| api.md (6cec9cad762b6476313fb1f8e931a1647822db6b) | api.md (3dcf5eb70598c88befd62f61f81e283e568ec519) |
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| 1# API documentation 2 3**Table of Contents** *generated with [DocToc](http://doctoc.herokuapp.com/)* 4 5- [Synopsis](#synopsis) 6- [Description](#description) 7 - [Parser functions](#parser-functions) 8 - [Emitting functions](#emitting-functions) --- 38 unchanged lines hidden (view full) --- 47Libucl is a parser and `C` API to parse and generate `ucl` objects. Libucl consist of several groups of functions: 48 49### Parser functions 50Used to parse `ucl` files and provide interface to extract `ucl` object. Currently, `libucl` can parse only full `ucl` documents, for instance, it is impossible to parse a part of document and therefore it is impossible to use `libucl` as a streaming parser. In future, this limitation can be removed. 51 52### Emitting functions 53Convert `ucl` objects to some textual or binary representation. Currently, libucl supports the following exports: 54 | 1# API documentation 2 3**Table of Contents** *generated with [DocToc](http://doctoc.herokuapp.com/)* 4 5- [Synopsis](#synopsis) 6- [Description](#description) 7 - [Parser functions](#parser-functions) 8 - [Emitting functions](#emitting-functions) --- 38 unchanged lines hidden (view full) --- 47Libucl is a parser and `C` API to parse and generate `ucl` objects. Libucl consist of several groups of functions: 48 49### Parser functions 50Used to parse `ucl` files and provide interface to extract `ucl` object. Currently, `libucl` can parse only full `ucl` documents, for instance, it is impossible to parse a part of document and therefore it is impossible to use `libucl` as a streaming parser. In future, this limitation can be removed. 51 52### Emitting functions 53Convert `ucl` objects to some textual or binary representation. Currently, libucl supports the following exports: 54 |
| 55- `JSON` - valid json format (can possibly loose some original data, such as implicit arrays) 56- `Config` - human-readable configuration format (losseless) | 55- `JSON` - valid json format (can possibly lose some original data, such as implicit arrays) 56- `Config` - human-readable configuration format (lossless) |
| 57- `YAML` - embedded yaml format (has the same limitations as `json` output) 58 59### Conversion functions 60Help to convert `ucl` objects to C types. These functions are used to convert `ucl_object_t` to C primitive types, such as numbers, strings or boolean values. 61 62### Generation functions | 57- `YAML` - embedded yaml format (has the same limitations as `json` output) 58 59### Conversion functions 60Help to convert `ucl` objects to C types. These functions are used to convert `ucl_object_t` to C primitive types, such as numbers, strings or boolean values. 61 62### Generation functions |
| 63Allow creating of `ucl` objects from C types and creating of complex `ucl` objects, such as hashes or arrays from primitive `ucl` objects, such as numbers or strings. | 63Allow creation of `ucl` objects from C types and creating of complex `ucl` objects, such as hashes or arrays from primitive `ucl` objects, such as numbers or strings. |
| 64 65### Iteration functions 66Iterate over `ucl` complex objects or over a chain of values, for example when a key in an object has multiple values (that can be treated as implicit array or implicit consolidation). 67 68### Validation functions 69Validation functions are used to validate some object `obj` using json-schema compatible object `schema`. Both input and schema must be UCL objects to perform validation. 70 71### Utility functions --- 71 unchanged lines hidden (view full) --- 143 144### ucl_parser_add_file 145 146~~~C 147bool ucl_parser_add_file (struct ucl_parser *parser, 148 const char *filename); 149~~~ 150 | 64 65### Iteration functions 66Iterate over `ucl` complex objects or over a chain of values, for example when a key in an object has multiple values (that can be treated as implicit array or implicit consolidation). 67 68### Validation functions 69Validation functions are used to validate some object `obj` using json-schema compatible object `schema`. Both input and schema must be UCL objects to perform validation. 70 71### Utility functions --- 71 unchanged lines hidden (view full) --- 143 144### ucl_parser_add_file 145 146~~~C 147bool ucl_parser_add_file (struct ucl_parser *parser, 148 const char *filename); 149~~~ 150 |
