E07090: 'default' modifier is only valid for constructors, not regular methods

Category: E07xxx Full resolution · Reported in phase: SYMBOL_DEFINITION · Classification: DEFAULT_ONLY_FOR_CONSTRUCTORS · All error codes

What went wrong

You've used 'default' modifier on a regular METHOD, but 'default' is only valid for constructors and operators.

Worked examples

Compilable examples demonstrating this error and the correct fix:

ek9 -q 109 (How do I use composition instead of inheritance in EK9?)

How to fix it

Remove 'default' from method
Provide explicit implementation
Use 'default' only on constructors or operators

Common causes

Confusion about 'default' keyword purpose
Trying to provide auto-generated method
Misunderstanding which constructs support default

Examples

Every example is compiled by the EK9 compiler: the first fails exactly as captioned, the others fix it.

Fails with E07090: 'default' modifier is only valid for constructors, not regular methods

#!ek9
defines module error.e07090.bad

  defines record
    R1
      prop1 <- String()

      //Valid: default constructor
      default R1()

      //Invalid: default on regular method in record
      default getValue()
        <- rtn as String: String(prop1)

  defines trait
    T1
      //Invalid: default on regular method in trait (with body)
      anotherMethod() as pure abstract
        -> text as String
        <- rtn as String?

      default someMethod() as pure
        -> text as String
        <- rtn as String: String(text)

      //Valid: abstract method without default

  defines class
    C1
      //Valid: default constructor
      default C1()

      //Invalid: default on regular method with body
      default normalMethod()
        -> text as String
        <- rtn as String: String(text)

      //Valid: regular method without default
      validMethod()
        -> text as String
        <- rtn as String: String(text)

  defines component
    Comp1
      //Valid: default constructor
      default Comp1()

      //Invalid: default on regular method in component
      default processData()
        -> data as String
        <- rtn as String: String(data)

Fixed: Remove 'default' from the method

#!ek9
defines module error.e07090.good

  defines class
    Greeter
      //'default' is fine on a constructor
      default Greeter()

      //A method is written, never 'default'
      greet()
        -> greeting as String
        <- rtn as String: String(greeting)

Questions and answers

These Q&A entries show E07090 and its fix: