Added terminal print callbacks

Resolved #127

source/toy_print.c

@@ -0,0 +1,51 @@
+#include "toy_print.h"
+
+#include <stdio.h>
+
+static void outDefault(const char* msg) {
+	fprintf(stdout, "%s", msg);
+}
+
+static void errDefault(const char* msg) {
+	fprintf(stderr, "%s", msg);
+}
+
+static Toy_callbackType printCallback = outDefault;
+static Toy_callbackType errorCallback = errDefault;
+static Toy_callbackType assertCallback = errDefault;
+
+void Toy_print(const char* msg) {
+	printCallback(msg);
+}
+
+void Toy_error(const char* msg) {
+	errorCallback(msg);
+}
+
+void Toy_assertFailure(const char* msg) {
+	assertCallback(msg);
+}
+
+void Toy_setPrintCallback(Toy_callbackType cb) {
+	printCallback = cb;
+}
+
+void Toy_setErrorCallback(Toy_callbackType cb) {
+	errorCallback = cb;
+}
+void Toy_setAssertFailureCallback(Toy_callbackType cb) {
+	assertCallback = cb;
+}
+
+void Toy_resetPrintCallback() {
+	printCallback = outDefault;
+}
+
+void Toy_resetErrorCallback() {
+	errorCallback = errDefault;
+}
+
+void Toy_resetAssertFailureCallback() {
+	assertCallback = errDefault;
+}
+