The microtype package

IMPLEMENTATION: Package options 122\MT@config@file\MT@get@config\MT@check@active@setThe main configuration file will be loaded before processing the package options.However, the config option must of course be evaluated beforehand. We also haveto define a no-op for the regular option processing later.3962 3963 \define@key{MT}{config}[]{\relax}3964 \def\MT@get@config#1config=#2,#3\@nil{%3965 \MT@ifempty{#2}%3966 {\def\MT@config@file{\MT@MT.cfg}}%3967 {\def\MT@config@file{#2.cfg}}%3968 }3969 \expandafter\expandafter\expandafter\MT@get@config3970 \csname opt@\@currname.\@currext\endcsname,config=,\@nilLoad the file.3971 \IfFileExists{\MT@config@file}{%3972 \MT@info@nl{Loading configuration file \MT@config@file}%3973 \MT@begin@catcodes3974 \let\MT@begin@catcodes\relax3975 \let\MT@end@catcodes\relax3976 \let\MT@curr@file\MT@config@file3977 \input{\MT@config@file}%3978 \endgroup3979 }{\MT@warning@nl{%3980 Could not find configuration file `\MT@config@file’!\MessageBreak3981 This will almost certainly cause undesired results.\MessageBreak3982 Please fix your installation}%3983 }We have to make sure that font sets are active. If the user didn’t activate any, weuse those sets declared by \DeclareMicrotypeSetDefault (this is done at the endof the preamble).3984 \def\MT@check@active@set#1{%3985 \MT@ifdefined@n@TF{MT@#1@setname}{%3986 \MT@info@nl{Using \@nameuse{MT@abbr@#1} set `\@nameuse{MT@#1@setname}’}%3987 }{%3988 \MT@ifdefined@n@TF{MT@default@#1@set}{%3989 \MT@glet@nn{MT@#1@setname}{MT@default@#1@set}%3990 \MT@info@nl{Using default \@nameuse{MT@abbr@#1} set `\@nameuse{MT@#1@setname}’}%3991 }{%If no default font set has been declared in the main configuration file, we use the(empty, non-existent) set ‘@’, and issue a warning.3992 \MT@gdef@n{MT@#1@setname}{@}%3993 \MT@warning@nl{No \@nameuse{MT@abbr@#1} set chosen, no default set declared.3994 \MessageBreak Using empty set}%3995 }%3996 }%3997 }14.4.4 Hook for other packages\Microtype@HookThis hook may be used by font package authors, e.g., to declare alias fonts. If itis defined, it will be executed here, i.e., after the main configuration file has beenloaded, and before the package options are evaluated.This hook was needed in versions prior to 1.9a to overcome the situation that(1) the microtype package should be loaded after all font defaults have been setup (hence, using \@ifpackageloaded in the font package was not viable), and(2) checking \AtBeginDocument could be too late, since fonts might already havebeen loaded, and consequently set up, in the preamble. With the new deferredsetup, one could live without this command, however, it remains here since it’s