# logtalk_load/2

## Description

    logtalk_load(File, Flags)
    logtalk_load(Files, Flags)

Compiles to disk and then loads to memory a source file or a list of source files using a list of compiler flags. The Logtalk source file name extension (by default, `.lgt`) can be omitted. Source file paths can be absolute, relative to the current directory, or use library notation. Compiler flags are represented as flag(value). This predicate can also be used to compile Prolog source files as Logtalk source code. When no recognized Logtalk or Prolog extension is specified, the compiler tries first to append a Logtalk source file extension and then a Prolog source file extension. If that fails, the compiler tries to use the file name as-is. For a description of the available compiler flags, please see the Compiler flags section in the User Manual. The recognized Logtalk and Prolog file extensions are defined in the backend adapter files. The recognized Logtalk and Prolog file extensions are defined in the backend adapter files.

When this predicate is called from the top-level interpreter, relative source file paths are resolved using the current working directory. When the calls are made from a source file, relative source file paths are resolved by default using the source file directory (unless a relative_to flag is passed).

Note that only the errors related to problems in the predicate argument are listed below. This predicate fails on the first error found during compilation of a source file. In this case, no contents of the source file are loaded.

Warning

The compiler flags specified in the second argument only apply to the files listed in the first argument and not to any files that those files may load or compile. Notably, if you are loading a loader file, the flags only apply to the loader file itself and not to the files loaded by it.

## Modes and number of proofs

    logtalk_load(@source_file_name, @list(compiler_flag)) - zero_or_one
    logtalk_load(@list(source_file_name), @list(compiler_flag)) - zero_or_one

## Errors

`File` is a variable:
`instantiation_error`
`Files` is a variable or a list with an element which is a variable:
`instantiation_error`
`File`, or an element `File` of the `Files` list, is neither a variable nor a source file name:
`type_error(source_file_name, File)`
`File`, or an element `File` of the `Files` list, uses library notation but the library does not exist:
`existence_error(library, Library)`
`File` or an element `File` of the `Files` list, does not exist:
`existence_error(file, File)`
`Flags` is a variable or a list with an element which is a variable:
`instantiation_error`
`Flags` is neither a variable nor a proper list:
`type_error(list, Flags)`
An element `Flag` of the `Flags` list is not a valid compiler flag:
`type_error(compiler_flag, Flag)`
An element `Flag` of the `Flags` list defines a value for a read-only compiler flag:
`permission_error(modify, flag, Flag)`
An element `Flag` of the `Flags` list defines an invalid value for a flag:
`domain_error(flag_value, Flag+Value)`

## Examples

    % compile and load the "list" source file in the
    % current directory using default compiler flags:
    | ?- logtalk_load(list, []).

    % compile and load the "tree" source file in the "types"
    % library directory with the source_data flag turned on:
    | ?- logtalk_load(types(tree)).

    % compile and load the "file_system" source file in the
    % current directory with portability warnings suppressed:
    | ?- logtalk_load(file_system, [portability(silent)]).

See also

logtalk_compile/1, logtalk_compile/2, logtalk_load/1, logtalk_make/0, logtalk_make/1, logtalk_library_path/2