how to indent a block of code

how to indent a block of code one space or four spaces by code?i know gsub?is there any other simple way?
another question?it shows?shader compile error?attempt to redeclare ‘step’ as variable?attempt to use ‘step’ as variable… how to make it?

Perhaps you have already used ‘step’ as a uniform or varying, and cannot change it. Use a different variable name.

Post code if you want us to figure out the problem.

thanks?its the former post’s code?http://codea.io/talk/discussion/6772/multiple-step-colour-gradient-shader#latest

you will have to write a message to the person who posted the code, I suggest