Closures in Ground

include/groundvm.h

@@ -208,6 +208,10 @@ GroundProgram groundParseFile(const char* code);
 GroundStruct groundCreateStruct();
 void groundAddFieldToStruct(GroundStruct* gstruct, char* name, GroundValue field);
 
+// Run function returned by Ground code
+// Use argc to set count of args, accepts that amount of GroundValue's after
+GroundValue groundRunFunction(GroundFunction* function, size_t argc, ...);
+
 #ifdef __cplusplus
 }
 #endif

src/interface.c

@@ -83,9 +83,19 @@ GroundValue groundCreateValue(GroundValueType type, ...) {
             return createNoneGroundValue();
             break;
         }
-        case ERROR:
         case CUSTOM: {
+            // CUSTOM values are created from structs
+            GroundValue gv;
+            GroundStruct* gstruct = va_arg(args, GroundStruct*);
+            gv.type = CUSTOM;
+            gv.data.customVal = malloc(sizeof(GroundObject));
+            *gv.data.customVal = createObject(*gstruct);
+            gv.customType = gstruct;
+            break;
+        }
+        case ERROR: {
             // FIXME
+            return createNoneGroundValue();
             break;
         }
     }
@@ -128,3 +138,25 @@ void groundAddFieldToStruct(GroundStruct* gstruct, char* name, GroundValue field
 char* groundCompileProgram(GroundProgram* program) {
     return compileGroundProgram(program);
 }
+
+GroundValue groundRunFunction(GroundFunction* function, size_t argc, ...) {
+    va_list args;
+    va_start(args, argc);
+
+    GroundScope callScope = copyGroundScope(&function->closure);
+
+    if (argc != function->argSize) {
+        return createErrorGroundValue(createGroundError("Too few or too many arguments for function", "callError", NULL, NULL));
+    }
+
+    for (size_t i = 0; i < argc; i++) {
+        GroundValue gv = va_arg(args, GroundValue);
+        if (checkFnTypes(&gv, &function->args[i]) == false) {
+            return createErrorGroundValue(createGroundError("Mismatched argument type", "callError", NULL, NULL));
+        }
+        addVariable(callScope.variables, function->args[i].name, gv);
+    }
+    va_end(args);
+
+    return interpretGroundProgram(&function->program, &callScope);
+}

src/interpreter.c

@@ -449,6 +449,7 @@ GroundStruct parseStruct(GroundProgram* in, GroundScope* scope, size_t errorOffs
 
