Expressions.md

Expression Helpers

When writing long and complicated evaluated expressions, it can be easy to lose track of extra/missing perentheses, missing parameters, or unescaped commas. Especially when the whole expression has to be on one line without any linebreaks or whitespace.

The Expr class can help with this. If your expression is short enough this might be overkill, but for longer expressions this can really help with these issues. The named arguments aren't strictly necessary, but can help keep things more obviously in-line with the provided documentation which has been ported directly from the FFMpeg documentation.

note Currently only the eq, gt, if, and lt, have been implemented.

Example Diff

+ use ProjektGopher\FFMpegTools\Utils\Expr;

....

-   return "if(eq(({$time})\\,0)\\,0\\,if(eq(({$time})\\,1)\\,1\\,pow(2\\,-10*({$time}))*sin((({$time})*10-0.75)*{$c4})+1))";
+   return Expr::if(
+       x: Expr::eq($time, '0'),
+       y: '0',
+       z: Expr::if(
+           x: Expr::eq($time, '1'),
+           y: '1',
+           z: "pow(2\\,-10*({$time}))*sin((({$time})*10-0.75)*{$c4})+1",
+       ),
+   );