SPUG: "Boolean" return values

[Colin Meyer]

On Mon, Oct 13, 2008 at 03:03:26PM -0700, Michael R. Wolf wrote:
> Does anyone know the motivation for the return values from the boolean 
> operators?

We have boolean context, but not boolean operators. Maybe "!". Most of
the logical operators have return values based on their input.

> 
> true  returns (numeric) 1
> false returns (string)  ''
> 
> Why not just 0 and 1?  Why the mix of numeric and string?

They return a multi-valued scalar:

    > perl -MDevel::Peek -le'Dump( ! "" ); Dump( ! 0 );'
    SV = PVNV(0x605060) at 0x2af2764040d0
      REFCNT = 2147483647
      FLAGS = (IOK,NOK,POK,READONLY,pIOK,pNOK,pPOK)
      IV = 1
      NV = 1
      PV = 0x606030 "1"\0
      CUR = 1
      LEN = 8
    SV = PVNV(0x605060) at 0x2af2764040d0
      REFCNT = 2147483647
      FLAGS = (IOK,NOK,POK,READONLY,pIOK,pNOK,pPOK)
      IV = 1
      NV = 1
      PV = 0x606030 "1"\0
      CUR = 1
      LEN = 8

In a string context, that will be "1"; Integer or real: 1; Boolean: true;

The return values for false are similarly multivalued.

-Colin.