| 151Load file `filename` and parse it with the specified `parser`. This function uses `mmap` call to load file, therefore, it should not be `shrinked` during parsing. Otherwise, `libucl` can cause memory corruption and terminate the calling application. This function is also used by the internal handler of `include` macro, hence, this macro has the same limitation. | 151Load file `filename` and parse it with the specified `parser`. This function uses `mmap` call to load file, therefore, it should not be `shrunk` during parsing. Otherwise, `libucl` can cause memory corruption and terminate the calling application. This function is also used by the internal handler of `include` macro, hence, this macro has the same limitation. |
| 152 153### ucl_parser_get_object 154 155~~~C 156ucl_object_t* ucl_parser_get_object (struct ucl_parser *parser); 157~~~ 158 159If the `ucl` data has been parsed correctly this function returns the top object for the parser. Otherwise, this function returns the `NULL` pointer. The reference count for `ucl` object returned is increased by one, therefore, a caller should decrease reference by using `ucl_object_unref` to free object after usage. --- 60 unchanged lines hidden (view full) --- 220parser = ucl_parser_new (0); 221while (!feof (in) && r < (int)sizeof (inbuf)) { 222 r += fread (inbuf + r, 1, sizeof (inbuf) - r, in); 223} 224ucl_parser_add_chunk (parser, inbuf, r); 225fclose (in); 226 227if (ucl_parser_get_error (parser)) { | 152 153### ucl_parser_get_object 154 155~~~C 156ucl_object_t* ucl_parser_get_object (struct ucl_parser *parser); 157~~~ 158 159If the `ucl` data has been parsed correctly this function returns the top object for the parser. Otherwise, this function returns the `NULL` pointer. The reference count for `ucl` object returned is increased by one, therefore, a caller should decrease reference by using `ucl_object_unref` to free object after usage. --- 60 unchanged lines hidden (view full) --- 220parser = ucl_parser_new (0); 221while (!feof (in) && r < (int)sizeof (inbuf)) { 222 r += fread (inbuf + r, 1, sizeof (inbuf) - r, in); 223} 224ucl_parser_add_chunk (parser, inbuf, r); 225fclose (in); 226 227if (ucl_parser_get_error (parser)) { |
| 228 printf ("Error occured: %s\n", ucl_parser_get_error (parser)); | 228 printf ("Error occurred: %s\n", ucl_parser_get_error (parser)); |
| 229 ret = 1; 230} 231else { 232 obj = ucl_parser_get_object (parser); 233} 234 235if (parser != NULL) { 236 ucl_parser_free (parser); --- 9 unchanged lines hidden (view full) --- 246Libucl can transform UCL objects to a number of tectual formats: 247 248- configuration (`UCL_EMIT_CONFIG`) - nginx like human readable configuration file where implicit arrays are transformed to the duplicate keys 249- compact json: `UCL_EMIT_JSON_COMPACT` - single line valid json without spaces 250- formatted json: `UCL_EMIT_JSON` - pretty formatted JSON with newlines and spaces 251- compact yaml: `UCL_EMIT_YAML` - compact YAML output 252 253Moreover, libucl API allows to select a custom set of emitting functions allowing | 229 ret = 1; 230} 231else { 232 obj = ucl_parser_get_object (parser); 233} 234 235if (parser != NULL) { 236 ucl_parser_free (parser); --- 9 unchanged lines hidden (view full) --- 246Libucl can transform UCL objects to a number of tectual formats: 247 248- configuration (`UCL_EMIT_CONFIG`) - nginx like human readable configuration file where implicit arrays are transformed to the duplicate keys 249- compact json: `UCL_EMIT_JSON_COMPACT` - single line valid json without spaces 250- formatted json: `UCL_EMIT_JSON` - pretty formatted JSON with newlines and spaces 251- compact yaml: `UCL_EMIT_YAML` - compact YAML output 252 253Moreover, libucl API allows to select a custom set of emitting functions allowing |
