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Support iterators returning lent T (#11938)

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* lent iterators
* rebase tests
* update changelog
* fix comments, more tests
This commit is contained in:
cooldome 2019-08-31 18:23:54 +01:00 • committed by Andreas Rumpf
commit 2b565aad89
7 changed files with 116 additions and 27 deletions
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59
compiler/semstmts.nim
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@ -678,25 +678,30 @@ proc semForVars(c: PContext, n: PNode; flags: TExprFlags): PNode =
var length = sonsLen(n)
let iterBase = n.sons[length-2].typ
var iter = skipTypes(iterBase, {tyGenericInst, tyAlias, tySink})
var iterAfterVarLent = iter.skipTypes({tyLent, tyVar})
# length == 3 means that there is one for loop variable
# and thus no tuple unpacking:
if iter.kind != tyTuple or length == 3:
if iterAfterVarLent.kind != tyTuple or length == 3:
if length == 3:
if n.sons[0].kind == nkVarTuple:
var mutable = false
if iter.kind == tyVar:
iter = iter.skipTypes({tyVar})
mutable = true
if sonsLen(n[0])-1 != sonsLen(iter):
if sonsLen(n[0])-1 != sonsLen(iterAfterVarLent):
localError(c.config, n[0].info, errWrongNumberOfVariables)
for i in 0 ..< sonsLen(n[0])-1:
var v = symForVar(c, n[0][i])
if getCurrOwner(c).kind == skModule: incl(v.flags, sfGlobal)
if mutable:
v.typ = newTypeS(tyVar, c)
v.typ.sons.add iter[i]
else:
v.typ = iter.sons[i]
case iter.kind
of tyVar:
v.typ = newTypeS(tyVar, c)
v.typ.sons.add iterAfterVarLent[i]
if tfVarIsPtr in iter.flags:
v.typ.flags.incl tfVarIsPtr
of tyLent:
v.typ = newTypeS(tyLent, c)
v.typ.sons.add iterAfterVarLent[i]
if tfVarIsPtr in iter.flags:
v.typ.flags.incl tfVarIsPtr
else:
v.typ = iter.sons[i]
n.sons[0][i] = newSymNode(v)
if sfGenSym notin v.flags: addDecl(c, v)
elif v.owner == nil: v.owner = getCurrOwner(c)
@ -712,15 +717,22 @@ proc semForVars(c: PContext, n: PNode; flags: TExprFlags): PNode =
elif v.owner == nil: v.owner = getCurrOwner(c)
else:
localError(c.config, n.info, errWrongNumberOfVariables)
elif length-2 != sonsLen(iter):
elif length-2 != sonsLen(iterAfterVarLent):
localError(c.config, n.info, errWrongNumberOfVariables)
else:
for i in 0 .. length - 3:
if n.sons[i].kind == nkVarTuple:
var mutable = false
if iter[i].kind == tyVar:
iter[i] = iter[i].skipTypes({tyVar})
mutable = true
var isLent = false
iter[i] = case iter[i].kind
of tyVar:
mutable = true
iter[i].skipTypes({tyVar})
of tyLent:
isLent = true
iter[i].skipTypes({tyLent})
else: iter[i]
if sonsLen(n[i])-1 != sonsLen(iter[i]):
localError(c.config, n[i].info, errWrongNumberOfVariables)
for j in 0 ..< sonsLen(n[i])-1:
@ -729,6 +741,9 @@ proc semForVars(c: PContext, n: PNode; flags: TExprFlags): PNode =
if mutable:
v.typ = newTypeS(tyVar, c)
v.typ.sons.add iter[i][j]
elif isLent:
v.typ = newTypeS(tyLent, c)
v.typ.sons.add iter[i][j]
else:
v.typ = iter[i][j]
n.sons[i][j] = newSymNode(v)
@ -737,7 +752,19 @@ proc semForVars(c: PContext, n: PNode; flags: TExprFlags): PNode =
else:
var v = symForVar(c, n.sons[i])
if getCurrOwner(c).kind == skModule: incl(v.flags, sfGlobal)
v.typ = iter.sons[i]
case iter.kind
of tyVar:
v.typ = newTypeS(tyVar, c)
v.typ.sons.add iterAfterVarLent[i]
if tfVarIsPtr in iter.flags:
v.typ.flags.incl tfVarIsPtr
of tyLent:
v.typ = newTypeS(tyLent, c)
v.typ.sons.add iterAfterVarLent[i]
if tfVarIsPtr in iter.flags:
v.typ.flags.incl tfVarIsPtr
else:
v.typ = iter.sons[i]
n.sons[i] = newSymNode(v)
if sfGenSym notin v.flags:
if not isDiscardUnderscore(v): addDecl(c, v)