What features from other languages does EK9 deliberately exclude?

← Getting Started · Ref: Q880

EK9 DELIBERATELY EXCLUDES these features. They are not missing — they were removed based on decades of production bug evidence:

NO break — use 'head N' in streams or guard expressions instead
NO continue — use 'filter by' in streams instead
NO return — declare the return variable with '<-', compiler ensures all paths set it
NO null — EK9 uses tri-state (absent/unset/set) with the '?' operator
NO type casts — use promotion '#^' or explicit conversion
NO switch fallthrough — each case is independent, use comma-separated values
NO public keyword — methods are public by default, 'public' is redundant and rejected
NO new keyword — constructors are called directly: 'MyClass()' not 'new MyClass()'
NO semicolons — indentation defines scope
NO braces — indentation defines scope

The grammar literally does not contain these keywords. You cannot write 'break' — the parser will reject it.

See Q144 for no break/continue/return. See Q145 for replacements. See Q29 for no null.

Example

defines module qa.getting.started.exclusions

  defines constant

    TEEN_AGE <- 13
    ADULT_AGE <- 18

  defines function

    classifyAge() as pure
      -> years as Integer
      <- rtn as String: "unknown"

      //No 'return' — set rtn on each path
      if years < TEEN_AGE
        rtn: "child"
      else if years < ADULT_AGE
        rtn: "teenager"
      else
        rtn: "adult"

  defines program

    ExclusionsDemo()
      stdout <- Stdout()

      //No 'new' keyword — just call the constructor
      names <- List() of String
      names += "Steve"
      names += "Limb"
      stdout.println(`Names: ${length names}`)

      //No 'null' — use ? to check
      unsetName <- String()
      if not unsetName?
        stdout.println("Name is unset, not null")

      stdout.println(classifyAge(25))

Coming from another language?

All languages: these features exist everywhere else. EK9: removed from grammar entirely. Not deprecated, not warned — gone.

Keywords: fallthrough, missing, exclude, design, break, return, null, cast, continue