Note: this document is a collection of all proposals from the Nim v2 ideas thread. As such, it is/was not by any means reflective of intentions for 2.0: though I've updated this with accepted and implemented proposals.
Features
- kobi, exelotl, didlybom, solomonthewise, pdkoekfr, snej, apropos: Adopt Options module and make types
not nilby default (discussion) - Zoom, apropos: Overhaul stdlib to work with view types and/or options/results for error handling
- ElegantBeef, elcritch, apropos: Increase code reuse with concepts, openarrays, and distincts (details)
- Zoom: Make slices return openarrays
- kobi: Pick an interface library and stick with it so error messages are clear
- exelotl: Destructors for files (RFC#316)
- Sixte: Introduce visibility rules for types
- [planned] jblin, apropos: Replace object variants with Rust/Haxe style algebraic data types (details, discussion: RFC#525, RFC#527)
Removals
- Yardanico, exelotl, didlybom, JPLRouge, ingo: Remove backwards-compatible switches / deprecated features
- sekao, didlybom, r3c, junelac, SunnyCorleone: Get rid of style insensitivity (discussion: RFC#456)
- Clonk: Remove style insensitivity in keywords and module names
- didlybom, cmc: Remove less used experimental features
- [somewhat implemented]
didlybom: Remove every memory option except orc, arc, none, go (related: RFC#177) - didlybom: Remove overlapping language features
- ingo, stisa: Shrink stdlib (by creating "batteries" libraries?)
- gcao: Move JavaScript (exists), WASM (doesn't exist) support to libraries (LLVM support is currently a library)
- apropos, Derick: Remove
%*JSON operator - cmc: Change pragma syntax to be easier on the eyes and the fingertips
Syntax
- exelotl, didlybom, r3c, TiffanyR, apropos, elcritch: Comprehensive stdlib cleanup
- markus_gritsch, TiffanyR:
newSeq()andnewString()==>initSeq()andinitString() - xigoi, namisboss: Change object initialization syntax to use
=instead of:for consistency - xigoi: Allow using newlines instead of commas
- xigoi: Make built-in types capitalized
- [planned, iirc]
xigoi: Requirestd/for importing standard library modules - volodymyr: Consistent stdlib module naming (ex: plural vs. singular)
- elcritch: Default enum scoped names
- TiffanyR: Replace all usages of
/with.(except for division) - apropos, Derick, Sixte: Replace
*withpubas the public marker - planetis: Do over
forloop syntax (details)
Features
- Zoom, cumulonimbus: Get continuation-passing style (CPS) into the core (RFC#295)
- Object construction:
- Sixte: Introduction of existential types
- kobi: Continue with flow sensitive typing
- kobi, didlybom: Unify methods and procs
- kobi: Popularize exception effects catching (raises pragma)
- [implemented]
solomonthewise: Strict funcs by default - volodymyr: Language support for a HashTable
- cumulonimbus: Language features designed for parallelism
- cumulonimbus: Do the least bad form of error handling
- mildred: Transform the stdlib into a collection of approved Nimble packages (discussion: RFC#371)
Syntax
- xigoi: Make
objectsyntactic sugar fordistinct tuple(RFC#321?) - xigoi: Make duck typing for generics opt-in
- volodymyr: Language support for
with - volodymyr: Language support for function piping/chaining
- volodymyr: Support multi-position assignments without tuples
- volodymyr: Extendible eager comprehensions (covered by sugar.collect?)