                 GroundFunction* function = parseFunction(&gp, errorOffset);
                 function->startLine = i;
+                function->closure = copyGroundScope(scope);
                 GroundValue gv = createFunctionGroundValue(function);
                 addFieldToStruct(&gstruct, name, gv);
                 break;
@@ -484,42 +485,6 @@ GroundValue interpretGroundProgram(GroundProgram* in, GroundScope* inScope) {
         if (in->instructions[i].type == CREATELABEL) {
             addLabel(scope.labels, in->instructions[i].args.args[0].value.refName, i);
         }
-        if (in->instructions[i].type == FUN) {
-            if (in->instructions[i].args.length < 1) {
-                runtimeError(TOO_FEW_ARGS, "Expecting 1 or more args", &in->instructions[i], i);
-            }
-            if (in->instructions[i].args.args[0].type != FNREF) {
-                runtimeError(ARG_TYPE_MISMATCH, "Expecting a FunctionRef for arg 1", &in->instructions[i], i);
-            }
-            char* name = malloc(strlen(in->instructions[i].args.args[0].value.refName) + 1);
-            strcpy(name, in->instructions[i].args.args[0].value.refName);
-
-            size_t counter = 1;
-            GroundProgram gp = createGroundProgram();
-            addInstructionToProgram(&gp, in->instructions[i]);
-            size_t errorOffset = i;
-            i++;
-            while (counter > 0) {
-                if (i >= in->size) {
-                    runtimeError(PREMATURE_EOF, "Reached end of scope before function definition ended", &in->instructions[i - 1], i - 1);
-                }
-                if (in->instructions[i].type == FUN) {
-                    counter++;
-                }
-                if (in->instructions[i].type == ENDFUN) {
-                    counter--;
-                }
-                addInstructionToProgram(&gp, in->instructions[i]);
-                i++;
-            }
-            i--;
-
-            GroundFunction* function = parseFunction(&gp, errorOffset);
-            function->startLine = i;
-            GroundValue gv = createFunctionGroundValue(function);
-
-            addVariable(scope.variables, name, gv);
-        }
         if (in->instructions[i].type == STRUCT) {
             if (in->instructions[i].args.length < 1) {
                 runtimeError(TOO_FEW_ARGS, "Expecting 1 arg", &in->instructions[i], i);
@@ -562,6 +527,44 @@ GroundValue interpretGroundProgram(GroundProgram* in, GroundScope* inScope) {
         }
     }
     for (size_t i = 0; i < in->size; i++) {
+        if (in->instructions[i].type == FUN) {
+            if (in->instructions[i].args.length < 1) {
+                runtimeError(TOO_FEW_ARGS, "Expecting 1 or more args", &in->instructions[i], i);
+            }
+            if (in->instructions[i].args.args[0].type != FNREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a FunctionRef for arg 1", &in->instructions[i], i);
+            }
+            char* name = malloc(strlen(in->instructions[i].args.args[0].value.refName) + 1);
+            strcpy(name, in->instructions[i].args.args[0].value.refName);
+
+            size_t counter = 1;
+            GroundProgram gp = createGroundProgram();
+            addInstructionToProgram(&gp, in->instructions[i]);
+            size_t errorOffset = i;
+            i++;
+            while (counter > 0) {
+                if (i >= in->size) {
+                    runtimeError(PREMATURE_EOF, "Reached end of scope before function definition ended", &in->instructions[i - 1], i - 1);
+                }
+                if (in->instructions[i].type == FUN) {
+                    counter++;
+                }
+                if (in->instructions[i].type == ENDFUN) {
+                    counter--;
+                }
+                addInstructionToProgram(&gp, in->instructions[i]);
+                i++;
+            }
+            i--;
+
+            GroundFunction* function = parseFunction(&gp, errorOffset);
+            function->startLine = i;
+            function->closure = copyGroundScope(inScope);
+            GroundValue gv = createFunctionGroundValue(function);
+
+            addVariable(scope.variables, name, gv);
+        }
+        /*
         if (in->instructions[i].type == FUN) {
             int count = 1;
             while (count > 0) {
@@ -577,6 +580,7 @@ GroundValue interpretGroundProgram(GroundProgram* in, GroundScope* inScope) {
                 }
             }
         }
+        */
         if (in->instructions[i].type == STRUCT) {
             int count = 1;
             while (count > 0) {
@@ -1789,11 +1793,6 @@ GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scop
             if (in->args.args[in->args.length - 1].type != DIRREF) {
                 runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef as the last arg", in, currentInstruction);
             }
-            GroundVariable* variables = NULL;
-            GroundLabel* labels = NULL;
-            GroundScope newScope;
-            newScope.variables = &variables;
-            newScope.labels = &labels;
             GroundVariable* var = findVariable(*scope->variables, in->args.args[0].value.refName);
             if (var == NULL) {
                 runtimeError(UNKNOWN_VARIABLE, "Function not found", in, currentInstruction);
@@ -1841,6 +1840,7 @@ GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scop
                 }
                 free(argsList.values); 
             } else {
+                GroundScope newScope = copyGroundScope(&function->closure);
                 for (size_t i = 0; i < function->argSize; i++) {
                     if (in->args.args[i + 1].type != VALUE) {
                         runtimeError(ARG_TYPE_MISMATCH, "Expecting a Value", in, currentInstruction);

src/interpreter.h

@@ -1,6 +1,5 @@
 #ifndef INTERPRETER_H
 #define INTERPRETER_H
-#define MAX_ID_LEN 64
 
 #include "types.h"
 #include "parser.h"
@@ -14,24 +13,6 @@ typedef enum GroundDebugInstructionType {
     DUMP, INSPECT, EVAL, CONTINUE, EXIT, STEP, VIEW, HELP, UNKNOWN
 } GroundDebugInstructionType;
 
