Suggestion Backlog Slog, 10/5/2015

[RyanCavanaugh]

Planned for discussion today

• Suggestion: Add the nameof compile-time operator to convert property and function names into strings #1579 nameof operator
• Contextual typing of object literal getters not working for return expressions #1611 contextually type getter return statements in object literal methods
• Support proposed ES Rest/Spread properties #2103 rest/spread object properties (Stage 2 ES7 proposal), https://github.com/sebmarkbage/ecmascript-rest-spread
• Index signature parameter type should allow for enums #2491 allow enums as index signature keys
• Cannot do anything before super() #3311 relax rules around super call
• Should treat const and enum (at least const enum) value the same as literals for indexers. #3411 indexing by a const enum should be the same as a literal (in tuples)
• T.constructor should be of type T #3841 constructor property of classes should point to the static side of the class
• Proposal: Expose collection element's type #3749 allow var x: typeof expr[0] (useful for arrays and tuples)
• Transpile separate scope in each for loop iteration with let and ES5 #3915 downlevel emit captured lets in for loops
• Publish typescript on Bower #4035 publish TypeScript on Bower
• Consider only showing builders in object literal completions its contextual type has an index signature #4089 when an object literal is contextually typed by an unindexed type, don't set allowNewIdentifiers = true in the LS
• Parameter signatures of functions in object literals are not always inferred correctly. #4241 contextually type function parameters even when other parameters have type annotations
• Syntax suggestion: Ignore last void parameters #4260 allow trailing void parameters to be omitted in function calls
• Expanded type guard suggestions #4868 more type guards (typeof x === 'function' or 'object')
• Infer Type Guard Return Values #5101 when a function's return expression is a recognized type guard (e.g. x instanceof y), automatically infer the function itself to be a type guard

[RyanCavanaugh]

• Suggestion: Add the nameof compile-time operator to convert property and function names into strings #1579 nameof operator
  • Some overlap with memberof proposal we have floating around somewhere
  • What if Rename / Find References solved this instead?
  • Punt and see if related approved suggestions address this sufficiently
• Contextual typing of object literal getters not working for return expressions #1611 contextually type getter return statements in object literal methods
  • Won't Fix due to complexity in how we fix parameters during overload resolution and lack of feedback
• Support proposed ES Rest/Spread properties #2103 rest/spread object properties (Stage 2 ES7 proposal), https://github.com/sebmarkbage/ecmascript-rest-spread
  • May or may not happen in ES7
  • Wait until it gets closer to landed before we commit to any semantics
• Index signature parameter type should allow for enums #2491 allow enums as index signature keys
  • Meh.
• Cannot do anything before super() #3311 relax rules around super call
  • 👍 disallow access to this in lexically-before super calls
• Should treat const and enum (at least const enum) value the same as literals for indexers. #3411 indexing by a const enum should be the same as a literal (in tuples)
  • 👍 for const enums only
• T.constructor should be of type T #3841 constructor property of classes should point to the static side of the class
  • This isn't actually statically true
  • ... but neither are some other things we say
  • Accepting PRs
• Proposal: Expose collection element's type #3749 allow var x: typeof expr[0] (useful for arrays and tuples)
  • 👍 allow numeric and string literals only in the brackets
• Transpile separate scope in each for loop iteration with let and ES5 #3915 downlevel emit captured lets in for loops
  • We error in this case instead of screwing you over
  • Vlad has a proposal / PR
  • Disallow labelled break in this case, but allow standard break
  • Make sure to hoist vars in the body
  • 👍
• Publish typescript on Bower #4035 publish TypeScript on Bower
  • 👍 accepting PRs
• Consider only showing builders in object literal completions its contextual type has an index signature #4089 when an object literal is contextually typed by an unindexed type, don't set allowNewIdentifiers = true in the LS
  • 👎 we screw this up in the wrong direction too often
• Parameter signatures of functions in object literals are not always inferred correctly. #4241 contextually type function parameters even when other parameters have type annotations
  • Breaking change, but in a good way. "Fixing" change under noImplicitAny
  • 👍 Accepting PRs
• Syntax suggestion: Ignore last void parameters #4260 allow trailing void parameters to be omitted in function calls
  • 👍 Accepting PRs
• Expanded type guard suggestions #4868 more type guards (typeof x === 'function' or 'object')
  • 👍 Accepting PRs. Do we have any other pending type guard work?
• Infer Type Guard Return Values #5101 when a function's return expression is a recognized type guard (e.g. x instanceof y), automatically infer the function itself to be a type guard
  • Too complex, low-yield. Write isFoo separately (and generically?) to get this to work