GroundValue createFunctionGroundValue(GroundFunction* in) {
     return gv;
 }
 
+GroundValue createNoneGroundValue() {
+    GroundValue gv;
+    gv.type = NONE;
+    return gv;
+}
+
 GroundValue copyGroundValue(const GroundValue* gv) {
     GroundValue newGv;
     newGv.type = gv->type;
diff --git a/src/types.h b/src/types.h
index 2cdd6b8..d035e43 100644
--- a/src/types.h
+++ b/src/types.h
@@ -118,6 +118,7 @@ typedef struct GroundFunction {
     size_t argSize;
     GroundValueType returnType;
     GroundProgram program;
+    size_t startLine;
 } GroundFunction;
 
 
@@ -142,6 +143,9 @@ GroundValue createListGroundValue(List in);
 // Creates a GroundValue conatining (in), with type FUNCTION.
 GroundValue createFunctionGroundValue(GroundFunction* in);
 
+// Creates a Groundvalue with type NONE.
+GroundValue createNoneGroundValue();
+
 // Creates a deep copy of a GroundValue
 GroundValue copyGroundValue(const GroundValue* gv);
 
diff --git a/tests/fib.grnd b/tests/fib.grnd
new file mode 100644
index 0000000..c1d9a60
--- /dev/null
+++ b/tests/fib.grnd
@@ -0,0 +1,19 @@
+set &a 0
+set &b 1
+set &n 92
+
+set &i 0
+@loop
+    equal $i $n &done
+    if $done %end
+    
+    add $a $b &temp
+    set &a $b
+    set &b $temp
+    
+    add $i 1 &i
+    jump %loop
+
+@end
+println "Fibonacci result:" $a
+end
diff --git a/tests/function.grnd b/tests/function.grnd
index bc98f01..2d4f46d 100644
--- a/tests/function.grnd
+++ b/tests/function.grnd
@@ -1,5 +1,6 @@
 fun !dingus -string -int &x
-
+    return "dinglefart"
 endfun
 
 call !dingus &e
+println $e