Add JSON API

src/json.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "arch.h"
+#include "str.h"
+
+#ifndef MG_JSON_MAX_DEPTH
+#define MG_JSON_MAX_DEPTH 30
+#endif
+
+// Error return values - negative. Successful returns are >= 0
+enum { MG_JSON_TOO_DEEP = -1, MG_JSON_INVALID = -2, MG_JSON_NOT_FOUND = -3 };
+int mg_json_get(const char *buf, int len, const char *path, int *toklen);
+
+bool mg_json_get_num(struct mg_str json, const char *path, double *v);
+bool mg_json_get_bool(struct mg_str json, const char *path, bool *v);
+char *mg_json_get_str(struct mg_str json, const char *path);
+char *mg_json_get_hex(struct mg_str json, const char *path);