Gawk Reference Card distributed with gawk 3.0.98

[erik]

G'day,

   The card is splendid and helpful, but the Arrays stuff on page 11 may 
   mislead, I think. i.e.

>>>
   If the array has multiple subscripts, use (i,j) in array.

    Use the in construct in a for loop to iterate over all the elements of an
    array
<<<

   Iterating over a pseudo-multidimensional array is successful the old way:

#!/bin/sh

gawk '
BEGIN {  A[1,1,1] = "A"
         A[1,1,4] = "B"
         A[1,3,1] = "C"
         A[2,1,1] = "D"

         for (i in A)
         {  split(i,B,SUBSEP)    # A la Addison-Wesley book, by A&W&K.
            printf("%s:%s:%s:-> %s\n",B[1],B[2],B[3],A[i])
         }

#        for ((i,j,k) in A)
#        {  printf("%s:%s:%s:-> %s\n",i,j,k,A[i,j,k])
#        }
}'

   giving (with gawk 3.0.98):

1:3:1:-> C
1:1:1:-> A
1:1:4:-> B
2:1:1:-> D

   but once uncommented, in naive reliance on page 11, we have:

gawk: cmd. line:12:                     for ((i,j,k) in A)
gawk: cmd. line:12:                                      ^ parse error

   If I am missing something, then we might still benefit from the
   addition of a clue to that section. Neh?

   Otherwise, the second quoted Reference card sentence, above, could profitably
   be replaced with something along the lines of:

>>>
   To iterate over an array:           for (n in x)
   If "multi-dimensional", may need:   {  split(n,A,SUBSEP)
   Now A[1] = i, A[2] = j, A[3] = k, if x is the array above.
<<<

   Waddaya reckon?

Regards,
Erik

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