[draft PR D20190811T003919]

[timotheecour]

draft for nim-lang#11992

fixed issues

• symbols of no argument templates can't be passed to macros nim-lang/Nim#11870
• Cannot pass inline iterator to inline iterator nim-lang/Nim#4516
• type inference with lambdas doesn't work (requires explicit types) nim-lang/Nim#7435
• supersedes [TODO] Nim now supports true lambdas; eg allows map(a~>a*localVar) (wo limitations of sugar.nim =>) nim-lang/Nim#8679 (see rationale)
• RFC: Lambda expression (with inferred placeholders) nim-lang/Nim#8675
• RFC: Lambda expression (with inferred placeholders) nim-lang/Nim#8675
• [TODO] fix issue #8303 map overly restrictive nim-lang/Nim#8325
• simplifies things like sorted/sort and lots of algorithms; can directly pass a lambda; makes it more efficient (no callback / function frame overhead, ensures inlining)
• supersedes [superseded] alias: myecho=echo to alias any symbol nim-lang/Nim#11822

related

• [parser] a => counter+=1 parsed as (a => counter) += 1, violating the spec, and causing issues with => nim-lang/Nim#8759

• discusion wrt functor / cmp / free function: Change how void parameters work nim-lang/RFCs#508

• [RFC] Better iterators syntax nim-lang/RFCs#1