Summary: We investigate records in Scheme through experiments with a record for chemical compounds.
a. Start DrScheme.
b. Make a copy of
c. Scan through that file to make sure that you understand all the procedures.
a. Try the compoound examples given in the reading on records to see if they behave as I said they would.
b. Try a few of your own variations.
c. Explain why the attempted fake is not listed as a compound. Hint:
Think about the order of the
Define a procedure,
filter-by-color, that takes two arguments --
compounds of records of type
a color symbol -- and returns a list of the names of compounds of that
color that are elements of
a. Can you set the melting point of a compound to an illegal temperature? If so, how? If not, why not? (Note that there are other ways to modify compounds than to use the record's provided procedures.)
b. Find a way to make a vector that
as a compound. You may not use
compound-copy to build your new vector. However,
you may use either procedure to create a
from which you copy values.
Write a set of definitions for a record type,
be used in a program that keeps track of the inventory of a clothing store.
Provide fields for catalog number, intended gender of wearer, size, color,
price, and quantity in stock. Only the last two fields should be mutable.
Adapt the binary search procedure so that it takes two arguments -- a
vec, of records of type
and a catalog number,
catno -- and returns the entire record
that contains that catalog number, if there is one in
#f if there is no such record.
Define a procedure that sorts a vector of records of type
shirt into ascending order by catalog number.
Write an expression that, through an appropriate call to
mergesort, sorts a list of shirts by catalog number.
Rewrite your answer to the first sorting problem by using your answer to the previous problem.
Monday, 27 November 2000 [Samuel A. Rebelsky]
http://www.math.grin.edu/~stone/courses/scheme/records.xhtml(Created April 29, 1997; Last modified April 21, 2000)
Monday, 30 April 2001 [Samuel A. Rebelsky]
Tuesday, 3 December 2002 [Samuel A. Rebelsky]
Tuesday, 29 April 2003 [Samuel A. Rebelsky]
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