You can use a {.experimental: "ForLoopMacros".} to rewrite the for loop.
See for example the impelmentation of Python enumerate
import macros
{.experimental: "forLoopMacros".}
macro enumerate*(x: ForLoopStmt): untyped =
expectKind x, nnkForStmt
# we strip off the first for loop variable and use
# it as an integer counter:
result = newStmtList()
result.add newVarStmt(x[0], newLit(0))
var body = x[^1]
if body.kind != nnkStmtList:
body = newTree(nnkStmtList, body)
body.add newCall(bindSym"inc", x[0])
var newFor = newTree(nnkForStmt)
for i in 1..x.len-3:
newFor.add x[i]
# transform enumerate(X) to 'X'
newFor.add x[^2][1]
newFor.add body
result.add newFor
Run
and usage
for a, b in enumerate(items([1, 2, 3])):
echo a, " ", b
Run
I'll have a look at refactoring that for enums (unless someone gives it a go
first) though I fear it might only work at top level.
Also I'm pretty sure you meant narimiran instead of me ;).