| 254efficent and zero-copy output of libucl objects. Libucl uses the following structure to support this feature: | 254efficient and zero-copy output of libucl objects. Libucl uses the following structure to support this feature: |
| 255 256~~~C 257struct ucl_emitter_functions { 258 /** Append a single character */ 259 int (*ucl_emitter_append_character) (unsigned char c, size_t nchars, void *ud); 260 /** Append a string of a specified length */ 261 int (*ucl_emitter_append_len) (unsigned const char *str, size_t len, void *ud); 262 /** Append a 64 bit integer */ --- 30 unchanged lines hidden (view full) --- 293bool ucl_object_emit_full (const ucl_object_t *obj, enum ucl_emitter emit_type, 294 struct ucl_emitter_functions *emitter); 295~~~ 296 297This function is similar to the previous with the exception that it accepts the additional argument `emitter` that defines the concrete set of output functions. This emit function could be useful for custom structures or streams emitters (including C++ ones, for example). 298 299# Conversion functions 300 | 255 256~~~C 257struct ucl_emitter_functions { 258 /** Append a single character */ 259 int (*ucl_emitter_append_character) (unsigned char c, size_t nchars, void *ud); 260 /** Append a string of a specified length */ 261 int (*ucl_emitter_append_len) (unsigned const char *str, size_t len, void *ud); 262 /** Append a 64 bit integer */ --- 30 unchanged lines hidden (view full) --- 293bool ucl_object_emit_full (const ucl_object_t *obj, enum ucl_emitter emit_type, 294 struct ucl_emitter_functions *emitter); 295~~~ 296 297This function is similar to the previous with the exception that it accepts the additional argument `emitter` that defines the concrete set of output functions. This emit function could be useful for custom structures or streams emitters (including C++ ones, for example). 298 299# Conversion functions 300 |
| 301Conversion functions are used to convert UCL objects to primitive types, such as strings, numbers or boolean values. There are two types of conversion functions: | 301Conversion functions are used to convert UCL objects to primitive types, such as strings, numbers, or boolean values. There are two types of conversion functions: |
| 302 303- safe: try to convert an ucl object to a primitive type and fail if such a conversion is not possible 304- unsafe: return primitive type without additional checks, if the object cannot be converted then some reasonable default is returned (NULL for strings and 0 for numbers) 305 | 302 303- safe: try to convert an ucl object to a primitive type and fail if such a conversion is not possible 304- unsafe: return primitive type without additional checks, if the object cannot be converted then some reasonable default is returned (NULL for strings and 0 for numbers) 305 |
| 306Also there is a single `ucl_object_tostring_forced` function that converts any UCL object (including compound types - arrays and objects) to a string representation. For compound and numeric types this function performs emitting to a compact json format actually. | 306Also there is a single `ucl_object_tostring_forced` function that converts any UCL object (including compound types - arrays and objects) to a string representation. For objects, arrays, booleans and numeric types this function performs emitting to a compact json format actually. |
| 307 308Here is a list of all conversion functions: 309 310- `ucl_object_toint` - returns `int64_t` of UCL object 311- `ucl_object_todouble` - returns `double` of UCL object 312- `ucl_object_toboolean` - returns `bool` of UCL object 313- `ucl_object_tostring` - returns `const char *` of UCL object (this string is NULL terminated) | 307 308Here is a list of all conversion functions: 309 310- `ucl_object_toint` - returns `int64_t` of UCL object 311- `ucl_object_todouble` - returns `double` of UCL object 312- `ucl_object_toboolean` - returns `bool` of UCL object 313- `ucl_object_tostring` - returns `const char *` of UCL object (this string is NULL terminated) |
