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Re^2: Can't locate print error

by Athanasius (Archbishop)
on Dec 03, 2015 at 10:27 UTC ( [id://1149285]=note: print w/replies, xml ) Need Help??


in reply to Re: Can't locate print error
in thread Can't locate print error

Yes, but with use strict; in force, why does perl -c give no errors for the two PRINT barewords?

Athanasius <°(((><contra mundum Iustus alius egestas vitae, eros Piratica,

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Re^3: Can't locate print error
by choroba (Cardinal) on Dec 03, 2015 at 10:30 UTC
    Indirect object notation. Method names aren't checked for existence before runtime.
    ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord }map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

      Hello choroba,

      Yes, ok, thanks, I guess that makes sense: the parser can’t know in advance whether a yet-to-be-imported object has a particular method or not. But it’s still a bit strange:

      21:54 >perl -c -Mstrict -wE "PRINT OUT 42;" -e syntax OK 21:55 >perl -c -Mstrict -wE "PRINT 42;" Number found where operator expected at -e line 1, near "PRINT 42" (Do you need to predeclare PRINT?) syntax error at -e line 1, near "PRINT 42" -e had compilation errors. 21:55 >perl -c -Mstrict -wE "PRINT;" Bareword "PRINT" not allowed while "strict subs" in use at -e line 1. -e had compilation errors. 21:55 >perl -c -Mstrict -wE "PRINT(42);" -e syntax OK 21:55 >

      Why does PRINT 42; produce a compile error, but PRINT(42) not? There’s no possibility of an indirect object in the latter case, is there?

      Athanasius <°(((><contra mundum Iustus alius egestas vitae, eros Piratica,

        PRINT 42 is a compile time error, because strict subs is in scope and PRINT hasn't been declared.

        PRINT(42) is syntactically correct, but will die once you remove the -c, as no PRINT sub was declared. Again, the sub can come from something like

        eval ' sub PRINT { print 1 + shift }';

        so you can't say during compile time whether PRINT will exist once you'll need it.

        ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord }map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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