jyapayne/Nim
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Merge pull request #2184 from oderwat/feat-caseofwhen

Browse source 
Allow empty sets in case/of branches.
This commit is contained in:
Andreas Rumpf 2015-02-24 19:35:52 +01:00
commit 819a2a03ac
2 changed files with 30 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

8
compiler/semtypes.nim
View file

@ -452,6 +452,7 @@ proc semCaseBranchSetElem(c: PContext, t, b: PNode,
proc semCaseBranch(c: PContext, t, branch: PNode, branchIndex: int, proc semCaseBranch(c: PContext, t, branch: PNode, branchIndex: int,
covered: var BiggestInt) = covered: var BiggestInt) =
for i in countup(0, sonsLen(branch) - 2): for i in countup(0, sonsLen(branch) - 2):
var b = branch.sons[i] var b = branch.sons[i]
if b.kind == nkRange: if b.kind == nkRange:
@ -461,8 +462,11 @@ proc semCaseBranch(c: PContext, t, branch: PNode, branchIndex: int,
else: else:
# constant sets and arrays are allowed: # constant sets and arrays are allowed:
var r = semConstExpr(c, b) var r = semConstExpr(c, b)
# for ``{}`` we want to trigger the type mismatch in ``fitNode``: if r.kind in {nkCurly, nkBracket} and len(r) == 0 and sonsLen(branch)==2:
if r.kind notin {nkCurly, nkBracket} or len(r) == 0: # discarding ``{}`` and ``[]`` branches silently
delSon(branch, 0)
return
elif r.kind notin {nkCurly, nkBracket} or len(r) == 0:
checkMinSonsLen(t, 1) checkMinSonsLen(t, 1)
branch.sons[i] = skipConv(fitNode(c, t.sons[0].typ, r)) branch.sons[i] = skipConv(fitNode(c, t.sons[0].typ, r))
inc(covered) inc(covered)

24
tests/casestmt/tcase_emptyset_when.nim Normal file
View file

@ -0,0 +1,24 @@
discard """
file: "tcaseofwhen.nim"
outputsub: "compiles for 1\ni am always two\ndefault for 3\nset is 4 not 5\narray is 6 not 7\ndefault for 8"
exitcode: "0"
"""
proc whenCase(a: int) =
case a
of (when compiles(whenCase(1)): 1 else: {}): echo "compiles for 1"
of {}: echo "me not fail"
of 2: echo "i am always two"
of []: echo "me neither"
of {4,5}: echo "set is 4 not 5"
of [6,7]: echo "array is 6 not 7"
of (when compiles(neverCompilesIBet()): 3 else: {}): echo "compiles for 3"
#of {},[]: echo "me neither"
else: echo "default for ", a
whenCase(1)
whenCase(2)
whenCase(3)
whenCase(4)
whenCase(6)
whenCase(8)