| 314- `ucl_object_tolstring` - returns `const char *` and `size_t` len of UCL object (string can be not NULL terminated) | 314- `ucl_object_tolstring` - returns `const char *` and `size_t` len of UCL object (string does not need to be NULL terminated) |
| 315- `ucl_object_tostring_forced` - returns string representation of any UCL object 316 317Strings returned by these pointers are associated with the UCL object and exist over its lifetime. A caller should not free this memory. 318 319# Generation functions 320 | 315- `ucl_object_tostring_forced` - returns string representation of any UCL object 316 317Strings returned by these pointers are associated with the UCL object and exist over its lifetime. A caller should not free this memory. 318 319# Generation functions 320 |
| 321It is possible to generate UCL objects from C primitive types. Moreover, libucl permits to create and modify complex UCL objects, such as arrays or associative objects. | 321It is possible to generate UCL objects from C primitive types. Moreover, libucl allows creation and modifying complex UCL objects, such as arrays or associative objects. |
| 322 323## ucl_object_new 324~~~C 325ucl_object_t * ucl_object_new (void) 326~~~ 327 328Creates new object of type `UCL_NULL`. This object should be released by caller. 329 --- 15 unchanged lines hidden (view full) --- 345 346This object should be released by caller. 347 348## Primitive objects generation 349Libucl provides the functions similar to inverse conversion functions called with the specific C type: 350- `ucl_object_fromint` - converts `int64_t` to UCL object 351- `ucl_object_fromdouble` - converts `double` to UCL object 352- `ucl_object_fromboolean` - converts `bool` to UCL object | 322 323## ucl_object_new 324~~~C 325ucl_object_t * ucl_object_new (void) 326~~~ 327 328Creates new object of type `UCL_NULL`. This object should be released by caller. 329 --- 15 unchanged lines hidden (view full) --- 345 346This object should be released by caller. 347 348## Primitive objects generation 349Libucl provides the functions similar to inverse conversion functions called with the specific C type: 350- `ucl_object_fromint` - converts `int64_t` to UCL object 351- `ucl_object_fromdouble` - converts `double` to UCL object 352- `ucl_object_fromboolean` - converts `bool` to UCL object |
| 353- `ucl_object_fromstring` - converts `const char *` to UCL object (this string is NULL terminated) 354- `ucl_object_fromlstring` - converts `const char *` and `size_t` len to UCL object (string can be not NULL terminated) | 353- `ucl_object_fromstring` - converts `const char *` to UCL object (this string should be NULL terminated) 354- `ucl_object_fromlstring` - converts `const char *` and `size_t` len to UCL object (string does not need to be NULL terminated) |
| 355 356Also there is a function to generate UCL object from a string performing various parsing or conversion operations called `ucl_object_fromstring_common`. 357 358## ucl_object_fromstring_common 359~~~C 360ucl_object_t * ucl_object_fromstring_common (const char *str, 361 size_t len, enum ucl_string_flags flags) 362~~~ 363 | 355 356Also there is a function to generate UCL object from a string performing various parsing or conversion operations called `ucl_object_fromstring_common`. 357 358## ucl_object_fromstring_common 359~~~C 360ucl_object_t * ucl_object_fromstring_common (const char *str, 361 size_t len, enum ucl_string_flags flags) 362~~~ 363 |
| 364This function is used to convert a string `str` of size `len` to an UCL objects applying `flags` conversions. If `len` is equal to zero then a `str` is assumed as NULL-terminated. This function supports the following flags (a set of flags can be specified using logical `OR` operation): | 364This function is used to convert a string `str` of size `len` to a UCL object applying `flags` conversions. If `len` is equal to zero then a `str` is assumed as NULL-terminated. This function supports the following flags (a set of flags can be specified using logical `OR` operation): |
