The microtype package

IMPLEMENTATION: Configuration 1113440 3441 \def\MT@warn@nodim#1{%3442 \MT@warning{`\@tempa’ is not a dimension.\MessageBreak3443 Ignoring it and setting values relative to\MessageBreak #1}%3444 }3445 Protrusion codes may be relative to character width, or to any dimension.3446 3447 \define@key{MT@pr@c}{unit}[character]{%3448 \MT@glet@nc{MT@pr@c@\MT@curr@set@name @unit}\@empty3449 \def\@tempa{#1}%3450 \MT@ifstreq\@tempa{character}\relax{%Test whether it’s a dimension, but do not translate it into its final form here, sinceit may be font-specific.3451 \MT@ifdimen\@tempa3452 {\MT@glet@nc{MT@pr@c@\MT@curr@set@name @unit}\@tempa}%3453 {\MT@warn@nodim{character widths}}%3454 }%3455 }3456 Tracking may only be relative to a dimension.3457 3458 \define@key{MT@tr@c}{unit}[1em]{%3459 \MT@glet@nc{MT@tr@c@\MT@curr@set@name @unit}\@empty3460 \def\@tempa{#1}%3461 \MT@ifdimen\@tempa3462 {\MT@glet@nc{MT@tr@c@\MT@curr@set@name @unit}\@tempa}%3463 {\MT@warn@nodim{1em}%3464 \MT@gdef@n{MT@tr@c@\MT@curr@set@name @unit}{1em}}%3465 }3466 Spacing and kerning codes may additionally be relative to space dimensions.3467 3468 \MT@map@clist@n{sp,kn}{%3469 \define@key{MT@#1@c}{unit}[space]{%3470 \MT@glet@nc{MT@#1@c@\MT@curr@set@name @unit}\@empty3471 \def\@tempa{##1}%3472 \MT@ifstreq\@tempa{character}\relax{%3473 \MT@glet@nc{MT@#1@c@\MT@curr@set@name @unit}\m@ne3474 \MT@ifstreq\@tempa{space}\relax{%3475 \MT@ifdimen\@tempa3476 {\MT@glet@nc{MT@#1@c@\MT@curr@set@name @unit}\@tempa}%3477 {\MT@warn@nodim{width of space}}%3478 }%3479 }%3480 }%3481 }3482 The first argument to \SetExpansion accepts some more options.3483 3484 \MT@map@clist@n{stretch,shrink,step}{%3485 \define@key{MT@ex@c}{#1}[]{%3486 \MT@ifempty{##1}\relax{%3487 \MT@ifint{##1}{%A space terminates the number.3488 \MT@gdef@n{MT@ex@c@\MT@curr@set@name @#1}{##1 }%3489 }{%3490 \MT@warning{%3491 Value `##1’ for option `#1’ is not a number.\MessageBreak