csvfields

Runtime support for ppx_xml_conv and ppx_csv_conv
IN THIS PACKAGE
Module Csvlib . Csv
type t = string list list

Representation of CSV files.

exception Bad_CSV_file of string

Badly formed CSV files throw this exception.

val lines : t -> int

Work out the number of lines in a CSV file.

val columns : t -> int

Work out the (maximum) number of columns in a CSV file. Note that each * line may be a different length, so this finds the one with the most * columns.

val load_in : ?separator:char -> in_channel -> t

Load a CSV file. *

  • parameter chan

    Input file stream

val load : ?separator:char -> string -> t

Load a CSV file. *

  • parameter filename

    CSV filename.

val load_string : ?separator:char -> string -> t

Load a CSV from a string. *

  • parameter s

    String whose contents is the entire CSV.

val load_rows : ?separator:char -> ( string list -> unit ) -> in_channel -> unit

For very large CSV files which cannot be processed in memory at once, * this function is appropriate. It parses the input one row at a time and * calls your function once for each row. * * Note that if you CSV file contains cells which have embedded * line feeds, then it is non-trivial to parse these lines and * pass them correctly to load_rows. * *

  • parameter f

    Callout function. *

    @param chan

    Input file stream.

val load_rows_inchar : ?separator:char -> ( string list -> unit ) -> ( unit -> char ) -> unit

Works exactly like load_rows except that instead of reading from * a descriptor, it calls a read_char function. This function * throws End_of_file on the end of input.

val trim : ?top:bool -> ?left:bool -> ?right:bool -> ?bottom:bool -> t -> t

This takes a CSV file and trims empty cells. * * All four of the option arguments (~top, ~left, ~right, ~bottom) * default to true. * * The exact behaviour is: * * ~right: If true, remove any empty cells at the right hand end of * any row. The number of columns in the resulting CSV structure will * not necessarily be the same for each row. * * ~top: If true, remove any empty rows (no cells, or containing just empty * cells) from the top of the CSV structure. * * ~bottom: If true, remove any empty rows from the bottom of the * CSV structure. * * ~left: If true, remove any empty columns from the left of the * CSV structure. Note that ~left and ~right are quite different: * ~left considers the whole CSV structure, whereas ~right considers * each row in isolation.

val square : t -> t

Make the CSV data "square" (actually rectangular). This pads out * each row with empty cells so that all rows are the same length as * the longest row. After this operation, every row will have length * columns.

val associate : string list -> t -> (string * string) list list

associate header data takes a block of data and converts each * row in turn into an assoc list which maps column header to data cell. * * Typically a spreadsheet will have the format: *

  *   header1   header2   header3
  *   data11    data12    data13
  *   data21    data22    data23
  *     ...
  *

* * This function arranges the data into a more usable form which is * robust against changes in column ordering. The output of the * function is: *

  *   [ ["header1", "data11"; "header2", "data12"; "header3", "data13"];
  *     ["header1", "data21"; "header2", "data22"; "header3", "data23"];
  *     etc. ]
  *

* * Each row is turned into an assoc list (see List.assoc). * * If a row is too short, it is padded with empty cells (""). If * a row is too long, it is truncated. * * You would typically call this function as: * *

  * let header, data = match csv with h :: d -> h, d | [] -> assert false;;
  * let data = Csv.associate header data;;
  *

* * The header strings are shared, so the actual space in memory consumed * by the spreadsheet is not much larger.

val print : ?separator:char -> t -> unit

Print string list list - same as save_out stdout

val save_fn : ?separator:char -> ( string -> unit ) -> t -> unit

Save the string list list, writing the strings by calling the given * given functon.

val save_out : ?separator:char -> out_channel -> t -> unit

Save string list list to a channel.

val save : ?separator:char -> string -> t -> unit

Save string list list to a file.

val print_readable : t -> unit

Print the CSV data to stdout in a human-readable format. Not much * is guaranteed about how the CSV is printed, except that it will be * easier to follow than a "raw" output done with print. This is * a one-way operation. There is no easy way to parse the output of * this command back into CSV data.

val save_out_readable : out_channel -> t -> unit

As for print_readable, allowing the output to be sent to a channel.

val save_fn_readable : ( string -> unit ) -> t -> unit