Logtalk reference manual
Built-in predicate: logtalk_load_context/2
Contents > Reference Manual > Built-in Predicates > logtalk_load_context/2

## logtalk_load_context/2

#### Description

    logtalk_load_context(Key, Value)

Provides access to the Logtalk compilation/loading context. The following keys are currently supported: `entity_identifier`, `entity_prefix`, `entity_type` (returns the value `module` when compiling a module as an object), `source`, `file` (the actual file being compiled, which is different from `source` only when processing an `include/1` directive), `basename`, `directory`, `stream`, `target` (the full path of the intermediate Prolog file), `flags` (the list of the explicit flags used for the compilation of the source file), `term` (the term being expanded), `term_position` (`StartLine-EndLine`), and `variable_names` (`[Name1=Variable1, ...]`). The `term_position` key is only supported in back-end Prolog compilers that provide access to the start and end lines of a read term.

The `logtalk_load_context/2` predicate can also be called `initialization/1` directives in a source file. A common scenario is to use the `directory` key to define library aliases.

Currently, any variables in the values of the `term` and `variable_names` keys are not shared with, respectively, the term and goal arguments of the `term_expansion/2` and `goal_expansion/2` methods.

Using the `variable_names` key requires calling the standard built-in predicate `term_variables/2` on the term read and unifying the term variables with the variables in the names list. This, however, may rise portability issues with those Prolog compilers that don't return the variables in the same order for the `term_variables/2` predicate and the option `variable_names/1` of the `read_term/3` built-in predicate, which is used by the Logtalk compiler to read source files.

#### Template and modes

    logtalk_load_context(?atom, -nonvar)

#### Errors

`(none)`

#### Examples

    term_expansion(Term, ExpandedTerms) :-
        ...
        logtalk_load_context(entity_identifier, Entity),
        ....

    :- initialization((
        logtalk_load_context(directory, Directory),
        assertz(logtalk_library_path(my_app, Directory))
    )).

#### See also

`goal_expansion/2`, `term_expansion/2`