Issues

• REPL print(10) produces confusing overload-resolution errors, while file mode reports a clear type error

  effekt-lang/effekt#1477 · Filter by author amistozy opened on Oct 5, 2026

• Syntax sugar idea: Effect patterns

  featurequality-of-liferequires-design
  effekt-lang/effekt#1476 · Filter by author marzipankaiser opened on Oct 2, 2026
  1

• Rename 'compare$Type' to '$Type::compare'

  area:stdlibquality-of-liferefactoring
  effekt-lang/effekt#1436 · Filter by author jiribenes opened on Aug 21, 2026

• Module paths of stdlib tests wrong

  effekt-lang/effekt#1433 · Filter by author martin-ilgner opened on Aug 17, 2026

• Add a 'Word' (64 bits) primitive type

  featurerequires-design
  effekt-lang/effekt#1431 · Filter by author jiribenes opened on Aug 14, 2026

• Values of type 'Any' can be converted to everything

  area:corearea:patternmatchingarea:typerbug
  effekt-lang/effekt#1426 · Filter by author jiribenes opened on Aug 14, 2026

• Optimize nullary constructors to singletons on JavaScript

  area:compilerarea:js
  effekt-lang/effekt#1425 · Filter by author jiribenes opened on Aug 11, 2026

• Compiler crash because of an unexpected abort in DummyUnifier

  effekt-lang/effekt#1399 · Filter by author 4y8 opened on May 28, 2026
  8

• Name resolution for method calls is inconsistent

  requires-design
  effekt-lang/effekt#1397 · Filter by author marzipankaiser opened on May 4, 2026
  1

• Miscompilation of closure capture on JS

  area:cpsarea:jsbug
  effekt-lang/effekt#1385 · Filter by author jiribenes opened on Apr 21, 2026
  2

• Use extern type definitions in LLVM

  area:llvmfeaturerequires-design
  effekt-lang/effekt#1378 · Filter by author marzipankaiser opened on Apr 13, 2026

• Investigate deletion of module declaration

  feature
  effekt-lang/effekt#1375 · Filter by author phischu opened on Apr 13, 2026
  5

• Generate generic representation

  area:compilerfeaturequality-of-life
  effekt-lang/effekt#1374 · Filter by author phischu opened on Apr 13, 2026
  2

  

• Mistranslation of recursively forwarded effects in JS backend

  area:jsbug
  effekt-lang/effekt#1358 · Filter by author marzipankaiser opened on Apr 8, 2026
  4

• Implement inlining / optimizations on continuation IR

  area:chezarea:cpsarea:jsoptimizer-wishlist
  effekt-lang/effekt#1343 · Filter by author b-studios opened on Mar 25, 2026

• Consider relooping recursive LetDefs on JS CPS

  area:jsexperiment
  effekt-lang/effekt#1341 · Filter by author jiribenes opened on Mar 24, 2026

• Add benchmark configs for 'nofib' and 'folklore to fact'

  effekt-lang/effekt#1335 · Filter by author jiribenes opened on Mar 21, 2026
  6

• Investigate using macros in Chez CPS runtime

  area:chez
  effekt-lang/effekt#1333 · Filter by author jiribenes opened on Mar 21, 2026

• Overloaded function is preferred over an overloaded operation

  bug
  effekt-lang/effekt#1324 · Filter by author jiribenes opened on Mar 18, 2026
  2

• java.lang.ClassCastException when handling an effect alias of an interface

  bugerrormessagefirst-hackathon-issue
  effekt-lang/effekt#1318 · Filter by author marvinborner opened on Mar 6, 2026
  6

  

• Type annotations for patterns

  area:parser/lexerarea:patternmatchingarea:typer
  effekt-lang/effekt#1308 · Filter by author jiribenes opened on Mar 3, 2026
  2

  

• Always specialize non-recursive functions with regard to their function arguments

  experimentfeature
  effekt-lang/effekt#1290 · Filter by author phischu opened on Jan 20, 2026
  3

• Compiler panic "?C should be a concrete capture set in this phase."

  bug
  effekt-lang/effekt#1289 · Filter by author marvinborner opened on Jan 19, 2026
  3

  

• Multiple return values in Core

  area:corefeature
  effekt-lang/effekt#1285 · Filter by author phischu opened on Jan 13, 2026
  1

• llvm: segmentation fault caused by time-travelling region variable

  area:llvmbug
  effekt-lang/effekt#1281 · Filter by author kyay10 opened on Jan 5, 2026
  1