If you are outputting to a terminal, you may want to control the positioning of the cursor:
at-xy ( x y – ) facility “at-x-y”
Put the curser at position x y
at-deltaxy ( dx dy – ) gforth-0.7 “at-deltaxy”
With the current position at x y, put the cursor at x+dx y+dy.
In order to know where to position the cursor, it is often helpful to know the size of the screen:
form ( – nlines ncols ) gforth-0.2 “form”
And sometimes you want to use:
page ( – ) facility “page”
Clear the screen
Note that on non-terminals you should use 12 emit, not
page, to get a form feed.
The following words are used to create (semantic) colorful output; further output is produced in the color and style given by the word; the actual color and style depends on the theme (see below).
default-color ( – ) gforth-1.0 “default-color”
use system-default color
error-color ( – ) gforth-1.0 “error-color”
error color: red
error-hl-inv ( – ) gforth-1.0 “error-hl-inv”
color mod for error highlight inverse
error-hl-ul ( – ) gforth-1.0 “error-hl-ul”
color mod for error highlight underline
warning-color ( – ) gforth-1.0 “warning-color”
color for warnings: blue/yellow on black terminals
info-color ( – ) gforth-1.0 “info-color”
color for info: green/cyan on black terminals
success-color ( – ) gforth-1.0 “success-color”
color for success: green
input-color ( – ) gforth-1.0 “input-color”
color for user-input: black/white (both bold)
status-color ( – ) gforth-1.0 “status-color”
color mod for error highlight inverse
Depending on wether you prefer bright or dark background the foreground colors-theme can be changed by:
light-mode ( – ) gforth-1.0 “light-mode”
color theme for white background
dark-mode ( – ) gforth-1.0 “dark-mode”
color theme for black background