Comparing Import and With - caffeine-suite/caffeine-script GitHub Wiki

JavaScript's with

My concept of import is similar to JavaScript's built-in with. I know with is maligned, but I think with can be rehabilitated with slightly different semantics:

• CaffeineScript's import is resolved be implemented as a load-time cost, not a runtime cost. Essentially, there should be little or no practical performance hit. If needed, it could potentially be computed at compile-time.

Pros, cons, thoughts:

• Since you can always view the generated javascript, CaffeineScript's import should be easier to understand.
• import best practices
  • import should only be used at load time
  • import should only be used with plain objects

import vs with

• arguments against with
• Most of these 'bad' examples are just bad uses of with. As with all powerful tools, including most programming constructs, you can shoot yourself in your foot if you use them incorrectly.
• Not-future-proof is the most interesting example in the link above.
  • Even if you use the import best-practices from above you could still be susceptible to breakage due to language or library changes.
  • However, good code should never access globals - the values set on window/self/global - except for those defined by the EcmaScript standard.
  • Such code, using import, is only susceptible to breakage if the EcmaScript standard or a library removes a property or completely redefines it.
  • In either case, code without import would be just as susceptible to future breakage