Module Delimited_parsing.Csv

Csv parses character-separated values where fields may be quoted and quotation marks within quoted fields are escaped with another quotation mark, MSExcel-style.

An applicative interface for parsing values from a csv file.

module Header = Header
type 'a t

This provides an applicative interface for constructing values from a csv file.

An 'a t describes how to build an OCaml model 'a for each row.

See lib/async_extended/example/csv_example.ml for an example of usage.

include Core.Applicative.S with type a t := a t
type 'a t
val return : 'a ‑> 'a t
val apply : ('a ‑> 'b) t ‑> 'a t ‑> 'b t
val map : 'a t ‑> f:('a ‑> 'b) ‑> 'b t
val map2 : 'a t ‑> 'b t ‑> f:('a ‑> 'b ‑> 'c) ‑> 'c t
val map3 : 'a t ‑> 'b t ‑> 'c t ‑> f:('a ‑> 'b ‑> 'c ‑> 'd) ‑> 'd t
val all : 'a t list ‑> 'a list t
val all_unit : unit t list ‑> unit t
val all_ignore : unit t list ‑> unit t
  • Deprecated [since 2018-02] Use [all_unit]
val both : 'a t ‑> 'b t ‑> ('a * 'b) t
module Applicative_infix : sig ... end
include module type of Applicative_infix
val (<*>) : ('a ‑> 'b) t ‑> 'a t ‑> 'b t

same as apply

val (<*) : 'a t ‑> unit t ‑> 'a t
val (*>) : unit t ‑> 'a t ‑> 'a t
module Let_syntax : sig ... end
val at_index : int ‑> f:(string ‑> 'a) ‑> 'a t
val at_header : string ‑> f:(string ‑> 'a) ‑> 'a t
type 'a on_invalid_row

'a on_invalid_row specifies how to handle a row whose extents are known but whose contents cannot be converted to a value of type 'a. The default is to raise.

If a row's extents are unknown, the parser cannot continue and will always raise.

val fold_reader : ?⁠strip:bool ‑> ?⁠skip_lines:int ‑> ?⁠sep:char ‑> ?⁠quote:[ `No_quoting | `Using of char ] ‑> ?⁠header:Header.t ‑> ?⁠on_invalid_row:'a on_invalid_row ‑> 'a t ‑> init:'b ‑> f:('b ‑> 'a ‑> 'b Async.Deferred.t) ‑> Async.Reader.t ‑> 'b Async.Deferred.t

of_reader ?strip ?skip_lines ?sep ?quote ~init ~f r produces a value by folding over a csv document read from r.

If strip is true, leading and trailing whitespace is stripped from each field. Default value is false.

If skip_lines > 0, that many lines are skipped at the start of the input. Note that this skips lines without doing any CSV parsing of the lines being skipped, so newlines within a quoted field are treated identically to newlines outside a quoted field. Default value is 0.

sep is the character that separates fields within a row. Default value is ','

quote defines a character to use for quoting. The default is `Using '"' which implements the MS Excel convention: either a field is unquoted, or it has leading and trailing quotes and internal escaped characters are represented as quote-char char, e.g., {|"a|} for a. `No_quoting means all characters are literal.

val fold_reader' : ?⁠strip:bool ‑> ?⁠skip_lines:int ‑> ?⁠sep:char ‑> ?⁠quote:[ `No_quoting | `Using of char ] ‑> ?⁠header:Header.t ‑> ?⁠on_invalid_row:'a on_invalid_row ‑> 'a t ‑> init:'b ‑> f:('b ‑> 'a Core.Queue.t ‑> 'b Async.Deferred.t) ‑> Async.Reader.t ‑> 'b Async.Deferred.t

of_reader' ?strip ?skip_lines ?sep ?quote ~init ~f r works similarly to of_reader, except for the f argument. of_reader' runs f on batches of Row.ts rather than running f on each individual row.

val fold_reader_without_pushback : ?⁠strip:bool ‑> ?⁠skip_lines:int ‑> ?⁠sep:char ‑> ?⁠quote:[ `No_quoting | `Using of char ] ‑> ?⁠header:Header.t ‑> ?⁠on_invalid_row:'a on_invalid_row ‑> 'a t ‑> init:'b ‑> f:('b ‑> 'a ‑> 'b) ‑> Async.Reader.t ‑> 'b Async.Deferred.t
val fold_reader_to_pipe : ?⁠strip:bool ‑> ?⁠skip_lines:int ‑> ?⁠sep:char ‑> ?⁠quote:[ `No_quoting | `Using of char ] ‑> ?⁠header:Header.t ‑> ?⁠on_invalid_row:'a on_invalid_row ‑> 'a t ‑> Async.Reader.t ‑> 'a Async.Pipe.Reader.t
val fold_string : ?⁠strip:bool ‑> ?⁠sep:char ‑> ?⁠quote:[ `No_quoting | `Using of char ] ‑> ?⁠header:Header.t ‑> ?⁠on_invalid_row:'a on_invalid_row ‑> 'a t ‑> init:'b ‑> f:('b ‑> 'a ‑> 'b) ‑> string ‑> 'b

Low-level interface

module Fast_queue : sig ... end
module On_invalid_row : sig ... end
module Parse_state : sig ... end

Backwards-compatible interface

module Builder : sig ... end
val create_parse_state : ?⁠strip:bool ‑> ?⁠sep:char ‑> ?⁠quote:[ `No_quoting | `Using of char ] ‑> ?⁠on_invalid_row:'a on_invalid_row ‑> header_map:int Core.String.Map.t ‑> 'a t ‑> init:'b ‑> f:('b ‑> 'a ‑> 'b) ‑> 'b Parse_state.t
module Header_parse : sig ... end
module Row : sig ... end
exception Bad_csv_formatting of string list * string