| 365 366- `UCL_STRING_ESCAPE` - perform JSON escape 367- `UCL_STRING_TRIM` - trim leading and trailing whitespaces 368- `UCL_STRING_PARSE_BOOLEAN` - parse passed string and detect boolean 369- `UCL_STRING_PARSE_INT` - parse passed string and detect integer number 370- `UCL_STRING_PARSE_DOUBLE` - parse passed string and detect integer or float number 371- `UCL_STRING_PARSE_TIME` - parse time values as floating point numbers 372- `UCL_STRING_PARSE_NUMBER` - parse passed string and detect number (both float, integer and time types) --- 7 unchanged lines hidden (view full) --- 380Iteration are used to iterate over UCL compound types: arrays and objects. Moreover, iterations could be performed over the keys with multiple values (implicit arrays). To iterate over an object, an array or a key with multiple values there is a function `ucl_iterate_object`. 381 382## ucl_iterate_object 383~~~C 384const ucl_object_t* ucl_iterate_object (const ucl_object_t *obj, 385 ucl_object_iter_t *iter, bool expand_values); 386~~~ 387 | 365 366- `UCL_STRING_ESCAPE` - perform JSON escape 367- `UCL_STRING_TRIM` - trim leading and trailing whitespaces 368- `UCL_STRING_PARSE_BOOLEAN` - parse passed string and detect boolean 369- `UCL_STRING_PARSE_INT` - parse passed string and detect integer number 370- `UCL_STRING_PARSE_DOUBLE` - parse passed string and detect integer or float number 371- `UCL_STRING_PARSE_TIME` - parse time values as floating point numbers 372- `UCL_STRING_PARSE_NUMBER` - parse passed string and detect number (both float, integer and time types) --- 7 unchanged lines hidden (view full) --- 380Iteration are used to iterate over UCL compound types: arrays and objects. Moreover, iterations could be performed over the keys with multiple values (implicit arrays). To iterate over an object, an array or a key with multiple values there is a function `ucl_iterate_object`. 381 382## ucl_iterate_object 383~~~C 384const ucl_object_t* ucl_iterate_object (const ucl_object_t *obj, 385 ucl_object_iter_t *iter, bool expand_values); 386~~~ 387 |
| 388This function accept opaque iterator pointer `iter`. In the first call this iterator *must* be initialized to `NULL`. Iterator is changed by this function call. `ucl_iterate_object` returns the next UCL object in the compound object `obj` or `NULL` if all objects have been iterated. The reference count of the object returned is not increased, so a caller should not unref the object or modify its content (e.g. by inserting to another compound object). The object `obj` should not be changed during the iteration process as well. `expand_values` flag speicifies whether `ucl_iterate_object` should expand keys with multiple values. The general rule is that if you need to iterate throught the *object* or *explicit array*, then you always need to set this flag to `true`. However, if you get some key in the object and want to extract all its values then you should set `expand_values` to `false`. Mixing of iteration types are not permitted since the iterator is set according to the iteration type and cannot be reused. Here is an example of iteration over the objects using libucl API (assuming that `top` is `UCL_OBJECT` in this example): | 388This function accepts opaque iterator pointer `iter`. In the first call this iterator *must* be initialized to `NULL`. Iterator is changed by this function call. `ucl_iterate_object` returns the next UCL object in the compound object `obj` or `NULL` if all objects have been iterated. The reference count of the object returned is not increased, so a caller should not unref the object or modify its content (e.g. by inserting to another compound object). The object `obj` should not be changed during the iteration process as well. `expand_values` flag speicifies whether `ucl_iterate_object` should expand keys with multiple values. The general rule is that if you need to iterate through the *object* or *explicit array*, then you always need to set this flag to `true`. However, if you get some key in the object and want to extract all its values then you should set `expand_values` to `false`. Mixing of iteration types is not permitted since the iterator is set according to the iteration type and cannot be reused. Here is an example of iteration over the objects using libucl API (assuming that `top` is `UCL_OBJECT` in this example): |
