The Driver Class

The Driver class is abstract, and all Rexx Highlighter drivers should subclass it. It provides a common architecture for all highlighter drivers to follow, and it also centralizes a set of common services.

Conceptually, the output produced by a highlighter driver is composed of a prolog, a body and an epilog; the prolog and the epilog are specific to each driver. The body contains the driver-specific translations of every element in the source program.

new (Class method)

Returns a new instance of of the Driver class. Options. is a stem containing Highlighter options and internal values, and output is an array that will receive the highlighter output.

emit

Adds string to the current output line. Conceptually, it is equivalent to "CharOut ,string".

epilog (abstract method)

This is an abstract method, which should be defined by all subclasses of the Driver class.

prolog (abstract method)

This is an abstract method, which should be defined by all subclasses of the Driver class.

say

Adds string to the current output line, outputs the line, and starts a new one. Conceptually, it is equivalent to "Say string".

startLine

This method is called at the beginning of each line of code. It can be used, for example, to print line numbers.

tags2highlight

This is a utility method. Tags is a blank-separated set of HTML tags, and extra contains the highlighting information provided in the optional style patch. This method looks up the CSS highlightings defined by every tag in tags, combines them in order, and then applies the highlighting in extra, if any.

The returned value is a string with the following format

bold italic underline color"/"background

where bold, italic and underline are boolean values (that is, either 0 or 1), and color and background, which are both optional, use the #rrggbb CSS color format.