mirror of
https://github.com/akheron/jansson.git
synced 2025-04-06 05:55:05 +00:00
Refactor json_pack()
* Implement a "scanner" that reads the format string, maintaining state * Split json_vnpack() to three separate functions for packing objects, arrays and simple values. This makes it more clear what is being packed, and the object and array structures become more evident. * Make the skipping of ignored character simpler, i.e. skip ':' and ',' independent of their context This patch shaves around 80 lines of code from the original implementation.
This commit is contained in:
Petri Lehtinen
parent
53383860e8
commit
7f3018a4fb
4 changed files with 176 additions and 253 deletions
12
src/error.c
12
src/error.c
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@ -1,6 +1,4 @@
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#include <string.h>
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#include <stdarg.h>
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#include "jansson_private.h"
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void jsonp_error_init(json_error_t *error, const char *source)
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@ -21,6 +19,14 @@ void jsonp_error_set(json_error_t *error, int line, int column,
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{
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va_list ap;
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va_start(ap, msg);
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jsonp_error_vset(error, line, column, msg, ap);
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va_end(ap);
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}
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void jsonp_error_vset(json_error_t *error, int line, int column,
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const char *msg, va_list ap)
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{
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if(!error)
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return;
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@ -32,7 +38,5 @@ void jsonp_error_set(json_error_t *error, int line, int column,
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error->line = line;
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error->column = column;
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va_start(ap, msg);
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vsnprintf(error->text, JSON_ERROR_TEXT_LENGTH, msg, ap);
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va_end(ap);
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}
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@ -9,6 +9,7 @@
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#define JANSSON_PRIVATE_H
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#include <stddef.h>
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#include <stdarg.h>
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#include "jansson.h"
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#include "hashtable.h"
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@ -66,5 +67,7 @@ const object_key_t *jsonp_object_iter_fullkey(void *iter);
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void jsonp_error_init(json_error_t *error, const char *source);
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void jsonp_error_set(json_error_t *error, int line, int column,
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const char *msg, ...);
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void jsonp_error_vset(json_error_t *error, int line, int column,
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const char *msg, va_list ap);
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#endif
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412
src/variadic.c
412
src/variadic.c
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@ -13,266 +13,168 @@
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#include <jansson.h>
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#include "jansson_private.h"
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static json_t *json_vnpack(json_error_t *error, ssize_t size, const char * const fmt, va_list *ap)
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typedef struct {
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const char *fmt;
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char token;
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json_error_t *error;
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int line;
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int column;
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} scanner_t;
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static void next_token(scanner_t *s)
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{
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json_t *root = NULL; /* root object */
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json_t *obj = NULL;
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const char *t = s->fmt;
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s->column++;
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/* Scanner variables */
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const char *tok = fmt;
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const char *etok;
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int etok_depth;
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/* skip space and ignored chars */
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while(*t == ' ' || *t == '\t' || *t == '\n' || *t == ',' || *t == ':') {
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if(*t == '\n') {
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s->line++;
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s->column = 1;
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}
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else
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s->column++;
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char *key = NULL; /* Current key in an object */
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char *s;
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int line = 1;
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int column = 1;
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/* Skip whitespace at the beginning of the string. */
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while(size && *tok == ' ') {
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tok++;
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size--;
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column++;
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t++;
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}
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if(size <= 0) {
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jsonp_error_set(error, 1, 1, "Empty format string!");
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return NULL;
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}
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s->token = *t;
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/* tok must contain either a container type, or a length-1 string for a
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* simple type. */
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if(*tok == '[')
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root = json_array();
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else if(*tok == '{')
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root = json_object();
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else
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{
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/* Simple object. Permit trailing spaces, otherwise complain. */
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if((ssize_t)strspn(tok+1, " ") < size-1)
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{
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jsonp_error_set(error, 1, 1,
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"Expected a single object, got %i", size);
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return NULL;
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t++;
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s->fmt = t;
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}
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static void set_error(scanner_t *s, const char *fmt, ...)
