The type of fixed-width pretty-printers for values of type 'a. Specifically, these pretty-printers aim to emit strings that have the same rendered length in terminals (i.e. after accounting for UTF-8 encoding and ANSI escapes).

Most users don't need this module, and can use the pre-provided Line segments and Units printers directly.

int ~width pretty-prints integers using width characters, adding left padding if necessary. The printer will raise Invalid_argument if the integer to be printed can't be displayed in the given width.

string ~width is a pretty-printer for UTF8-encoded strings using width characters, adding right padding or truncating with ellipses as necessary.

For example, string ~width:8 processes values as follows:

  ""            ↦ "        "
  "hello"       ↦ "hello   "
  "hello world" ↦ "hello..."

Note: this printer uses a heuristic function (Uucp.tty_width_hint) to guess the rendered length of supplied strings. This function is not guaranteed to be correct on all UTF-8 codepoints, and so certain "unusual" string inputs can cause progress bar rendering to go awry.

using ~f t prints values v by passing f v to the printer t.

create ~to_string ~string_len () is a printer that uses to_string to render values in string_len-many bytes.

The rendered width of the output (when displayed in a terminal) is assumed to also be string_len (i.e. the output string is assumed to be ASCII), but this can be assumption can be overridden by passing an explicit ~width (e.g. if the printer emits non-ASCII UTF-8 characters or ANSI escape sequences).

Convert a pretty-printer to a Format-compatible pretty-printer.

Convert a pretty-printer to a to_string function.

print_width t is the number of terminal columns occupied by the output of t.