Highlighters

A highlighter is an instance of the structure Highlighter that contains information about which elements a highlight style should be applied. The structure contains three fields:

f: Function with the signature f(data,i,j) in which should return true if the element (i,j) in data must be highlighted, or false otherwise.
crayon: Crayon with the style of a highlighted element.

The function f must have the following signature:

f(data, i, j)

in which data is a reference to the data that is being printed, i and j are the element coordinates that are being tested. If this function returns true, then the highlight style will be applied to the (i,j) element. Otherwise, the default style will be used.

A set of highlighters can be passed as a Tuple to the highlighter keyword. Notice that if multiple highlighters are valid for the element (i,j), then the applied style will be equal to the first match considering the order in the Tuple highlighters.

Note

If the highlighters are used together with Formatter, then the change in the format will not affect that parameter data passed to the highlighter function f. It will always receive the original, unformatted value.

There are a set of pre-defined highlighters (with names hl_*) to make the usage simpler. They are defined in the file ./src/predefined_highlighters.jl.

To make the syntax less cumbersome, the following helper function is available:

    function Highlighter(f; kwargs...)

It creates a Highlighter with the function f and pass all the keyword arguments kwargs to the Crayon. Hence, the following code:

julia> Highlighter((data,i,j)->isodd(i), Crayon(bold = true, background = :dark_gray))

can be replaced by:

julia> Highlighter((data,i,j)->isodd(i); bold = true, background = :dark_gray)