Scheme Scripting Cookbook:
Jon Fernquest's Open Programming Directory

Goals:

1. Use higher order functions and functional style programming as tools for creating compact, simple, readable, provable, and reusable scripts.
2. Quick partial parsing and extraction of information using parsing combinators (sort of like regular expressions for non-regular languages)
3. Fold functions with state for tree recursion applied to directory trees and reporting on tree-like databases.
4. Immitate functional style declarative GUI programming.
5. Parsing and locating noun phrases relevant for a search engine query using functional style Categorial Grammars.
6. Combine the power of functional and object oriented programming with Scheme's Tiny CLOS.
7. Include introductory snippets for language teachers who want ot use Scheme as a scripting language to find words and grammar examples in texts, i.e. Corpus Linguistics.

(These programs all run under PLT Scheme (aka Dr Scheme, MzScheme). Ultimately, I want to get them to run under Guile and Chicken with a small footprint.

Directory Tree Cumulative Disk Usage

• dirlist.scm prints out indented directory tree with cumulative totals of megabytes (rollups) for every directory.
• filefilter.scm filters out all lines (directories) over a threshhold amount of disk space from an indented-directory-tree file. [output: Over 10MB: dirlist_10.txt , Over 100 MB: dirlist_100.txt are example outputs]
• readintolist1.scm copy file to new file reversing lines

Higher-Order Functions

• treetravcomb1.scm N-ary tree traversal combinators. (In a call to foldt (tree fold) different traversals are generated by different combinations of list fold (foldl,foldr) and the list constructor (cons,cons-reverse) as arguments.)
• summation1.scm Higher order summation functions. (based on Cousineau and Mauny, The Functional Approach to Programming" in CAML, p42-43)
• treebinua.scm binary tree upwards accumulation ; (based on Jeremy Gibbons, Generic Downwards Accumulations)
• unfold1.scm unfold examples from Oxford unfold paper, foldt (fold tree) and foldf (fold forest), preorder, level-order, and breadth first tree and forest traversal
• zipstrange1.scm assorted strange zip functions

Regular Expressions (using Sitaram's pregexp):

• findall1.scm find all regex matches in a string (like Python's 'findall')
• regexptest2.scm extracting HTML tags from strings
• pregexp7.scm extract all lines in a file that match a regex and write them to another file
• pregexp9.scm search for all instances of a last name in the works of Balzac.

Text Processing:

• filline1.scm wrapping text into fixed length lines
• split1.scm split a delimited string into substrings

Awk Examples:

• awk2.scm adding line numbers to the left margin of a file (with proper line number formatting (using string-pad))
• awk1.scm using Dr Scheme's awk macro (modelled on Scsh) to do the same match as pregexp7.scm above in only a few lines of code

Timing a Program:

• vectormap1.scm: vector mapping functions, timing a scalar multiplying a thousand long vector by 2 (10,000 repetitions) finding average time in milliseconds, (note: should look at the frequency distribution seems to alternate between taking no time and significant amount of time)

Objects and Records

• object1.scm, objpat1.scm, objpat2.scm, objpat3.scm: Object-Oriented MzScheme programming using examples from Falleisan and Mattheisan's book (dealing with OO Java and design patterns in a functional style)
• object1.scm simplest possible objects using mzscheme/drscheme objects

MORE TO COME