Diff: jsmn.h

Revision:

0:46575249ef23

Child:

1:70061827a9c8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jsmn.h	Tue May 06 09:33:30 2014 +0000
@@ -0,0 +1,209 @@
+/* C-based low-memory footprint JSON parser for mbed
+ * Based on Serge Zaitsev's JSMN https://bitbucket.org/zserge/jsmn/wiki/Home
+ * JSMN is distributed under MIT license.
+ *
+ * Copyright (c) 2014 YoongHM
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MBED_JSMN_H
+#define MBED_JSMN_H
+
+/**
+ * A c-based low-memory low-memory footprint JSON parser for mbed.
+ *
+ * The code is based on Serge Zaitsev's JSMN on
+ * https://bitbucket.org/zserge/jsmn/wiki/Home
+ *
+ * @code
+ *#include "mbed.h"
+ *
+ *#include "jsmn.h"
+ *
+ *#define       MAXTOKEN       64
+ *
+ *const char *jsmn_type_str[] = {
+ *  "PRIMITIVE",
+ *  "OBJECT",
+ * "ARRAY",
+ *  "STRING"
+ *};
+ *
+ *int main()
+ *{
+ *  const char *js;            // Pointer to json string
+ *  int         r;             // Number of token parsed
+ *  jsmn_parser p;             // jsmn parser
+ *  jsmntok_t   t[MAXTOKEN];   // Parsed token
+ *
+ *  // JSON may contain multibyte characters or encoded unicode in
+ *  // \uXXXX format.
+ *  // mbed compiler may complain "invalid multibyte characters ...".
+ *  js =
+ *"{"
+ *"  \"menu\":"
+ *"  {"
+ *"    \"id\": 1234,"
+ *"    \"group\": \"File\","
+ *"    \"popup\":"
+ *"    {"
+ *"      \"menuitem\":"
+ *"      ["
+ *"        {\"value\": true,    \"onclick\"  : \"বিশাল\"},"
+ *"        {\"value\": false,   0x1328       : \"groß\"},"
+ *"        {\"value\": null,    \"15\u00f8C\": \"3\u0111\"},"
+ *"        {\"value\": \"測試\", -12.34       :  99}"
+ *"      ]"
+ *"    }"
+ *"  }"
+ *"}";
+ *
+ *  jsmn_init(&p);
+ *  r = jsmn_parse(&p, js, strlen(js), t, MAXTOKEN);
+ *
+ *  printf("Parsed %d tokens\n", r);
+ *  
+ *  printf("            TYPE       START   END  SIZE PAR\n");
+ *  printf("           ----------  -----  ----  ---- ---\n");
+ *
+ *  char        ch;
+ *  jsmntok_t   at;            // A token for general use
+ *  for (int i = 0; i < r; i++)
+ *  {
+ *    at = t[i];
+ *    printf("Token %2d = %-10.10s (%4d - %4d, %3d, %2d) --> ",
+ *           i, jsmn_type_str[at.type],
+ *           at.start, at.end,
+ *           at.size, at.parent);
+ *
+ *    switch (at.type)
+ *    {
+ *      case JSMN_STRING:
+ *        printf("%-10.*s\n", at.end - at.start + 2, js + at.start - 1);
+ *        break;
+ *
+ *      case JSMN_PRIMITIVE:
+ *        ch = *(js + at.start);
+ *
+ *        if (isdigit(ch) || ch == '-') 
+ *          printf("%-10.*s\n", at.end - at.start, js + at.start);
+ *        else if (tolower(ch) == 'n')
+ *          printf("null\n");
+ *        else if (tolower(ch) == 't')
+ *          printf("true\n");
+ *        else if (tolower(ch) == 'f')
+ *          printf("false\n");
+ *        break;
+ *
+ *      default:
+ *        printf("\n");
+ *        break;
+ *    }
+ *  }
+ * 
+ *  while (1)
+ *    ;
+ *} 
+ * @endcode
+ */
+
+/** jsmntype_t - JSON type recongized by JSMN.
+ *  There are
+ *  - Primitive: number, boolean (true/false) or null
+ *  - Object
+ *  - Array
+ *  - String
+ */
+typedef enum {
+  JSMN_PRIMITIVE = 0,
+  JSMN_OBJECT    = 1,
+  JSMN_ARRAY     = 2,
+  JSMN_STRING    = 3,
+  JSMN_INVALID   = 4
+} jsmntype_t;
+
+
+/** Error message return by JSMN API
+ * 
+ */
+#define  JSMN_ERR_OKAY    0  /* No problem                            */
+#define  JSMN_ERR_NOMEM  -1  /* Not enough tokens were provided       */
+#define  JSMN_ERR_INVAL  -2  /* Invalid character inside JSON string  */
+#define  JSMN_ERR_PART   -3  /* Incomplete JSON packet                */ 
+
+
+/** jsmntok_t - JSON token structure.
+ * 
+ * It is a c structure that contained parsed JSON token.
+ *
+ * @param   type    type (primitive, object, array, string)
+ * @param   start   start position in JSON data string, excl " if is a string
+ * @param   end     end position in JSON data string, incl " if is a string
+ * @param   size    number of token directly under it
+ * @param   parent  link to its direct parent token number
+ */
+typedef struct {
+  jsmntype_t type;
+  int        start;          /* Token's start pos;excl " if is a str  */
+  int        end;            /* Token's last  pos;incl " if is a str  */
+  int        size;           /* Number of token directly under it     */
+  int        parent;         /* Nth-token which is its direct parent  */
+} jsmntok_t;
+
+
+/** JSON parser - JSON parser structure.
+ *
+ * Contains an array of token blocks available. Also stores
+ * the string being parsed now and current position in that string
+ */
+typedef struct {
+  unsigned int pos;          /* offset in the JSON string */
+  unsigned int toknext;      /* next token to allocate */
+  int          toksuper;     /* superior token node, (parent or array)*/
+} jsmn_parser;
+
+
+/** Initialize jsmn_parser structure for a new JSON parsing
+ *
+ * @param *parser  jsmn_parser structure
+ */
+void 
+jsmn_init
+(jsmn_parser *parser
+);
+
+/** Parse a given JSON data string into array of jsmntok_t tokens.
+ * 
+ * @param *parser  jsmn_parser structure
+ * @param *js      JSON data string
+ * @param  len     string length of *js
+ * @param *tokens  tokens to hold the parsed data 
+ */
+int
+jsmn_parse
+(jsmn_parser *parser
+,const char  *js
+,size_t       len
+,jsmntok_t   *tokens
+,unsigned int num_tokens
+);
+
+
+#endif // JSMN_H
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