Strings

((draw-string viewport) p string color)
draw-string takes a viewport descriptor. It returns a function that draws a string at a specified location in the viewport. The lower left of the string begins at p. The optional color argument defaults to black.

((clear-string viewport) p string)
clear-string takes a viewport descriptor. It returns a function that clears a string at a specified location in viewport. The lower left of the string begins at p.

((flip-string viewport) p string)
flip-string takes a viewport descriptor. It returns a function that flips a string at a specified location in viewport. The lower left of the string begins at p.