E01080: 'self' does not exist in EK9 - use 'this' keyword

Category: E01xxx Parsing and excluded constructs · Reported in phase: SYMBOL_DEFINITION · Classification: SELF_NOT_SUPPORTED · All error codes

What went wrong

The 'self' keyword does not exist in EK9.

Worked examples

Compilable examples demonstrating this error and the correct fix:

ek9 -q 793 (Why does EK9 reject None and self as identifiers?)

Rationale

EK9 uses 'this' instead of 'self':

Consistent with Java, C++, JavaScript conventions
EK9 targets developers from multiple language backgrounds
'this' is implicit in most contexts

How to fix it

Replace 'self' with 'this', or omit it entirely when unambiguous.

See also

E01077: 'def' not supported (EK9 uses function name directly)
E01078: 'elif' not supported (use 'else if')
E01079: 'None' not supported (use tri-state semantics)
E01080: 'self' not supported (use 'this')
E01081: list comprehensions not supported (use stream pipelines)

https://ek9.io/classes.html https://ek9.io/forAI.json#$.excludedFeatures.features[?(@.keyword=="self")]

Examples

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

Fails with E01080: 'self' does not exist in EK9 - use 'this' keyword

#!ek9
defines module error.e01080.bad

  defines class

    Person
      name as String: "Steve"

      greeting()
        <- rtn as String: "I am " + self.name

      default operator ?

Fixed: Use 'this', or just the property name when that is unambiguous

#!ek9
defines module error.e01080.good

  defines class

    Person
      name as String: "Steve"

      greeting()
        <- rtn as String: "I am " + this.name

      shortGreeting()
        <- rtn as String: "I am " + name

      default operator ?

Questions and answers

These Q&A entries show E01080 and its fix:

Q793: Why does EK9 reject None and self as identifiers?