Execute HQ9+: Difference between revisions

=={{header|REXX}}==

<lang rexx>

/*the HQ9+ language.*/ parse arg pgm .

do instructions=1 for length(pgm)

_=substr(pgm,instructions,1)

select

when _=='H' then say "hello, world"

when _=='Q' then do j=1 for sourceline()

say sourceline(j)

end

when _==9 then call 99

when _=='+' then if symbol(accumulator)=='VAR' then accumulator=accumulator+1

otherwise say 'invalid HQ9+ instruction:' _

end /*select*/

end /*instructions*/

exit

99: do j=99 by -1 to 1

say j 'bottle's(j) "of beer the wall,"

say j 'bottle's(j) "of beer."

say 'Take one down, pass it around,'

n=j-1

if n==0 then n='no' /*cheating to use 0. */

say n 'bottle's(j-1) "of beer the wall."

say

end

say 'No more bottles of beer on the wall,' /*finally, last verse.*/

say 'no more bottles of beer.'

say 'Go to the store and buy some more,'

say '99 bottles of beer on the wall.'

return

s: if arg(1)=1 then return ''; return 's' /*a simple pluralizer.*/

</lang>

Output when using the input of:

<br><br>

H+Q

<pre style="height:40ex;overflow:scroll">

hello, world

/*the HQ9+ language.*/ parse arg pgm .

do instructions=1 for length(pgm)

_=substr(pgm,instructions,1)

select

when _=='H' then say "hello, world"

when _=='Q' then do j=1 for sourceline()

say sourceline(j)

end

when _==9 then call 99

when _=='+' then if symbol(accumulator)=='VAR' then accumulator=accumulator+1

otherwise say 'invalid HQ9+ instruction:' _

end /*select*/

end /*instructions*/

exit

99: do j=99 by -1 to 1

say j 'bottle's(j) "of beer the wall,"

say j 'bottle's(j) "of beer."

say 'Take one down, pass it around,'

n=j-1

if n==0 then n='no' /*cheating to use 0. */

say n 'bottle's(j-1) "of beer the wall."

say

end

say 'No more bottles of beer on the wall,' /*finally, last verse.*/

say 'no more bottles of beer.'

say 'Go to the store and buy some more,'

say '99 bottles of beer on the wall.'

return

s: if arg(1)=1 then return ''; return 's' /*a simple pluralizer.*/

</pre>