package asai

  1. Overview
  2. Docs

This module provides functions to display or interact with diagnostics in UNIX terminals.



val display : ?output:Stdlib.out_channel -> ?use_ansi:bool -> ?use_color:bool -> ?show_backtrace:bool -> ?line_breaking:[ `Unicode | `Traditional ] -> ?block_splitting_threshold:int -> ?tab_size:int -> Message.t Diagnostic.t -> unit

display d prints the diagnostic d to the standard output, using terminal control characters for formatting. A message will look like this (but with coloring):

 → warning[hello]
 ╭ ■ /path/to/
 ┆ 1 | aaaaaaaaaa
 ┆ 2 | bbbbbbbbbb
 ╯   ^ when stepping into the abyss
 ■ /path/to/
 2 | bbbbbbbbbb
 3 | cccccccccc
   ^ could not say hi here
  • parameter output

    The output channel, such as stdout or stderr. By default, it is stdout, the standard output.

  • parameter use_ansi

    Whether ANSI escape sequences should be used, overwriting the auto-detection. By default, the auto-detection checks whether the output is a TTY and whether the environment variable TERM is set to a non-empty value other than dumb. Note that this handler is currently using exclusively ANSI escape sequences for highlighting, which means turning them off will lose the precise location. (This may change in the future.)

  • parameter use_color

    Whether colors should be use when ANSI escape sequences are used, overwriting the auto-detection. By default, the auto-detection will turn off the colors if a non-empty value was assigned to the environment variable NO_COLOR. Note that even when the colors are turned off, the handler may still use the bold style, the faint style, and underlines for highlighting. This parameter has no effects if ANSI escape sequences are not used.

  • parameter show_backtrace

    Whether the backtrace should be shown. The default is true.

  • parameter line_breaking

    The algorithm to recognize (hard) line breaks. The `Unicode algorithm recognizes all Unicode character sequences in Unicode 15.0.0 Table 5-1 as line breaks. The `Traditional algorithm only recognizes U+000A (LF), U+000D (CR), and U+000D U+000A (CRLF) as line breaks. The default is the `Traditional algorithm.

  • parameter block_splitting_threshold

    The maximum number of consecutive, non-highlighted lines allowed in a block. The function will try to minimize the number of blocks, as long as no block has too many consecutive, non-highlighted lines. A higher threshold will lead to fewer blocks. When the threshold is zero, it means no block can contain any non-highlighted line. The default value is 5.

  • parameter tab_size

    The number of spaces that should be used to replace a horizontal tab. Note that a horizontal tab is always expanded to the same number of spaces. The result should still be visually appealing as long as horizontal tabs are only used at the beginning of lines. The default value is 8.

  • raises Invalid_argument

    if tab_size < 0.


Innovation. Community. Security.