Logical Expressions

Idio allows you to use external commands in logical and conditional expressions. An external command is “true” if it exited with a status of 0 (zero). Any other form of exit is a logical “false”.

This would normally fly in the face of the aggressive behaviour of Idio regarding external command exits but the effective behaviour from using command logic is far more useful and all “exit on error” code is implicitly suppressed in logical and conditional expressions.

command-logic.idio

;; fall through the logical combination of five external commands
(or (false)
    (not (true))
    (and (true)
      (not false)
      (false))
    (puts "All failed\n"))

;; a more familiar test using an pipeline of external commands
if (env | grep SECRETSQUIRREL) {
  puts "Okay, Secret!\n"
} {
  puts "Nothing to do.\n"
}

$ idio command-logic
All failed
Nothing to do.

Last built at 2024-11-21T07:11:45Z+0000 from 77077af (dev) for Idio 0.3