ISCOVE%UTOROCI.BITNET@cornellc.cit.cornell.edu (03/09/89)
The Enhancer 1.3 manual p 2-12 gives the following example
for use of "c/EVAL" to count loops in a script:
.key loop/a
.bra {
.ket }
echo >env:loop {loop}
lab start
echo "Loop #" noline
type env:loop
eval <env:loop >NIL: to=t:qwe{$$} value2=1 op=-?
type >env:loop t:qwe{$$}
IF val $loop GT 0
skip start back
endif
echo "done"
In practice, the example fails when eval is called. ram:env/loop was
correctly set up beforehand, and ENV: assigned as RAM:ENV.
eval <env:loop - 1 to t:qwe{$$} also fails. The following also fails from
the Shell along with numerous permutations:
> setenv loop 5
> type env:loop ; correctly returns 5
> eval <env:loop + 2 ; returns 0 instead of 7
Can anyone help with the proper syntax here?
Commodore?
Norman Iscove ISCOVE@UTOROCI.bitnetadam@cbmvax.UUCP (Adam Levin CATS) (03/10/89)
In article <10437@louie.udel.EDU> ISCOVE%UTOROCI.BITNET@cornellc.cit.cornell.edu writes: >The Enhancer 1.3 manual p 2-12 gives the following example >for use of "c/EVAL" to count loops in a script: (All of script deleted except for offending line) > eval <env:loop >NIL: to=t:qwe{$$} value2=1 op=-? > >In practice, the example fails when eval is called. ram:env/loop was >correctly set up beforehand, and ENV: assigned as RAM:ENV. There needs to be a space between the minus sign (-) and the question mark (?). It is hard to judge it in the line as printed, but the space is there. >eval <env:loop - 1 to t:qwe{$$} also fails. The following also fails from >the Shell along with numerous permutations: > >> setenv loop 5 >> type env:loop ; correctly returns 5 >> eval <env:loop + 2 ; returns 0 instead of 7 > >Can anyone help with the proper syntax here? >Commodore? Use eval <env:loop >NIL: to=* op=+ 2 ? The question mark, usually used to get the template of the command, is being used here to make the command get its arguments from standard input. Usually standard input will be the console the command is typed in on, but because of the <env:loop redirection, standard input is taken from env:loop. However, env:loop only has one argument in it, so the rest are taken from the command line. The >NIL: redirection is used to avoid displaying the template which the question mark invoked. However, this means that the result of the command also gets sent to NIL:. The "to=*" argument causes the results of the command to be sent to "*" the console device the command was typed in on. See how easy computers make things? > >Norman Iscove ISCOVE@UTOROCI.bitnet Adam -- Adam Keith Levin -- CATS Commodore-Amiga Technical Support 1200 Wilson Drive / West Chester, PA 19380 (215) 431-9180 BIX: aklevin UUCP: ...{amiga|rutgers|uunet}!cbmvax!adam