how to do for loop based on a limit in Ant

In Ant-contrib, we can do something like:

<for list="a,b,c,d" param="instence">

But if I don't have a list, I only have a limit, e.g. limit=4.

Is there a way to do for loop based on limit, like:

<for limit="4" param="index">

Solution

The Ant addon Flaka provides some solutions for your problem.

1) Use a while loop

the test attribute evaluates some EL expression,
which maybe a simple counter, f.e.

<project name="demo" xmlns:fl="antlib:it.haefelinger.flaka">

 <!-- some counter -->
 <fl:let>
  countdown = 3
 </fl:let>

 <fl:while test=" countdown >= 0 ">
  <fl:echo>
   #{countdown > 0 ? countdown : 'bang!' }..
  </fl:echo>
  <fl:let>
   countdown = countdown - 1
  </fl:let>
 </fl:while>

</project>

output:

  [fl:echo] 3..
  [fl:echo] 2..
  [fl:echo] 1..
  [fl:echo] bang!..

or some other expression, f.e. checking for existence of a file, means looping until some file exists :

 <fl:while test=" !'/home/rosebud/stop'.tofile.isfile ">
  <fl:echo>
   still working..
  </fl:echo>
 </fl:while>

2) Use a for loop with break or continue :

<project name="demo" xmlns:fl="antlib:it.haefelinger.flaka">

 <fl:for var="i" in=" list(1,2,3,4,5,6) ">
    <fl:echo>i = #{i}</fl:echo>
    <fl:break test=" i == 3 " />
 </fl:for>

  <fl:for var="i" in=" list(1,2,3,4,5,6) ">
    <fl:continue test=" i > 3 " />
    <fl:echo>i = #{i}</fl:echo>
 </fl:for>

</project>

which gives the same result :

  [fl:echo] i = 1
  [fl:echo] i = 2
  [fl:echo] i = 3

See more details in the Flaka manual