Library
Module
Module type
Parameter
Class
Class type
Queries in JSON documents
type path = path_item list
An abstract type for paths into a JSON document. A sequence of sub-tree selectors to descend into a JSON tree.
and path_item = [
| `Field of string
A field in an object.
*)| `Index of int
An index in an array.
*)| `Star
Any / every field or index.
*)| `Next
The next element after an array.
*) ]
A JSON sub-tree selector. Indendent from any concrete format (JSON pointer, JSON path, etc.) The semantics depends on the use (selection, insertion, etc.)
val print_path_as_json_pointer :
?wildcards:bool ->
Stdlib.Format.formatter ->
path ->
unit
Pretty prints a path in JSON pointer format (RFC6901). May throw Unsupported_path_item
. Use ~wildcards:false
to deactivate the support of wildcard path items, which may lead to Unsupported_path_item
.
val print_path_as_json_path :
?wildcards:bool ->
Stdlib.Format.formatter ->
path ->
unit
Pretty prints a path in JSON path format. Use ~wildcards:false
to deactivate the support of wildcard path items, which may lead to Unsupported_path_item
.
val json_pointer_of_path : ?wildcards:bool -> path -> string
Pretty prints a path in JSON pointer format into a fresh string. May throw Unsupported_path_item
. Use ~wildcards:false
to deactivate the support of wildcard path items, which may lead to Unsupported_path_item
.
val path_of_json_pointer : ?wildcards:bool -> string -> path
Parses a path from a string in JSON pointer format. May throw Illegal_pointer_notation
. The string is expected to be ASCII compatible, including UTF-8. Use ~wildcards:false
to deactivate the support of wildcard path items, which may lead to Unsupported_path_item
.
val query : path -> Json_repr.ezjsonm -> Json_repr.ezjsonm
Extracts the value located at a given path. If multiple locations satisfy the path (in presence of wildcard path items), the chosen one is unspecified. May throw Not_found
.
This function works with JSON data represented in the Json_repr.ezjsonm
format. See functor Make
for using another representation.
val query_all : path -> Json_repr.ezjsonm -> Json_repr.ezjsonm list
Extracts the values located at a given path (may be more than one in presence of wildcard path items). The order is unspecified.
This function works with JSON data represented in the Json_repr.ezjsonm
format. See functor Make
for using another representation.
val insert :
path ->
Json_repr.ezjsonm ->
Json_repr.ezjsonm ->
Json_repr.ezjsonm
Insert a value at a given path. If multiple locations satisfy the path (in presence of wildcard path items), the chosen one is unspecified. Will create parent objects or arrays if needed, for instance inserting 3
at /a/b/c
in {}
will result in {"a":{"b":{"c":3}}}
. Inserting in an array at an index bigger than the previous size will expand the array, filling potential missing cells with `Null
. Inserting in an array at `Index n
where n
is negative inserts from the last element of the array. If a value is inserted at a location where there is already one, both are merged as if with merge
. May throw Cannot_merge
if the path is incompatible with the original object (such as inserting in a field of something which is not an object) or if the value is to be merged with an incompatible existing value.
This function works with JSON data represented in the Json_repr.ezjsonm
format. See functor Make
for using another representation.
val replace :
path ->
Json_repr.ezjsonm ->
Json_repr.ezjsonm ->
Json_repr.ezjsonm
Same as insert
, except that if the path leads to a pre-existing value, it is replaced with the new one instead of being merged.
This function works with JSON data represented in the Json_repr.ezjsonm
format. See functor Make
for using another representation.
val merge : Json_repr.ezjsonm -> Json_repr.ezjsonm -> Json_repr.ezjsonm
Merges two compatible JSON values. Merges `Null
with any JSON value. Merges two deeply equal values together. Merges two objects by merging their common fields and adding all the others. Merges two arrays by merging their common cells pairwise and adding the remaining ones if one array is bigger than the other. May throw Cannot_merge
.
This function works with JSON data represented in the Json_repr.ezjsonm
format. See functor Make
for using another representation.
exception Cannot_merge of path
When two incompatible objects are unsuccessfully merged. Comes with the path to the first incompatibility encountered.
An path litteral could not be parsed. Comes with the original string, the position and an explanation.
exception Unsupported_path_item of path_item * string
An operation was given a path containing an unsupported construct. Comes with an explanation as its second argument.
val print_error :
?print_unknown:(Stdlib.Format.formatter -> exn -> unit) ->
Stdlib.Format.formatter ->
exn ->
unit
Produces a human readable version of an error.
module Make (Repr : Json_repr.Repr) : sig ... end