A Kotlin compiler plugin providing some useful-for-scripting checks.

• Integer overflow and numeric precision checks
  • All integer operations have checks when working with both Int and Long, for built-in operations as well as the Iterable extension functions
  • Converting from Int to Float or from Long to either floating-point type is checked for precision, where any number too large to be guaranteed to be exactly represented will throw an exception
  • Performing remainder operations will warn if the result would be negative (warns up to once, can be disabled on any platform other than wasm¹)
  • Checks can be disabled with @SkipOverflowChecks
• Collection destructuring checks
  • When destructuring from a collection (e.g. val (a, b, c) = myList), all elements of the list must be accounted for, otherwise an exception is thrown
  • Anonymous parameter names do function (for a three-element list, calling val (a, _, _) = myList will silence the checks without requiring unused names for the other parameters, while still enforcing the list to have a size of 3)
  • Checks can be disabled with @SkipDestructuringChecks
• @Memoize annotation on functions
  • When the annotation is applied to the function, the plugin will add a map of inputs previously used to the corresponding outputs. This assumes the function does not have side effects or its callers are not dependent on the side effects.
  • Special handling done for zero through three arguments to avoid list instantiation (instead opting for object instantiation)
  • When annotating a method with zero arguments, the annotation essentially becomes a fancy lazy

¹ On JVM, setting chekt.warnOnNegativeRemainder to "false" will disable the warning. On native platforms, setting KT_REM_WARNINGS environment variable to false will disable the warning. On JS, setting any value to a cookie called chekt.warnOnNegativeRemainder will disable the warning.

Apply to a Gradle project:

plugins {
    // kotlin("...") version "..."
    id("com.sschr15.chekt") version "(Gradle plugin version)"
}

This will automatically apply the compiler plugin.

• Enum-exhaustive functions and maps
• whatever else I can think of