-typedef struct GroundLabel {
-    char id[MAX_ID_LEN];
-    int lineNum;
-    UT_hash_handle hh;
-} GroundLabel;
-
-typedef struct GroundVariable {
-    char id[MAX_ID_LEN];
-    GroundValue value;
-    UT_hash_handle hh;
-} GroundVariable;
-
-typedef struct GroundScope {
-    GroundLabel** labels;
-    GroundVariable** variables;
-    bool isMainScope;
-} GroundScope;
-
 typedef struct GroundDebugInstruction {
     GroundDebugInstructionType type;
     char* arg;
@@ -42,7 +23,6 @@ GroundFunction* parseFunction(GroundProgram* in, size_t errorOffset);
 GroundValue interpretGroundProgram(GroundProgram* in, GroundScope* inScope);
 GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scope);
 
-void addVariable(GroundVariable **head, const char *id, GroundValue data);
 
 
 

src/types.c

@@ -709,3 +709,24 @@ bool checkTypes(GroundValue* left, GroundValue* right) {
     }
     return true;
 }
+
+GroundScope copyGroundScope(GroundScope* scope) {
+    GroundScope newScope = {
+        .labels = malloc(sizeof(GroundLabel*)),
+        .variables = malloc(sizeof(GroundVariable*)),
+        .isMainScope = false
+    };
+    *newScope.variables = NULL;
+    *newScope.labels = NULL;
+
+    if (scope == NULL) {
+        printf("oh no scope is null\n");
+    }
+
+    GroundVariable *var, *tmp = NULL;
+    HASH_ITER(hh, *scope->variables, var, tmp) {
+        addVariable(newScope.variables, var->id, var->value);
+    }
+
+    return newScope;
+}

src/types.h

@@ -8,6 +8,8 @@
 #include <string.h>
 #include "include/uthash.h"
 
+#define MAX_ID_LEN 64
+
 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, ITOC, CTOI, TOSTRING, FUN, RETURN, ENDFUN, PUSHARG, CALL, STRUCT, ENDSTRUCT, INIT, GETFIELD, SETFIELD, USE, EXTERN, CREATELABEL, PAUSE, DROP, ERRORCMD
 } GroundInstType;
@@ -77,6 +79,24 @@ typedef struct GroundValue {
     } data;
 } GroundValue;
 
+typedef struct GroundLabel {
+    char id[MAX_ID_LEN];
+    int lineNum;
+    UT_hash_handle hh;
+} GroundLabel;
+
+typedef struct GroundVariable {
+    char id[MAX_ID_LEN];
+    GroundValue value;
+    UT_hash_handle hh;
+} GroundVariable;
+
+typedef struct GroundScope {
+    GroundLabel** labels;
+    GroundVariable** variables;
+    bool isMainScope;
+} GroundScope;
+
 /*
  * Indicates status when accessing a list.
  * Associated functions:
@@ -145,6 +165,7 @@ typedef struct GroundFunction {
     GroundProgram program;
     size_t startLine;
     bool isNative;
+    GroundScope closure;
     NativeGroundFunction nativeFn;
 } GroundFunction;
 
@@ -284,5 +305,10 @@ bool checkFnTypes(GroundValue* left, GroundFunctionArgs* arg);
 // Compares types of two values.
 bool checkTypes(GroundValue* left, GroundValue* right);
 
+// Adds variable to GroundScope
+void addVariable(GroundVariable **head, const char *id, GroundValue data);
+
+// Deep copies a GroundScope
+GroundScope copyGroundScope(GroundScope* scope);
 
 #endif

tests/closure.grnd

@@ -0,0 +1,27 @@
+set &x 5
+
+PAUSE
+
+fun !dingle -function -int &a
+
+    PAUSE
+
+    fun !capture -int -int &b
+
+        PAUSE
+
+        add $a $b &tmp
+        add $tmp $x &tmp
+        return $tmp
+    endfun
+
+    return $capture
+
+endfun
+
+call !dingle 3 &result
+
+PAUSE
+
+call !result 5 &y
+println $y