added example for null value to marshaller demo

Makefile

@@ -37,6 +37,15 @@ obj/%.o: src/%.c obj
 obj:
 	@mkdir -p obj
 
+marshaller-demo: marshaller/gen/demo.tab.c marshaller/demo/demo.c marshaller/marshaller.c $(A_LIB_NAME)
+	$(CC) $(CFLAGS) -Imarshaller/demo/ -Isrc/ -Imarshaller/ -o $@ $^
+
+marshaller/gen/demo.tab.c: marshaller/demo/demo.h marshaller/marshaller-gen
+	./marshaller/marshaller-gen -o $@ $<
+	
+marshaller/marshaller-gen:
+	$(MAKE) -C marshaller/ marshaller-gen
+
 clean:
 	@echo "Cleaning up..."
 	@rm -f obj/*.o
@@ -45,3 +54,4 @@ clean:
 	@rm -f $(BIN_NAME)
 	@rm -f $(A_LIB_NAME)
 	@rm -f $(SO_LIB_NAME)
+	$(MAKE) -C marshaller/ clean

marshaller/Makefile

@@ -3,9 +3,9 @@ YACC = bison
 YFLAGS = -y -d
 CC = gcc
 
-BIN_NAME = marshaller
+BIN_NAME = marshaller-gen
 
-marshaller: src/codegen.c gen/lex.yy.c gen/y.tab.c
+$(BIN_NAME): src/codegen.c gen/lex.yy.c gen/y.tab.c
 	$(CC) -Isrc/ -o $@ $^
 
 gen/y.tab.c gen/y.tab.h: src/parser.y
@@ -19,4 +19,3 @@ gen/lex.yy.c: src/scanner.l gen/y.tab.h
 
 clean:
 	rm -f gen/* $(BIN_NAME)
-

marshaller/demo/demo.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <json.h>
+#include <marshaller.h>
+
+#include "demo.h"
+
+
+int main() {
+	const char* json = "{\
+		\"name\": \"How To Write A JSON Marshaller In C\",\
+		\"content\": \"TODO\",\
+		\"views\": null,\
+		\"user\": {\
+			\"uid\": 1000,\
+			\"username\": \"overflowerror\",\
+			\"email\": \"overflow@persei.net\"\
+		}\
+	}";
+	
+	post_t* post = json_unmarshall(post_t, json);
+	
+	printf("Name:          %s\n", post->name);
+	printf("Content:       %s\n", post->content);
+	printf("Views:         %s (%ld)\n", post->views == NULL ? "null" : "", post->views == NULL ? 0 : *post->views);
+	printf("User.Uid:      %lld\n", post->user.uid);
+	printf("User.Username: %s\n", post->user.username);
+	printf("User.Email:    %s\n", post->user.email);
+	printf("\n");
+	
+	post->content = "Just do it.";
+	
+	char* newJson = json_marshall(post_t, post);
+	printf("%s\n", newJson);
+	
+	free(newJson);
+
+	return 0;
+}

marshaller/demo/demo.h

@@ -0,0 +1,18 @@
+#ifndef DEMO_H
+#define DEMO_H
+
+
+typedef struct {
+	long long uid;
+	const char* username;
+	const char* email;
+} user_t;
+
+typedef struct {
+	const char* name;
+	const char* content;
+	long* views;
+	user_t user;
+} post_t;
+
+#endif

src/json.h

@@ -1,6 +1,7 @@
 #ifndef JSON_H
 #define JSON_H
 
+#include <stdlib.h>
 #include <stdbool.h>
 
 typedef enum {