How does EK9 detect reference conflicts and unresolved references?

← Code Quality · Ref: Q741

EK9 validates all module references at compile time and detects two categories of problems.

REFERENCES CONFLICT (E03020)

The same symbol cannot be referenced twice in a references block. Each external symbol should appear exactly once. Duplicating a reference serves no purpose and may indicate a copy-paste error.

REFERENCE DOES NOT RESOLVE (E03030)

A reference must point to an existing module and symbol. If the module path or symbol name is misspelled, or the module does not exist, the compiler rejects the reference. This catches typos and stale references early.

CORRECT PATTERNS

Ensure each reference appears once and points to a valid module::Symbol. Use fully qualified inline access as an alternative to the references block.

See Q726 for module reference syntax. See Q142 for cross-module constants.

Example

defines module qa.codequality.referenceconflicts

  defines function

    formatItem() as pure
      -> text as String
      <- rtn as String: `[${text}]`

  defines program

    ReferenceConflictsDemo()
      stdout <- Stdout()

      //Direct function call within same module
      result <- formatItem("hello")
      stdout.println(result)
      stdout.println(formatItem("world"))

Common mistakes

E50060 — String has no getValue() method. formatItem() already returns a String. See ek9 -h E50060 for details.

Incorrect:

result <- formatItem("hello").getValue()

Correct:

result <- formatItem("hello")

E50060 — String has no toString() method in EK9. The function already returns a String. See ek9 -h E50060 for details.

Incorrect:

stdout.println(formatItem("world").toString())

Correct:

stdout.println(formatItem("world"))

Coming from another language?

Java: duplicate imports produce warnings. Python: duplicate imports silently overwrite. Rust: duplicate use statements produce errors. Go: unused imports are errors. EK9: duplicate references and unresolved references are both compile-time errors.

Keywords: E03030, resolve, quality, conflict, import, module, duplicate, E03020, missing, reference