Refactor

Move json_value and obj_t to same file
 - Rename json_obj.* -> json_value.*
 - Move `print_json_value(...)` to json_value.*

Move `err_ctx(...)` to util.*

parse.h now only exposes `parse_json_value(...)`

include/json_value.h

@@ -0,0 +1,41 @@
+
+#ifndef _JSON_VALUE_H
+#define _JSON_VALUE_H
+
+#include <stdbool.h> // bool
+
+#define OBJ_SIZE 64
+
+typedef struct obj_entry {
+    char const* key;
+    struct json_value* val;
+    struct obj_entry* next;
+} * __p_obj_entry;
+
+typedef __p_obj_entry obj_t[OBJ_SIZE];
+
+enum json_type { object,
+    array,
+    string,
+    number,
+    boolean,
+    null };
+
+struct json_value {
+    enum json_type type;
+    union {
+        obj_t* object;
+        struct json_value** array;
+        char* string;
+        bool boolean;
+        double number;
+    };
+};
+
+void* obj_at(obj_t m, char* const key);
+bool obj_insert(obj_t m, char* const key, struct json_value* value);
+void obj_delete(obj_t m);
+
+void print_json(struct json_value val, int indent);
+
+#endif