1. LING/C SC/PSYC 438/538 Lecture 3 Sandiway Fong

2. Administrivia Homework 2 graded

3. Today’s Topics Homework 2 review – reminder: submit plain text or PDF please (no.doc/.docx) Perl

4. Short Homework 2 Review Is tough sledding an idiom or compositional in meaning? Compositional: – Meaning(tough sledding) = Meaning(tough) Meaning(sledding) – Literal meaning: "kick the bucket" Idiom: – Meaning(tough sledding): explicitly learned and stored

5. Short Homework 2 Review The chickens are ready to eat In what way(s) is this sentence structurally ambiguous? gardenbetty.com X eat Y X = the chickens Berkeley Parser

6. Short Homework 2 Review The chickens are ready to eat In what way(s) is this sentence structurally ambiguous? wikipedia X eat Y Y = the chickens

7. Short Homework 2 Review John said he dislikes nearly everyone he meets In what way(s) is this sentence referentially ambiguous? 1.John said John dislikes nearly everyone John meets 2.John said Pete dislikes nearly everyone Pete meets 3.John said Pete dislikes nearly everyone John meets 4.…

8. Perl Day Learn Perl – Books… see next slide – Online resources http://learn.perl.org/ we begin with... http://perldoc.perl.org/perlintro.html philosophy: Natural Language Principles in Perl If a language is designed so that you can ``learn as you go'', then the expectation is that everyone is learning, and that's okay. http://www.wall.org/~larry/natural.html philosophy: Natural Language Principles in Perl If a language is designed so that you can ``learn as you go'', then the expectation is that everyone is learning, and that's okay. http://www.wall.org/~larry/natural.html

9. Perl Day UA has free access to O'Reilly's Safari library: http://proquest.safaribooksonline.com.ezproxy2.library.arizona.edu/searc h?q=perl

10. Perl arrays and hashes Scalars: – strings, numbers (integers, floating point numbers), references Arrays: – Store multiple scalars together – Idea: list of scalars – Access by index: 0,1,2,… Hash (aka Associative Array): – Like an array except access not through a numeric index – Use user-specified keys $variable @variable %variable different namespaces: $apple @apple %apple are different data structures and can co-exist simultaneously different namespaces: $apple @apple %apple are different data structures and can co-exist simultaneously most programming languages will offer you all of these basic data types

11. Perl Week

13. Notes on arrays and hashes – arrays are indexed from 0,1,2,3… – hashes are like arrays with user-defined indexing (aka associative array or hash table) – initialization (use round brackets and commas) @a = (“zero”, “one”, “two”, “three”, “four”); %h = (“zero”, 0, “one”, 1, “two”, 2, “three”, 3, “four”, 4); (key/value pairs) – access to individual elements (square brackets vs. curly braces) $a[1]“one” $h{zero}0

14. Perl Week Notes on arrays and hashes – output print @azeroonetwothreefour print “@a”zero one two three four print %hthree3one1zero0two2four4 (note: different order) print “%h”%h (literal, no interpolation) What happens here? – %pos = ("apple", "n", "speak", "v", "happy", "a", "walk", "n", "walk", "v"); – print $pos{"walk"}, "\n"; (hash keys are unique) controlled by variable $” default: a space controlled by variable $” default: a space

15. Perl Week Conditionals – if ( @a < 10 ) { print “Small array\n” } else {print “Big array\n” } – Note: @a here is a scalar = size of array – unless (@a > 10) { print “@a\n” } – Note: if size of array a is ≤ 10, it prints the contents of array a Looping %fruits = ("apple", "green", "orange", "orange", "lemon", "yellow"); foreach $fruit (keys %fruits) { print $fruit, " => ", $fruits{$fruit}, "\n” } gives output: lemon => yellow apple => green orange => orange Note: apparently keys %fruits = (“lemon” “apple” “orange”) is an array