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{
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va_list ap;
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va_start(ap, fmt);
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jsonp_error_vset(s->error, s->line, s->column, fmt, ap);
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va_end(ap);
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}
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static json_t *pack(scanner_t *s, va_list *ap);
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static json_t *pack_object(scanner_t *s, va_list *ap)
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{
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json_t *object = json_object();
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next_token(s);
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while(s->token != '}') {
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const char *key;
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json_t *value;
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if(!s->token) {
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set_error(s, "Unexpected end of format string");
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goto error;
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}
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switch(*tok)
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{
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case 's': /* string */
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s = va_arg(*ap, char *);
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if(!s)
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{
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jsonp_error_set(error, 1, 1,
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"Refusing to handle a NULL string");
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return NULL;
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}
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return json_string(s);
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case 'n': /* null */
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return json_null();
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case 'b': /* boolean */
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obj = va_arg(*ap, int) ?
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json_true() : json_false();
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return obj;
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case 'i': /* integer */
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return json_integer(va_arg(*ap, int));
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case 'f': /* double-precision float */
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return json_real(va_arg(*ap, double));
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case 'O': /* a json_t object; increments refcount */
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obj = va_arg(*ap, json_t *);
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json_incref(obj);
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return obj;
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case 'o': /* a json_t object; doesn't increment refcount */
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obj = va_arg(*ap, json_t *);
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return obj;
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default: /* Whoops! */
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jsonp_error_set(error, 1, 1,
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"Didn't understand format character '%c'",
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*tok);
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return NULL;
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if(s->token != 's') {
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set_error(s, "Expected format 's', got '%c'\n", *s->fmt);
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goto error;
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}
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key = va_arg(*ap, const char *);
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if(!key) {
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set_error(s, "NULL object key");
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goto error;
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}
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next_token(s);
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value = pack(s, ap);
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if(!value)
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goto error;
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if(json_object_set_new(object, key, value)) {
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set_error(s, "Unable to add key \"%s\"", key);
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goto error;
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}
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next_token(s);
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}
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/* Move past container opening token */
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tok++;
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column++;
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return object;
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while(tok-fmt < size) {
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switch(*tok) {
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case '\n':
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line++;
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column = 0;
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break;
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case ' ': /* Whitespace */
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break;
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case ',': /* Element spacer */
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if(key)
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{
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jsonp_error_set(error, line, column,
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"Expected KEY, got COMMA!");
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json_decref(root);
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return NULL;
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}
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break;
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case ':': /* Key/value separator */
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if(!key)
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{
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jsonp_error_set(error, line, column,
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"Got key/value separator without "
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"a key preceding it!");
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json_decref(root);
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return NULL;
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}
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if(!json_is_object(root))
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{
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jsonp_error_set(error, line, column,
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"Got a key/value separator "
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"(':') outside an object!");
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json_decref(root);
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return NULL;
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}
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break;
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case ']': /* Close array or object */
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case '}':
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if(tok-fmt + (ssize_t)strspn(tok+1, " ") != size-1)
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{
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jsonp_error_set(error, line, column,
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"Unexpected close-bracket '%c'", *tok);
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json_decref(root);
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return NULL;
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}
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if((*tok == ']' && !json_is_array(root)) ||
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(*tok == '}' && !json_is_object(root)))
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{
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jsonp_error_set(error, line, column,
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"Stray close-array '%c' character", *tok);
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json_decref(root);
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return NULL;
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}
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return root;
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case '[':
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case '{':
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/* Shortcut so we don't mess up the column count in error
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* messages */
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if(json_is_object(root) && !key)
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goto common;
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/* Find corresponding close bracket */
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etok = tok+1;
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etok_depth = 1;
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while(etok_depth) {
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if(!*etok || etok-fmt >= size) {
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jsonp_error_set(error, line, column,
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"Couldn't find matching close bracket for '%c'",
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*tok);
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json_decref(root);
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return NULL;
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}
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if(*tok == *etok)
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etok_depth++;
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else if(*tok == '[' && *etok == ']') {
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etok_depth--;
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break;
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} else if(*tok == '{' && *etok == '}') {
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etok_depth--;
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break;
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}
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etok++;
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}
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/* Recurse */
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obj = json_vnpack(error, etok-tok+1, tok, ap);
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if(!obj) {
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/* error should already be set */
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error->column += column-1;
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error->line += line-1;
