package yaml
Install
Dune Dependency
Authors
Maintainers
Sources
sha256=7f5bc9352b5d18671281986a72f74be29c9397a2411917ce3cbf5959888a4815
md5=97f4d85f56eb21fabc210b6ff009a771
doc/yaml/Yaml/index.html
Module Yaml
A library for parsing and emitting YAML.
It is based on a binding to libyaml which covers the generation and parsing processes.
Most simple use cases can simply use the of_string
and to_string
functions, which are compatible with the Ezjsonm
types. This means that you can convert between JSON and Yaml format easily.
If you use more advanced Yaml features such as aliases or anchors, then the yaml
type and yaml_of_string
and yaml_to_string
functions will be more useful. The library does not yet support expanding aliases into the JSON format from YAML, so that will currently result in an error.
Types
type value = [
| `Null
| `Bool of bool
| `Float of float
| `String of string
| `A of value list
| `O of (string * value) list
]
value
is the subset of a Yaml document that is compatible with JSON. This type is the same as Ezjsonm.value
, and so most simple uses of Yaml can be interchanged with JSON.
val sexp_of_value : value -> Ppx_sexp_conv_lib.Sexp.t
val value_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> value
val __value_of_sexp__ : Ppx_sexp_conv_lib.Sexp.t -> value
type yaml = [
| `String of anchor_string
| `Alias of string
| `A of yaml list
| `O of (anchor_string * yaml) list
]
yaml
is the representation of a Yaml document that preserves alias information and other Yaml-specific metadata that cannot be represented in JSON. It is not recommended to convert untrusted Yaml with aliases into JSON due to the risk of denial-of-service via a Billion Laughs attack.
yaml
is the representation of a Yaml document that preserves alias information and other Yaml-specific metadata that cannot be represented in JSON. It is not recommended to convert untrusted Yaml with aliases into JSON due to the risk of denial-of-service via a Billion Laughs attack.
anchor_string
holds a possible Yaml anchor, and the string value
val sexp_of_yaml : yaml -> Ppx_sexp_conv_lib.Sexp.t
val sexp_of_anchor_string : anchor_string -> Ppx_sexp_conv_lib.Sexp.t
val yaml_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> yaml
val __yaml_of_sexp__ : Ppx_sexp_conv_lib.Sexp.t -> yaml
val anchor_string_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> anchor_string
Version of the YAML spec of a document. Refer to the Yaml specification for details of the differences between versions.
val sexp_of_version : version -> Ppx_sexp_conv_lib.Sexp.t
val version_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> version
val __version_of_sexp__ : Ppx_sexp_conv_lib.Sexp.t -> version
Document encoding. The recommended format is Utf8
.
val sexp_of_encoding : encoding -> Ppx_sexp_conv_lib.Sexp.t
val encoding_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> encoding
val __encoding_of_sexp__ : Ppx_sexp_conv_lib.Sexp.t -> encoding
YAML provides three flow scalar styles: double-quoted, single-quoted and plain (unquoted). Each provides a different trade-off between readability and expressive power. The Yaml spec section 7.3 has more details.
val sexp_of_scalar_style : scalar_style -> Ppx_sexp_conv_lib.Sexp.t
val scalar_style_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> scalar_style
val __scalar_style_of_sexp__ : Ppx_sexp_conv_lib.Sexp.t -> scalar_style
Mappings and sequences can be rendered in two different ways:
Flow
styles can be thought of as the natural extension of JSON to cover folding long content lines for readability, tagging nodes to control construction of native data structures, and using anchors and aliases to reuse constructed object instances.Block
styles employ indentation rather than indicators to denote structure. This results in a more human readable (though less compact) notation.
val sexp_of_layout_style : layout_style -> Ppx_sexp_conv_lib.Sexp.t
val layout_style_of_sexp : Ppx_sexp_conv_lib.Sexp.t -> layout_style
val __layout_style_of_sexp__ : Ppx_sexp_conv_lib.Sexp.t -> layout_style
type 'a res = ('a, Rresult.R.msg) Result.result
This library uses the Rresult.R.msg
conventions for returning errors rather than raising exceptions.
Serialisers and deserialisers
Most simple uses of Yaml can use the JSON-compatible subset. If you really need Yaml-specific features such as aliases, then they are also available.
JSON-compatible functions
of_string s
parses s
into a JSON value
representation, discarding any Yaml-specific information such as anchors or tags.
val of_string_exn : string -> value
of_string_exn s
acts as of_string
, but raises Invalid_argument
if there is an error.
val to_string :
?len:int ->
?encoding:encoding ->
?scalar_style:scalar_style ->
?layout_style:layout_style ->
value ->
string res
to_string v
converts the JSON value to a Yaml string representation. The encoding
, scalar_style
and layout_style
control the various output parameters. The current implementation uses a non-resizable internal string buffer of 16KB, which can be increased via len
.
val to_string_exn :
?len:int ->
?encoding:encoding ->
?scalar_style:scalar_style ->
?layout_style:layout_style ->
value ->
string
to_string_exn v
acts as to_string
, but raises Invalid_argument
in if there is an error.
val pp : Format.formatter -> value -> unit
pp ppf s
will output the Yaml value s
to the formatter ppf
.
Yaml-specific functions
yaml_of_string s
parses s
into a Yaml yaml
representation, preserving Yaml-specific information such as anchors.
val yaml_to_string :
?encoding:encoding ->
?scalar_style:scalar_style ->
?layout_style:layout_style ->
yaml ->
string res
yaml_to_string v
converts the Yaml value to a string representation. The encoding
, scalar_style
and layout_style
control the various output parameters. The current implementation uses a non-resizable internal string buffer of 16KB, which can be increased via len
.
JSON/Yaml conversion functions
to_json yaml
will convert the Yaml document into a simpler JSON representation, discarding any anchors or tags from the original. Returns an error if any aliases are used within the body of the Yaml input.
of_json j
converts the JSON representation into a Yaml representation.
module Stream : sig ... end
Low-level event streaming interface for parsing and emitting YAML files.