enable closures tests for JS & implement finished for JS

changelog.md

@@ -19,6 +19,8 @@
 
 - JS backend now supports lambda lifting for closures. Use `--legacy:jsNoLambdaLifting` to emulate old behavior.
 
+- JS backend now supports closure iterators.
+
 ## Standard library additions and changes
 
 [//]: # "Changes:"

compiler/jsgen.nim

@@ -611,6 +611,17 @@ template unaryExpr(p: PProc, n: PNode, r: var TCompRes, magic, frmt: string) =
  r.res = frmt % [a, tmp]
  r.kind = resExpr
 
+proc genBreakState(p: PProc, n: PNode, r: var TCompRes) =
+ var a: TCompRes = default(TCompRes)
+ # mangle `:state` properly somehow
+ if n.kind == nkClosure:
+ gen(p, n[1], a)
+ r.res = "(($1).HEX3Astate < 0)" % [rdLoc(a)]
+ else:
+ gen(p, n, a)
+ r.res = "((($1.ClE_0).HEX3Astate) < 0)" % [rdLoc(a)]
+ r.kind = resExpr
+
 proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
  var
  x, y: TCompRes = default(TCompRes)
@@ -3043,16 +3054,7 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
  of nkGotoState, nkState:
  globalError(p.config, n.info, "not implemented")
  of nkBreakState:
- var a: TCompRes = default(TCompRes)
- if n[0].kind == nkClosure:
- gen(p, n[0][1], a)
- let sym = n[0][1].typ[0].n[0].sym
- r.res = "(($1).$2 < 0)" % [rdLoc(a), mangleName(p.module, sym)]
- else:
- gen(p, n[0], a)
- let sym = n[0].typ[0].n[0].sym
- r.res = "((($1.ClE_0).$2) < 0)" % [rdLoc(a), mangleName(p.module, sym)]
- r.kind = resExpr
+ genBreakState(p, n[0], r)
  of nkPragmaBlock: gen(p, n.lastSon, r)
  of nkComesFrom:
  discard "XXX to implement for better stack traces"

lib/system.nim

@@ -2348,8 +2348,14 @@ when notJSnotNims:
  `result` = `x`.ClE_0;
  """.}
 
- proc finished*[T: iterator {.closure.}](x: T): bool {.noSideEffect, inline, magic: "Finished".} =
- ## It can be used to determine if a first class iterator has finished.
+proc finished*[T: iterator {.closure.}](x: T): bool {.noSideEffect, inline, magic: "Finished".} =
+ ## It can be used to determine if a first class iterator has finished.
+ when defined(js):
+ # TODO: mangle `:state`
+ {.emit: """
+ `result` = (`x`.ClE_0).HEX3Astate < 0;
+ """.}
+ else:
  {.emit: """
  `result` = ((NI*) `x`.ClE_0)[1] < 0;
  """.}

tests/closure/t8550.nim

@@ -1,4 +1,5 @@
 discard """
+ targets: "c js"
  output: "@[\"42\"]"
 """
 

tests/closure/tnested.nim

@@ -1,4 +1,5 @@
 discard """
+targets: "c js"
 output: '''
 foo88
 23 24foo 88
@@ -183,14 +184,32 @@ block tclosure2:
 
 import typetraits
 
-proc myDiscard[T](a: T) = discard
+block:
+ proc myDiscard[T](a: T) = discard
 
-proc foo() =
- let a = 5
- let f = (proc() =
- myDiscard (proc() = echo a)
- )
- echo name(typeof(f))
+ proc foo() =
+  let a = 5
+  let f = (proc() =
+  myDiscard (proc() = echo a)
+  )
+  echo name(typeof(f))
 
-foo()
+ foo()
 
+
+block:
+ iterator foo: int {.closure.} =
+ yield 1
+ yield 2
+ yield 3
+
+ proc pork =
+ let call = foo
+ for i in call():
+ discard i
+
+ let call2 = foo
+ while not finished(call2):
+ discard call2()
+
+ pork()

tests/iter/t1550.nim

@@ -1,3 +1,7 @@
+discard """
+ targets: "c js"
+"""
+
 type
  A[T] = iterator(x: T): T {.gcsafe, closure.}
 

tests/iter/t21306.nim

@@ -1,3 +1,7 @@
+discard """
+ targets: "c js"
+"""
+
 # bug #21306
 type
  FutureState {.pure.} = enum

tests/iter/t2771.nim

@@ -1,3 +1,7 @@
+discard """
+ targets: "c js"
+"""
+
 template t1(i: int): int=
  i+1
 template t2(i: int): int=

tests/iter/tanoniter1.nim

@@ -1,4 +1,5 @@
 discard """
+ targets: "c js"
  output: '''1
 2
 3

tests/iter/tclosureiters.nim

@@ -1,4 +1,5 @@
 discard """
+ targets: "c js"
  output: '''0
 1
 2
@@ -152,15 +153,18 @@ iterator filesIt(path: string): auto {.closure.} =
  yield prefix / f
 
 # bug #13815
-var love = iterator: int {.closure.} =
- yield cast[type(
- block:
- var a = 0
- yield a
- a)](0)
-
-for i in love():
- echo i
+when not defined(js):
+ var love = iterator: int {.closure.} =
+ yield cast[type(
+ block:
+ var a = 0
+ yield a
+ a)](0)
+
+ for i in love():
+ echo i
+else:
+ echo 0
 
 # bug #18474
 iterator pairs(): (int, int) {.closure.} =

tests/iter/titer11.nim

@@ -1,4 +1,5 @@
 discard """
+targets: "c js"
 output: '''
 [
 1

tests/iter/titer12.nim

@@ -1,4 +1,5 @@
 discard """
+targets: "c js"
 output: '''
 Selecting 2
 1.0

tests/iter/titer_issues.nim

@@ -1,4 +1,5 @@
 discard """
+ target: "c js"
  output: '''
 0
 1