utf8 is the style used by bar ~style:`UTF8. Uses the UTF-8 block element characters (U+2588–U+258F) for progress stages, and a box-drawing character (U+2502) for delimiters.
Custom styles
val v :
?delims:(string * string)->?color:Color.t->?color_empty:Color.t->string list->t
v stages is a bar that uses the given string stages to render progress. The first stage is interpreted as a "full" segment, with subsequent stages denoting progressively less-full segments until a final "empty" stage (which is implicitly a space if only one stage is provided).
The optional parameters are as follows:
?delims: a pair of left and right delimiters used to wrap the body of the progress bar;
?color: the color of non-empty segments (including the in-progress one);
?color_empty: the color of empty segments.
Examples
v [ "#" ] renders like "####### ";
v [ "="; ">"; " " ] renders like "======> ";
v [ "4"; "3"; "2"; "1"; "0" ] renders like "444444410000";
... see examples/bar_styles.ml in the source repository for more.
Specifics
Each segment of a rendering progress bar is in one of three states: full, empty or in-progress. At any given time, either the bar is entirely full or or there is exactly one in-progress segment. Given the style v [s1; s2; ... sN], these states are rendered as follows:
full: rendered as s1;
empty: rendered as sN if N >= 1, otherwise ' ';
in-progress: if N <= 1, then equivalent to the empty state. Otherwise, the intermediate stages s2, s3, ... s{N-1} denote decreasing progress. For example, if there are four intermediate stages (N = 6) then s2 is used for progress in the range [0, 25%), s3 for [25%, 50%) etc.
For the progress bar to render within a fixed size, the user must ensure that each of the stages must have the same rendered width.