| 389 390~~~C 391ucl_object_iter_t it = NULL, it_obj = NULL; 392const ucl_object_t *cur, *tmp; 393 394/* Iterate over the object */ 395while ((obj = ucl_iterate_object (top, &it, true))) { 396 printf ("key: \"%s\"\n", ucl_object_key (obj)); --- 10 unchanged lines hidden (view full) --- 407Currently, there is only one validation function called `ucl_object_validate`. It performs validation of object using the specified schema. This function is defined as following: 408 409## ucl_object_validate 410~~~C 411bool ucl_object_validate (const ucl_object_t *schema, 412 const ucl_object_t *obj, struct ucl_schema_error *err); 413~~~ 414 | 389 390~~~C 391ucl_object_iter_t it = NULL, it_obj = NULL; 392const ucl_object_t *cur, *tmp; 393 394/* Iterate over the object */ 395while ((obj = ucl_iterate_object (top, &it, true))) { 396 printf ("key: \"%s\"\n", ucl_object_key (obj)); --- 10 unchanged lines hidden (view full) --- 407Currently, there is only one validation function called `ucl_object_validate`. It performs validation of object using the specified schema. This function is defined as following: 408 409## ucl_object_validate 410~~~C 411bool ucl_object_validate (const ucl_object_t *schema, 412 const ucl_object_t *obj, struct ucl_schema_error *err); 413~~~ 414 |
| 415This function uses ucl object `schema`, that must be valid in terms of `json-schema` draft v4, to validate input object `obj`. If this function returns `true` then validation procedure has been succeed. Otherwise, `false` is returned and `err` is set to a specific value. If caller set `err` to NULL then this function does not set any error just returning `false`. Error is the structure defined as following: | 415This function uses ucl object `schema`, that must be valid in terms of `json-schema` draft v4, to validate input object `obj`. If this function returns `true` then validation procedure has been succeed. Otherwise, `false` is returned and `err` is set to a specific value. If a caller sets `err` to NULL then this function does not set any error just returning `false`. Error is the structure defined as following: |
| 416 417~~~C 418struct ucl_schema_error { 419 enum ucl_schema_error_code code; /* error code */ 420 char msg[128]; /* error message */ | 416 417~~~C 418struct ucl_schema_error { 419 enum ucl_schema_error_code code; /* error code */ 420 char msg[128]; /* error message */ |
| 421 ucl_object_t *obj; /* object where error occured */ | 421 ucl_object_t *obj; /* object where error occurred */ |
| 422}; 423~~~ 424 425Caller may use `code` field to get a numeric error code: 426 427~~~C 428enum ucl_schema_error_code { 429 UCL_SCHEMA_OK = 0, /* no error */ 430 UCL_SCHEMA_TYPE_MISMATCH, /* type of object is incorrect */ 431 UCL_SCHEMA_INVALID_SCHEMA, /* schema is invalid */ 432 UCL_SCHEMA_MISSING_PROPERTY,/* missing properties */ 433 UCL_SCHEMA_CONSTRAINT, /* constraint found */ 434 UCL_SCHEMA_MISSING_DEPENDENCY, /* missing dependency */ 435 UCL_SCHEMA_UNKNOWN /* generic error */ 436}; 437~~~ 438 | 422}; 423~~~ 424 425Caller may use `code` field to get a numeric error code: 426 427~~~C 428enum ucl_schema_error_code { 429 UCL_SCHEMA_OK = 0, /* no error */ 430 UCL_SCHEMA_TYPE_MISMATCH, /* type of object is incorrect */ 431 UCL_SCHEMA_INVALID_SCHEMA, /* schema is invalid */ 432 UCL_SCHEMA_MISSING_PROPERTY,/* missing properties */ 433 UCL_SCHEMA_CONSTRAINT, /* constraint found */ 434 UCL_SCHEMA_MISSING_DEPENDENCY, /* missing dependency */ 435 UCL_SCHEMA_UNKNOWN /* generic error */ 436}; 437~~~ 438 |
| 439`msg` is a stiring description of an error and `obj` is an object where error has been occurred. Error object is not allocated by libucl, so there is no need to free it after validation (a static object should thus be used). | 439`msg` is a string description of an error and `obj` is an object where error has occurred. Error object is not allocated by libucl, so there is no need to free it after validation (a static object should thus be used). |