Suggestion Backlog Slog, 11/02/2015

[RyanCavanaugh]

On the docket today

• Allow type parameter constraints to reference other type parameters #2304 Allow type parameter constraints to reference other type parameters
• Boolean literal types and return type propagation for generators #2983 Boolean literal types and return type propagation for generators
• Why are TS get/set definedProperties in a class transpiled as enumerable/writable? #3610 Why are TS get/set definedProperties in a class transpiled as enumerable/writable?
• Report errors if union subtype reduction results in fewer types than were explicitly written #3862 Report errors if union subtype reduction results in fewer types than were explicitly written
• tsc: Display source line and mark position where error occurred #4024 tsc: Display source line and mark position where error occurred
• Contextually type class property initializers by extends/implements types #3667 Contextually type class property initializers by extends/implements types
• Consider contextually typing class member functions by their base class/interface members #1373 Consider contextually typing class member functions by their base class/interface members
• For var in object: Var is implicitly any without error #4518 For var in object: Var is implicitly any without error
• Inference fails for return-type of intersection between class and generic type #5456 Inference fails for return-type of intersection between class and generic type
• Create and expose an expression transpiler #4169 Create and expose an expression transpiler
• To/from assignability is too strict of a check for comparison and other operations #5300 To/from assignability is too strict of a check for comparison and other operations
• Contextual typing does not flow backward through function return types to the function arguments #5256 Contextual typing does not flow backward through function return types to the function arguments
• Design preview: Stateless Functional Components in JSX #5478 Stateless Functional Components in JSX

[RyanCavanaugh]

Notes

• Allow type parameter constraints to reference other type parameters #2304 Allow type parameter constraints to reference other type parameters
  • It was in the old compiler and we were having problems. We don't remember why we disabled this.
  • Maybe try turning it off the check? It might just work
  • New circularities might arise
  • Anders will think about it
• Default generic type variables #2175 Default generic type variables
  • Can we just default to the constraint?
  • Does the 'missing' constraint correspond to a default of {} ?
  • This would bring up the possibility of named type parameter lists
  • Proposal: Allow to default to the explicit type parameters. What do people think?
• Why are TS get/set definedProperties in a class transpiled as enumerable/writable? #3610 Why are TS get/set definedProperties in a class transpiled as enumerable/writable?
  • Approved
  • Breaking change for ES6 compat's sake
• Report errors if union subtype reduction results in fewer types than were explicitly written #3862 Report errors if union subtype reduction results in fewer types than were explicitly written
  • Moot
• Suggestion: The object primitive type #1809 The object primitive type
  • Seems useful
  • 👍; we can implement
• tsc: Display source line and mark position where error occurred #4024 tsc: Display source line and mark position where error occurred
  • Colorize instead of squiggles
  • Only show the first line when there is a multi-line error span
  • 👍
• Contextually type class property initializers by extends/implements types #3667 Contextually type class property initializers by extends/implements types
  • Experiment with this. Looks promising
• Consider contextually typing class member functions by their base class/interface members #1373 Consider contextually typing class member functions by their base class/interface members
  • Union all multiple signatures from multiple implemented interfaces
  • 👍
• Use different relation when checking overload vs implementation signature compatibility #943 Use different relation when checking overload vs implementation signature compatibility
  • Discussion with no outcome