Perl6

1
Perl6

• Michael Bryson
• Mark Staton
• Alex Varghese

2
Overview

• Perl stands for practical extraction and report
  language
• Was written as a language to scan text files,
  extract information from those files, and print
  reports based on that information

3
History

• Perl1 was written around 1987.
• Perl1 was mainly derived from C and to a lesser
  extent sed, awk, and the UNIX shell.
• Perl1 was written for the file manipulation
  discussed earlier.

4
History (cont.)

• Over the years, there have been many improvements
  in the language.
• Perl now supports modularity and object-oriented
  programming.
• Perl6 is the latest version and is a ground-up
  rewrite of the original source codes from
  versions 1 through 4.

5
History (cont.)

• The evolution of Perl to the present day Perl6
  allows programmers to perform or use
• Quick prototyping
• System utilities
• System management tasks
• Database access
• Graphical programming
• Networking
• World Wide Web programming

6
Interpreter/Compiler

• Perl is an interpreted language. This allows
  one to write programs without an intermediate
  compilation step. Not having a compilation step
  allows a programmer to experiment and test/debug
  quickly. Perl has also become a great
  replacement for shell scripting.

7
Syntax

• represents any scalar value
• _at_ represents a list
• represents a hash or associative array
• You always need for any block in Perl. i.e.
  after an if statement
• There are two sets of comparison operators. One
  set is for strings and the other is for numbers.

8
Parallel Data in Perl6

• Junctions are a parallel scalar data-type, to be
  introduced in Perl 6
• Four types of junctions
• Disjunctions
• Conjunctions
• Abjunctions
• Injunctions

9
Disjunctions (any)

• anyvalue any(_at_list_of_values)
• print A number is too large if anyvalue gt 10
• can also be defined using binary operator ()
• anyvalue first second
• third
• anyvalue fourth

10
Conjunctions (all)

• allvalues all(_at_list_of_values)
• print Must have positive number(s) if
  allvalues lt 0
• can also be defined using binary operator ()
• allvalues first second
• third
• allvalues fourth

11
Abjunctions (one)

• onevalue one(_at_list_of_values)
• print There is exactly one zero if onevalue
  0

12
Injunctions (none)

• novalue none(_at_list_of_values)
• print All negative numbers if novalue gt 0

13
More Junctions

• Junctions can also be used implicitly
• print all numbers must be positive if abc
  lt 0
• Junctions are simply scalars
• if (my_equals(value, any(_at_other_values)) ...
• Can be used for type declarations
• my CarTruck x
• my CarRedObject y
• my none(Truck) z
• Allows for easy parallelization
• if( sqrt( any(_at_some_numbers) ) gt 5 ) ...

14
Comparisons

• Perls expression syntax corresponds closely to
  C.
• If you have experience with C or using UNIX, it
  is relatively easy to learn Perl.
• On the surface, Perl and TCL are very similar.
  However, it is not until one is writing more
  complex programs and code that the differences
  become apparent.