ref: ab4d1165045bde1fc5b291368e63b0bc0dd7a75d
parent: 03857943018a82e1101cecbb026b5e11f4061dc5
author: Ori Bernstein <ori@eigenstate.org>
date: Sat Feb 6 20:27:46 EST 2016
Add iter utils.
--- a/lib/std/bld.sub
+++ b/lib/std/bld.sub
@@ -33,6 +33,7 @@
intparse.myr
introspect.myr
ipparse.myr
+ iterutil.myr
mk.myr
mkpath.myr
mktemp.myr
--- /dev/null
+++ b/lib/std/iterutil.myr
@@ -1,0 +1,61 @@
+use "types"
+
+pkg std =
+ type zipiter(@a, @b) = struct
+ s1 : @a[:]
+ s2 : @b[:]
+ ;;
+
+ type enumiter(@a) = struct
+ s : @a[:]
+ idx : size
+ ;;
+
+ impl iterable zipiter(@a, @b) -> (@a, @b)
+ impl iterable enumiter(@a) -> (size, @a)
+
+ generic byzip : (a : @a[:], b : @b[:] -> zipiter(@a, @b))
+ generic byenum : (a : @a[:] -> enumiter(@a))
+;;
+
+generic byzip = {a, b+ -> [.s1 = a, .s2 = b]
+}
+
+impl iterable zipiter(@a, @b) -> (@a, @b) =
+ __iternext__ = {itp, valp+ if itp.s1.len > 0 && itp.s2.len > 0
+ valp# = (itp.s1[0], itp.s2[0])
+ itp.s1 = itp.s1[1:]
+ itp.s2 = itp.s2[1:]
+ -> true
+ else
+ -> false
+ ;;
+ }
+
+ __iterfin__ = {itp, valp+ }
+;;
+
+
+generic byenum = {a+ -> [.s = a, .idx = 0]
+}
+
+impl iterable enumiter(@a) -> (size, @b) =
+ __iternext__ = {itp, valp+ if itp.s.len > itp.idx
+ valp# = (itp.idx, itp.s[itp.idx])
+ itp.idx++
+ -> true
+ else
+ -> false
+ ;;
+ }
+
+ __iterfin__ = {itp, valp+ }
+;;
+
+
--- /dev/null
+++ b/lib/std/test/iterutil.myr
@@ -1,0 +1,19 @@
+use std
+
+const main = {+ var n
+
+ n = 0
+ for (x, i) in std.byenum([0,2,4,6,8][:])
+ std.assert(x == n, "invalid enum idx")
+ std.assert(i == n*2, "invalid enum val")
+ n++
+ ;;
+
+ n = 0
+ for (a, b) in std.byzip([0,2,4,6,8][:], [2,4][:])
+ std.assert(a == n*2, "invalid val from a")
+ std.assert(b == n*2 + 2, "invalid val from b")
+ n++
+ ;;
+}