Archive for the ‘Perl’ Category

PBP: 078 Value Switches

Monday, January 26th, 2015

The idea behind this Best Practice is to explain how a table lookup can be used instead of an if/elsif/elsif/elsif/elsif/else block to make selections from a set of constants.  This is almost always a good choice! (more…)

PBP: 077 Multipart Selections

Thursday, January 22nd, 2015

The PBP say “Avoid cascading an if.”  At first glance, this sounds like a pretty harsh suggestion.  As it turns out, I rarely ever have any issue following this suggestion.  Well organized code seems not to need long if/elsif/elsif/elsif/elsif/else blocks. (more…)

PBP: 076 List Processing Side Effects

Monday, January 19th, 2015

Mr. Conway suggests the very firm, “Never modify $_ in a list function.”  I’m torn on this. (more…)

PBP: 075 Complex Mappings

Thursday, January 15th, 2015

The PBP suggests we factor complex map blocks into subroutines.  Please, please do this! (more…)

PBP: 074 List Transformation

Monday, January 12th, 2015

The last Best Practice suggested using map instead of a for loop to process lists.  There is an exception suggested by the Best Practices; if you’re transforming a list in place, use a for loop. (more…)

PBP: 073 List Selections

Thursday, January 8th, 2015

The Best Practice is to use grep and first instead of for to refine or search lists.  Again, there are good reasons, but I find it difficult, and am only improving with deliberate practice. (more…)

PBP: 072 List Generation

Monday, January 5th, 2015

The Best Practice is to use map when generating a new list from an old one.  The reasoning is good, but I struggle with it anyway.  I’m getting better with effort. (more…)

PBP: 071 Non-Lexical Loop Iterators

Thursday, January 1st, 2015

The statement made by this Best Practice is simple, “Always declare a for loop iterator with my.”  The reasoning behind it is complex, and surprised me.  I am sure I have screwed this up in the past, too.  It’s important as there’s a real gotcha here! (more…)

PBP: 070 Iterator Variables

Monday, December 29th, 2014

Mr. Conway suggests that you give explicit names for all for loops, and avoid the possibly confusing use of $_.  To this I say: Hallelujah! (more…)

PBP: 069 Necessary Subscripting

Thursday, December 25th, 2014

In those places you do actually need both the key and value, you will have to go ahead and do the lookup on the key to get the value.  The PBP reminds us to only do that once, instead of many times in the loop. (more…)