Consoleprelude
module Console
ANSI terminal styling: colors, text attributes, and cursor control.
Every constant here becomes an empty string when Kex is started with --no-colors, or when output is not going to a terminal. You can splice them into a string unconditionally.
colorize is usually what you want, since it applies the reset for you.
constant RESET ?
Clears every active style. Ends a styled run started with a color or attribute constant; colorize appends it for you.
constant BOLD ?
Renders following text in bold.
constant DIM ?
Renders following text dimmed. Useful for secondary detail that should not compete with the main output.
constant ITALIC ?
Renders following text in italics, where the terminal supports it.
constant UNDERLINE ?
Underlines following text.
constant BLINK ?
Makes following text blink, where the terminal supports it. Most do not, and most users would rather they did not.
constant REVERSE ?
Swaps the foreground and background colors of following text.
constant STRIKETHROUGH ?
Strikes through following text.
constant RED ?
Red. Conventionally: errors and failures.
constant GREEN ?
Green. Conventionally: success.
constant YELLOW ?
Yellow. Conventionally: warnings.
constant BLUE ?
Blue. Useful for informational labels and links.
constant MAGENTA ?
Magenta. Useful for highlighting a category distinct from status colors.
constant CYAN ?
Cyan. Useful for identifiers, paths, and other values inside prose.
constant WHITE ?
White. Useful for primary text on a dark terminal.
constant GRAY ?
Gray. Conventionally: de-emphasised detail, like DIM but as a color.
constant PURPLE ?
Purple. An alternative accent when magenta is already in use.
constant CLEAR ?
Erases the screen and moves the cursor to the top-left corner.
Use it to start a fresh frame. When you are redrawing repeatedly, HOME gives a smoother result: see below.
constant HOME ?
Moves the cursor to the top-left corner without erasing anything.
A redraw that starts here paints over the previous frame, so there is no blank flash between frames the way CLEAR produces.
constant CLEARLINE ?
Erases the current line and returns the cursor to its start.
This is how to write a progress line in place rather than one line per update.
function colorize
Wraps text in color and appends a reset, so the style ends where the text does.
Preferred over splicing the constants by hand: it cannot leak a style into the rest of the line, and it still produces plain text when color is off.
colorize(text, color) : String -> String -> StringParameters
textString- the text to style
colorString- a style constant from this module
Returns: String — the styled text
Examples
Console.colorize("ok", Console.GREEN)
Console.colorize("error", Console.RED)Styling a status word inside a longer line
IO.printLine("build ${Console.colorize("passed", Console.GREEN)} in 2.1s")constant enabled? Bool
Returns true when terminal styling is on for this process.
It is false under --no-colors and when output is redirected. You rarely need to check it (the constants already collapse to "") but it is the right test when the alternative is a different layout rather than a different color.