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json_decref(root);
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return NULL;
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}
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column += etok-tok;
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tok = etok;
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goto common;
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case 's':
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/* Handle strings specially, since they're used for both keys
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* and values */
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s = va_arg(*ap, char *);
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if(!s)
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{
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jsonp_error_set(error, line, column,
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"Refusing to handle a NULL string");
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json_decref(root);
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return NULL;
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}
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if(json_is_object(root) && !key)
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{
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/* It's a key */
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key = s;
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break;
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}
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obj = json_string(s);
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goto common;
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default:
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obj = json_vnpack(error, 1, tok, ap);
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if(!obj) {
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json_decref(root);
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return NULL;
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}
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common:
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/* Add to container */
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if(json_is_object(root)) {
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if(!key)
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{
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jsonp_error_set(error, line, column,
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"Expected key, got identifier '%c'!", *tok);
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json_decref(root);
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return NULL;
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}
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json_object_set_new(root, key, obj);
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key = NULL;
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}
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else
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{
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json_array_append_new(root, obj);
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}
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break;
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}
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tok++;
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column++;
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}
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/* Whoops -- we didn't match the close bracket! */
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jsonp_error_set(error, line, column, "Missing close array or object!");
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json_decref(root);
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error:
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json_decref(object);
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return NULL;
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}
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static json_t *pack_array(scanner_t *s, va_list *ap)
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{
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json_t *array = json_array();
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next_token(s);
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while(s->token != ']') {
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json_t *value;
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if(!s->token) {
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set_error(s, "Unexpected end of format string");
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goto error;
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}
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value = pack(s, ap);
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if(!value)
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goto error;
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if(json_array_append_new(array, value)) {
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set_error(s, "Unable to append to array");
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goto error;
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}
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next_token(s);
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}
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return array;
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error:
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json_decref(array);
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return NULL;
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}
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static json_t *pack(scanner_t *s, va_list *ap)
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{
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switch(s->token) {
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case '{':
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return pack_object(s, ap);
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case '[':
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return pack_array(s, ap);
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case 's': /* string */
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{
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const char *str = va_arg(*ap, const char *);
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if(!str)
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{
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set_error(s, "NULL string");
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return NULL;
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}
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return json_string(str);
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}
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case 'n': /* null */
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return json_null();
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case 'b': /* boolean */
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return va_arg(*ap, int) ? json_true() : json_false();
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case 'i': /* integer */
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return json_integer(va_arg(*ap, int));
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case 'f': /* double-precision float */
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return json_real(va_arg(*ap, double));
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case 'O': /* a json_t object; increments refcount */
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return json_incref(va_arg(*ap, json_t *));
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case 'o': /* a json_t object; doesn't increment refcount */
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return va_arg(*ap, json_t *);
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default: /* Whoops! */
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set_error(s, "Unrecognized format character '%c'", s->token);
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return NULL;
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}
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}
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static int json_vnunpack(json_t *root, json_error_t *error, ssize_t size, const char *fmt, va_list *ap)
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{
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@ -555,8 +457,9 @@ static int json_vnunpack(json_t *root, json_error_t *error, ssize_t size, const
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json_t *json_pack(json_error_t *error, const char *fmt, ...)
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{
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scanner_t s;
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json_t *value;
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va_list ap;
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json_t *obj;
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jsonp_error_init(error, "");
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@ -565,11 +468,24 @@ json_t *json_pack(json_error_t *error, const char *fmt, ...)
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return NULL;
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}
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s.error = error;
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s.fmt = fmt;
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s.line = 1;
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s.column = 0;
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next_token(&s);
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va_start(ap, fmt);
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obj = json_vpack(error, fmt, &ap);
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value = pack(&s, &ap);
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va_end(ap);
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return obj;
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next_token(&s);
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if(s.token) {
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set_error(&s, "Garbage after format string");
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return NULL;
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}
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return value;
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}
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int json_unpack(json_t *root, json_error_t *error, const char *fmt, ...)
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|
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@ -191,7 +191,7 @@ int main()
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if(json_pack(&error, "{ s: {}, s:[ii{} }", "foo", "bar", 12, 13))
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fail("json_pack failed to catch missing ]");
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if(error.line != 1 || error.column != 13)
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if(error.line != 1 || error.column != 19)
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fail("json_pack didn't get the error coordinates right!");
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if(json_pack(&error, "[[[[[ [[[[[ [[[[ }]]]] ]]]] ]]]]]"))
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|
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