in p5.js your code is a
sketch.js
file,
in Processing IDE JAVA Mode your code is in a
mySketch.pde
file
both are ASCII and editable by many editors.
insofar i question your wording you IMPORT something.
but possibly you want to talk about the project handling by IDE’s
other than Processing 3.5.3
also: this is a forum about Processing language AND Processing IDE
so the support of other IDE will be limited ( might be better to ask at their forum )
but you can get lucky to find someone here who is using the same tool like you
so i wonder why you ?avoid? naming the
you are now used to.
also please be aware that other tools/editors might have some NICE things
- code folding
- code block coloring
what currently are not available with processing IDE
you can expect that they will have disadvantages like reduced support
- help
- examples
- libraries management
- error handling
- project management / save as / archive /
so:
please start with the Processing IDE now
and in 2 month, when you know that IDE ( and Processing JAVA ) better,
you can start again with working via a external IDE.