Generates a utility of padding, margins, width and font sizes

box-model.less

/ ............................................................
// .for
 
.for(@i, @n) {.-each(@i)}
.for(@n)     when (isnumber(@n)) {.for(1, @n)}
.for(@i, @n) when not (@i = @n)  {
    .for((@i + (@n - @i) / abs(@n - @i)), @n);
}
 
// ............................................................
// .for-each
 
.for(@array)   when (default()) {.for-impl_(length(@array))}
.for-impl_(@i) when (@i > 1)    {.for-impl_((@i - 1))}
.for-impl_(@i) when (@i > 0)    {.-each(extract(@array, @i))}
 
 
// Margin all classes
.m {
  .for(0 1 5 10 15 20 25 30 35 40 50 55 60 65 70 75 80 85 90 95 100); .-each(@name) {
    &@{name} {
      margin: ~"@{name}px"
    }
    &t@{name} {
      margin-top: ~"@{name}px"
    }
    &b@{name} {
      margin-bottom: ~"@{name}px"
    }
    &l@{name} {
      margin-left: ~"@{name}px"
    }
    &r@{name} {
      margin-right: ~"@{name}px"
    }
  }
}
 
// Auto margins
.m {
  .for(auto); .-each(@name) {
    &@{name} {
      margin: ~"@{name}"
    }
    &t@{name} {
      margin-top: ~"@{name}"
    }
    &b@{name} {
      margin-bottom: ~"@{name}"
    }
    &l@{name} {
      margin-left: ~"@{name}"
    }
    &r@{name} {
      margin-right: ~"@{name}"
    }
    &lr@{name} {
      margin-left: ~"@{name}";
      margin-right: ~"@{name}";
    }
  }
}
 
 
 
// Padding All Classes
.p {
  .for(0 1 5 10 15 20 25 30 35 40 50 55 60 65 70 75 80 85 90 95 100); .-each(@name) {
    &@{name} {
      padding: ~"@{name}px"
    }
    &t@{name} {
      padding-top: ~"@{name}px"
    }
    &b@{name} {
      padding-bottom: ~"@{name}px"
    }
    &l@{name} {
      padding-left: ~"@{name}px"
    }
    &r@{name} {
      padding-right: ~"@{name}px"
    }
  }
}
 
// All widths
.w {
  .for(0 5 10 15 20 25 30 35 40 50 55 60 65 70 75 80 85 90 95 100); .-each(@name) {
    &per@{name} {
      width: ~"@{name}%"
    }
    &px@{name} {
      width: ~"@{name}px"
    }
  }
}
 
//Font sizes
 
.fs {
  .for(0 5 10 15 20 25 30 35 40 50 55 60 65 70 75 80 85 90 95 100); .-each(@name) {
    &@{name} {
      font-size: ~"@{name}px"
    }
  }
}