Module Logs.TagSource

Message tags.

Message tags are arbitrary named and typed values that can be associated to log messages. See an example.

Tag definitions

Sourcetype 'a def

The type for tag definitions. The type 'a is the type of the tag. The definition specifies a name for the tag, a pretty-printer for the type of the tag and a documentation string. See def.

Sourcetype def_e =
  1. | Def : 'a def -> def_e

The type for existential tag definitions.

Sourceval def : ?doc:string -> string -> (Format.formatter -> 'a -> unit) -> 'a def

def ~doc name pp is a tag definition. name is the name of the tag, it doesn't need to be unique. pp is a printer for the type of the tag. doc is a documentation string describing the tag (defaults to "undocumented").

Sourceval name : 'a def -> string

name d is d's name.

Sourceval doc : 'a def -> string

doc d is d's documentation string.

Sourceval printer : 'a def -> Format.formatter -> 'a -> unit

printer d is d's type pretty-printer.

Sourceval pp_def : Format.formatter -> 'a def -> unit

pp_def ppf d prints an unspecified representation of d on ppf.

Sourceval list : unit -> def_e list

tag_list () is the list of currently existing tag definitions.

Tags

Sourcetype t =
  1. | V : 'a def * 'a -> t

The type for tags. Tuples the tag definition and its value.

Sourceval pp : Format.formatter -> t -> unit

pp ppf t prints an unspecified representation of t on ppf.

Tag sets

Sourcetype set

The type for tag sets. A tag set contains at most one tag per tag definition.

Sourceval empty : set

empty is the empty set.

Sourceval is_empty : set -> bool

is_empty s is true iff s is empty.

Sourceval mem : 'a def -> set -> bool

mem d s is true iff s has a tag with definition d.

Sourceval add : 'a def -> 'a -> set -> set

add d v s is s with the tag (V (d, v)) added. If there was a tag with definition d in s it is replaced.

Sourceval rem : 'a def -> set -> set

rem d s is s without the tag defined by d (if there was one).

Sourceval find : 'a def -> set -> 'a option

find d s is the tag value with definition d in s (if any).

Sourceval get : 'a def -> set -> 'a

get d s is like find d s but

Sourceval fold : (t -> 'a -> 'a) -> set -> 'a -> 'a

fold f s acc is the result of folding f over the tags of s starting with acc.

Sourceval pp_set : Format.formatter -> set -> unit

pp_set ppf s prints an unspecified representation of s on ppf.