prolog_colour.pl -- Prolog syntax colouring support.

This module defines reusable code to colourise Prolog source.

To be done

- : The one-term version

 prolog_colourise_stream(+Stream, +SourceID, :ColourItem) is det

 prolog_colourise_stream(+Stream, +SourceID, :ColourItem, +Opts) is det

Determine colour fragments for the data on Stream. SourceID is the canonical identifier of the input as known to the cross-referencer, i.e., as created using xref_source(SourceID).

ColourItem is a closure that is called for each identified fragment with three additional arguments:

• The syntactical category
• Start position (character offset) of the fragment
• Length of the fragment (in characters).

Options

operators(+Ops)

Provide an initial list of additional operators.

 prolog_colourise_query(+Query:string, +SourceId, :ColourItem)

Colourise a query, to be executed in the context of SourceId.

Arguments:

SourceId

- Execute Query in the context of the cross-referenced environment SourceID.

 prolog_colourise_term(+Stream, +SourceID, :ColourItem, +Options)

Colourise the next term on Stream. Unlike prolog_colourise_stream/3, this predicate assumes it is reading a single term rather than the entire stream. This implies that it cannot adjust syntax according to directives that precede it.

Options:

subterm_positions(-TermPos)

Return complete term-layout. If an error is read, this is a term error_position(StartClause, EndClause, ErrorPos)

current_variable(+VarName)

Variable to highlight

 vararg_goal_classification(+Name, +Arity, -Class) is semidet[multifile]

Multifile hookable classification for vararg predicates.

 syntax_colour(?Class, ?Attributes) is nondet

True when a range classified Class must be coloured using Attributes. Attributes is a list of:

• colour(ColourName)
• background(ColourName)
• bold(Boolean)
• underline(Boolean)

Attributes may be the empty list. This is used for cases where -for example- a menu is associated with the fragment. If syntax_colour/2 fails, no fragment is created for the region.

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 syntax_message(Arg1, Arg2, Arg3)