Module type `Changeset_lib.S`

Types

type source: The type of the original record type.

type 'a label: The type of the changeset labels corresponding to the fields defined in the type source .

type t: The type of changesets.

Exceptions

exception Invalid_changes of t: The exception raised when applying apply_exn on an invalid changeset.

Binding

type binding: The type of bindings used by the put_changes function.

val bind : 'a label ‑> 'a ‑> binding: bind l x returns a binding of l to x.

val (=>) : 'a label ‑> 'a ‑> binding: ( => ) is an infix operator for the bind function.

Errors

type error: The type of errors returned when a validation is not respected.

val error : 'a label ‑> Base.string ‑> error: error l s returns an error associating the label l to the error message s.

Changeset

val empty : t: The empty changeset.

val is_empty : t ‑> Base.bool: is_empty t returns true if the changes is empty, false otherwise.

val is_valid : t ‑> Base.bool: is_valid t returns true if the changeset t does not contain any error or false otherwise.

val from_record : source ‑> t: from_record x returns a changeset in which all the elements in x are loaded as changes.

val put_change : 'a label ‑> 'a ‑> t ‑> t: put_change l x t puts a change associating the label l with value x in the changeset t.

val put_changes : binding Base.list ‑> t ‑> t: put_change bs t applies put_change to the list of binding bs in the changeset t from left to right.

val put_error : error ‑> t ‑> t: put_error e t adds the error e in the changeset t.

val mem_label : _ label ‑> t ‑> Base.bool: mem_label l t returns true if there is a binding of l in the changeset t or false otherwise.

val mem_error : error ‑> t ‑> Base.bool: mem_error e t returns true if the error belongs to the changeset t or false otherwise.

val find : 'a label ‑> t ‑> 'a Base.option: find l t returns the value associated with the label l in the changeset t wrapped in an option value. It returns None if the label l is unbound in t.

val find_exn : 'a label ‑> t ‑> 'a: find l t returns the value associated with label l in the changeset t. It raises the exception Not_found if the label l is unbound in t.

val apply : t ‑> (source, t) Base.Result.t

apply t returns:

Ok x where x is a value of type source if the changeset t is valid and all the labels are present in the changes of t.
Error t' otherwise, where t' corresponds to the changeset t if it was not valid, or t expanded with an error (l => "is missing") if the changeset was valid but a label l was not found.

val apply_exn : t ‑> source: apply t returns a value of type source if the changeset t is valid and all the labels are present in the changes of t. It raises the exception Invalid_changes otherwise.

val show_errors : t ‑> Base.string: show_errors t returns a string in the json format of the errors contained in the changeset t.

Validations

val validate_change : 'a label ‑> ('a ‑> Base.string Base.list) ‑> t ‑> t: validate_change l f t applies f to the value associated with label l in the changeset t and adds the list of error messages returned to the errors of the changeset t, all being indexed by label l. If there is no binding for label l in changeset t, the validation is not applied.

val require : 'a label ‑> ?⁠message:Base.string ‑> t ‑> t: require l t validates that there is a binding of l in the changeset t. If not, the error message indexed by the label l is added to the changeset t. Default error message is "is required".

type length_opt = [ | `is of Base.int | `min of Base.int | `max of Base.int ]

Options for length validations are the ones above where:

`is n : the length must be exactly n.
`min n : the length must be greater than or equal to n.
`max n : the length must be less than or equal to n.

Error messages for validate_length, validate_array_length and validate_list_length are the following:

`is n : "should be %d element(s)"
`min n : "should be at least %d element(s)"
`max n : "should be at most %d element(s)"

Error messages for validate_string_length are the following:

`is n : "should be %d character(s)"
`min n : "should be at least %d character(s)"
`max n : "should be at most %d character(s)"

val validate_length : 'a label ‑> ('a ‑> Base.int) ‑> length_opt Base.list ‑> t ‑> t: validate_length l f opts t validates that the length calculated by applying f to the value indexed by the label l in the changeset t respects the opts.

val validate_string_length : Base.string label ‑> length_opt Base.list ‑> t ‑> t: validate_string_length l opts t validates that the length of the string indexed by the label l in the changeset t respects the opts.

val validate_array_length : 'a Base.array label ‑> length_opt Base.list ‑> t ‑> t: validate_array_length l opts t validates that the length of the array indexed by the label l in the changeset t respects the opts.

val validate_list_length : 'a Base.list label ‑> length_opt Base.list ‑> t ‑> t: validate_list_length l opts t validates that the length of the list indexed by the label l in the changeset t respects the opts.

type 'a ord_opt = [ | `equal_to of 'a | `greater_than of 'a | `greater_than_or_equal_to of 'a | `less_than of 'a | `less_than_or_equal_to of 'a ]

val validate : 'a label ‑> (module Base.Comparator.S with type t = 'a) ‑> 'a ord_opt Base.list ‑> t ‑> t: validate l cmp opts t validates that the value indexed by the label l in the changeset t respects the opts using the compare function provided by the first-class module cmp.

val validate_int : Base.int label ‑> Base.int ord_opt Base.list ‑> t ‑> t: validate_int l opts t validates that the integer indexed by label l in the changeset t respects the opts.

val validate_float : Base.float label ‑> Base.float ord_opt Base.list ‑> t ‑> t: validate_float l opts t validates that float indexed by label l in the changeset t respects the opts.

val validate_bool : Base.bool label ‑> Base.bool ord_opt Base.list ‑> t ‑> t: validate_bool l opts t validates that the boolean indexed by label l in the changeset t respects the opts.

val validate_char : Base.char label ‑> Base.char ord_opt Base.list ‑> t ‑> t: validate_char l opts t validates that the char indexed by label l in the changeset t respects the opts.

val validate_string : Base.string label ‑> Base.string ord_opt Base.list ‑> t ‑> t: validate_string l opts t validates that the string indexed by label l in the changeset t respects the opts.

val validate_inclusion : 'a label ‑> ('a ‑> 'a ‑> Base.bool) ‑> 'a Base.list ‑> ?⁠message:Base.string ‑> t ‑> t: validate_inclusion equal l xs ?message t validates that the value indexed by label l in the changeset t is a an included in xs. If not, an error message indexed by the label l is added to the changeset t. Default error message is "is invalid".

val validate_exclusion : 'a label ‑> ('a ‑> 'a ‑> Base.bool) ‑> 'a Base.list ‑> ?⁠message:Base.string ‑> t ‑> t: validate_excluded equal l xs ?message t validates that the value indexed by label l in the changeset t is not included in xs. If not, an error message indexed by the label l is added to the changeset t. Default error message is "is reserved".

val validate_acceptance : Base.bool label ‑> ?⁠message:Base.string ‑> t ‑> t: validate_string l ?message t validates that the change indexed by label l in the changeset t is true. If not, an error message indexed by the label l is added to the changeset t. Default error message is "must be accepted".

val validate_format : Base.string label ‑> Str.regexp ‑> ?⁠message:Base.string ‑> t ‑> t: validate_format l reg ?message t validates that the change indexed by label l in the changeset t is accepted by the regex r. If not, an error message indexed by the label l is added to the changeset t. Default error message is "has invalid format".