Add $integer_sequence(<begin>, <end>[, <step>]) function

It returns the list of uint64 integers starting from <begin> (including)
to <end> (excluding) with the specified <step> or 1 if unspecified. For
example:

hdr = foo.hxx bar.hxx baz.hxx
src = foo.cxx bar.cxx baz.cxx

assert ($size($hdr) == $size($src)) "hdr and src expected to be parallel"

for i: $integer_sequence(0, $size($hdr))
{
  h = ($hdr[$i])
  s = ($src[$i])
  ...
}

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/function/builtin/testscript b/tests/function/builtin/testscript
index 02c73ee..bbfd4e5 100644
--- a/tests/function/builtin/testscript
+++ b/tests/function/builtin/testscript
@@ -77,6 +77,14 @@
   $* <'print $type($identity(abc))'            >''         : untyped
 }
 
+: integer-sequence
+:
+{
+  $* <'print $integer_sequence(1, 3)'    >'1 2'     : basics
+  $* <'print $integer_sequence(1, 0)'    >''        : empty
+  $* <'print $integer_sequence(0, 8, 2)' >'0 2 4 6' : step
+}
+
 : string
 :
 {