Implemented native C functions called from Toy scripts

There's only example functions for now, but I'll add type-specific
functions later.

repl/standard_library.c

@@ -0,0 +1,53 @@
+#include "standard_library.h"
+#include "toy_console_colors.h"
+
+#include "toy_print.h"
+#include "toy_scope.h"
+#include "toy_stack.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct CallbackPairs {
+	const char* name;
+	Toy_nativeCallback callback;
+} CallbackPairs;
+
+//example callbacks
+void hello(Toy_VM* vm) {
+	(void)vm;
+	Toy_print("Hello world!");
+}
+
+void debug(Toy_VM* vm) {
+	(void)vm;
+	Toy_print("This function returns the integer '42' to the calling scope.");
+	Toy_pushStack(&vm->stack, TOY_VALUE_FROM_INTEGER(42));
+}
+
+CallbackPairs callbackPairs[] = {
+	{"hello", hello},
+	{"debug", debug},
+	{NULL, NULL},
+};
+
+//exposed functions
+void initStandardLibrary(Toy_VM* vm) {
+	if (vm == NULL || vm->scope == NULL || vm->memoryBucket == NULL) {
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Can't initialize standard library, exiting\n" TOY_CC_RESET);
+		exit(-1);
+	}
+
+	//declare each pair
+	for (int i = 0; callbackPairs[i].name; i++) {
+		//cheat
+		Toy_String key = (Toy_String){
+			.leaf = { ._padding = { .type = TOY_STRING_LEAF, .length = strlen(callbackPairs[i].name), .refCount = 1, .cachedHash = 0 }, .data = callbackPairs[i].name }
+		};
+
+		Toy_Function* fn = Toy_createFunctionFromCallback(&(vm->memoryBucket), callbackPairs[i].callback);
+
+		Toy_declareScope(vm->scope, &key, TOY_VALUE_FUNCTION, TOY_VALUE_FROM_FUNCTION(fn), true);
+	}
+}