- volodymyr: Container subsetting (R)
- cumulonimbus: Explicit tail calls
- hyl: Improve module/function disambiguity with UFCS
Improvements
- Yardanico, gcao, exelotl, r3c, jasonfi, Zoom, SolitudeSF, carterza: Internal compiler refactoring
- Relevant: ringabout's work and nimskull
- sky_khan: Rid compiler of globals and make it an object for being compiled as a dynamic library
- r3c, stisa: Separate AST from codegen stage in the compiler
- r3c: Improve stdlib performance
- apropos:
rangeimprovements (details, discussion: RFC#172, RFC#541)
Features
- SFR0815, guzba, giaco, kobi, Clonk, zevv, apropos: Mutually recursive module imports and types (RFC#6)
- Zoom, exelotl, didlybom, r3c, kobi, krakengore, cmc: Complete/polish implementations of Nim's nice features:
- federico3, giaco, junelac, solomonthewise: Include more batteries
- [implemented]
guzba, slangmgh: Lock in--threads:onand--mm:arc/--mm:orc(planned (RFC#437): threads pr, mm pr) - giaco, deech, apropos: Official support for auto-generation of C wrappers (adopt Futhark) (manual wrappers still desired)
- bather, didlybom, volodymyr: Add
sugartosystem(particularly->and=>) - bather, didlybom, cblake: Add
sugartostd/preludeand makepreludework as a regular import - didlybom, volodymyr, jblin: Official, robust support for pattern matching (discussion: RFC#537)
- didlybom, solomonthewise, apropos: Official support for nimpy
- JPLRouge, solomonthewise: Official GUI library
- nimoid: Nested types (issue)
- elcritch: Provide a
SomeStringtype - elcritch: Module actions / triggers on import
- gcao: Robust WASM, LLVM support
- archnim: Data structure to hold mixed types (that isn't a JSON node)
- SunnyCorleone: Improve Tables (see Python Dicts)
- SunnyCorleone: GUI debugger
- [implemented]
treeform: Official support for overloadable enum names - pdkoekfr: Concurrency as a language primitive (details)
- cmc: Expand type inference (try again for return types, sugar for variant types)
- avandy: Move contract support into the stdlib
Syntax
- markus_gritsch: Allow tabs for indentation (disallow mixing)
- detla: "Weak imports" (don't warn unused by default, just ignore)
- cblake:
import foo {.used.} - nocturn9x: Allow redeclaring the same field in different object variant cases
- xigoi: Make object variants declare the type for the discriminator (like sum types elsewhere)
- didlybom, solomonthewise: Shorthand for defining sum types
Improvements
- Zoom, slangmgh, didlybom, volodymyr, cumulonimbus, treeform, federico3, cmc: Robust concurrency/multithreading (Go)
- coffeepot, sls1005: stdlib performance improvements with modern Nim features (ex. less Copy, more sink)
- giaco, krakengore, didlybom, jasonfi, r3c, thadeudepaula, solomonthewise, murdohekku, pdkoekfr, apropos: Improve tooling (status: RFC#300)
- detla: Better tooling for tracking where procs came from
- thadeudepaula: Tooling should support user style (ex. snake_case vs. camelCase)
- thadeudepaula: Better tooling around overloads
- foderking, krakengore, thadeudepaula: Compiler error improvement
- Zoom, giaco, kobi, treeform: Fix bugs!
- sekao, treeform, jasonfi, mildred: Don't break things for the sake of breaking things!
- r3c, solomonthewise, murdohekku, apropos: Better documentation, best practices, use cases
- giaco, murdohekku, apropos: Solve the anti-virus false positives
- 12398890: More powerful memory profiler
- kobi: Bug fixes around methods
- krakengore: Broadly improve includes and imports
- krakengore, solomonthewise: Detailed compiler documentation/specs (see also: Internal compiler refactoring)
- [implemented]
thadeudepaula: Explicit roadmap and goals (RFC#437, RFC#543) - treeform:
.and.=handling bugfixes - treeform: Import/iterator strangeness
- treeform: Windows bugfixes
- cmc: Easier metaprogramming
Even broken up into breaking / potentially breaking / not breaking changes, the list of suggestions was hard to parse, so I broke it up some more. The new categories are "features" (suggestions calling for a new feature or extending existing features), "removals" (suggestions calling for removals), "syntax" (suggesions relating to language syntax), and "improvements" (agreeable changes: ex. improve documentation).
You can view the uncategorized version in the revision history here. If I miscategorized anything, just let me know.