json: new module for parsing and generating JSON

[ccan] / ccan / json / _info

diff --git a/ccan/json/_info b/ccan/json/_info
new file mode 100644 (file)
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+++ b/ccan/json/_info
@@ -0,0 +1,118 @@
+#include <string.h>
+#include "config.h"
+
+/**
+ * json - Parse and generate JSON (JavaScript Object Notation)
+ *
+ * This is a library for encoding and decoding JSON that strives to be
+ * easy to learn, use, and incorporate into an application.
+ *
+ * JSON (JavaScript Object Notation) facilitates passing data among different
+ * programming languages, particularly JavaScript.  It looks like this:
+ *
+ *     [
+ *         {
+ *             "id":           1,
+ *             "firstname":    "John",
+ *             "lastname":     "Smith",
+ *             "email":        "john@example.com",
+ *             "likes_pizza":  false
+ *         },
+ *         {
+ *             "id":           2,
+ *             "firstname":    "Linda",
+ *             "lastname":     "Jones",
+ *             "email":        null,
+ *             "likes_pizza":  true
+ *         }
+ *     ]
+ *
+ * Example:
+ *     #include <ccan/json/json.h>
+ *     #include <math.h>
+ *     #include <stdio.h>
+ *     #include <stdlib.h>
+ *     
+ *     static int find_number(JsonNode *object, const char *name, double *out)
+ *     {
+ *             JsonNode *node = json_find_member(object, name);
+ *             if (node && node->tag == JSON_NUMBER) {
+ *                     *out = node->number_;
+ *                     return 1;
+ *             }
+ *             return 0;
+ *     }
+ *     
+ *     static void solve_pythagorean(JsonNode *triple)
+ *     {
+ *             double a = 0, b = 0, c = 0;
+ *             int a_given, b_given, c_given;
+ *             
+ *             if (triple->tag != JSON_OBJECT) {
+ *                     fprintf(stderr, "Error: Expected a JSON object.\n");
+ *                     exit(EXIT_FAILURE);
+ *             }
+ *             
+ *             a_given = find_number(triple, "a", &a);
+ *             b_given = find_number(triple, "b", &b);
+ *             c_given = find_number(triple, "c", &c);
+ *             
+ *             if (a_given + b_given + c_given != 2) {
+ *                     fprintf(stderr, "Error: I need two sides to compute the length of the third.\n");
+ *                     exit(EXIT_FAILURE);
+ *             }
+ *             
+ *             if (a_given && b_given) {
+ *                     c = sqrt(a*a + b*b);
+ *                     json_append_member(triple, "c", json_mknumber(c));
+ *             } else if (a_given && c_given) {
+ *                     b = sqrt(c*c - a*a);
+ *                     json_append_member(triple, "b", json_mknumber(b));
+ *             } else if (b_given && c_given) {
+ *                     a = sqrt(c*c - b*b);
+ *                     json_append_member(triple, "a", json_mknumber(a));
+ *             }
+ *     }
+ *     
+ *     int main(void)
+ *     {
+ *             JsonNode *triples = json_mkarray();
+ *             
+ *             json_append_element(triples, json_decode("{\"a\": 3, \"b\": 4}"));
+ *             json_append_element(triples, json_decode("{\"a\": 5, \"c\": 13}"));
+ *             json_append_element(triples, json_decode("{\"b\": 24, \"c\": 25}"));
+ *             
+ *             JsonNode *triple;
+ *             json_foreach(triple, triples)
+ *                     solve_pythagorean(triple);
+ *             
+ *             char *tmp = json_stringify(triples, "\t");
+ *             puts(tmp);
+ *             free(tmp);
+ *             
+ *             json_delete(triples);
+ *             return 0;
+ *     }
+ *
+ * Author: Joey Adams
+ * Version: 0.1
+ * License: MIT
+ */
+int main(int argc, char *argv[])
+{
+       /* Expect exactly one argument */
+       if (argc != 2)
+               return 1;
+
+       if (strcmp(argv[1], "depends") == 0) {
+               /* Nothing */
+               return 0;
+       }
+       
+       if (strcmp(argv[1], "libs") == 0) {
+               printf("m\n"); /* Needed for sqrt() used in example code above. */
+               return 0;
+       }
+
+       return 1;
+}