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Please follow the traditional start-of-class approach.
Approximate overview
Scholarly
Artistic/Cultural
Multicultural
Peer
Musical, theatric, sporting, academic, and similar events involving this section’s students are welcome.
Wellness
Misc
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There are so many procedures in the reading. How important is it that we learn all of them?
I don’t expect you to memorize them, but you should know that “there’s a procedure that does this”, even if you can’t recall the name.
I do expect you to be able to read their use.
Don’t forget that we have flashcards (and that you have notebooks and cheat sheets).
I couldn’t make it to class today. Can I take the quizzes on another day?
You can take the makeups next week. One of the consequences of mastery grading is that I will generally push you to the next week rather than allowing you to make them at another time. (That also means that I can send out answers/notes more promptly.)
I will not go over these explicitly. You may want to look at them with your partner.
Why is the space character positioned at 32?
Computer scientists like powers of 2. This serves as a nice breaking point between characters that do something a bit atypical from those that print.
Why do we have to put \# in front of a character in order for char->integer to work?
The
\#tell the computer to treat the character as a character, rather than, say, an identifier (variable).
Why does char-lower-case? turn characters into diffferent characters?
char-lower-case?checks whether or not a character is lowercase. It returns either true (#t) or false (#f). That will make more sense once you read Monday’s readings.
You mention there is a way to implement alphabetic to the letter
characters, but how? Is it the #/a #/n #/z example that became #t?
Yes, it’s that example.
Was #f being placed in the “more character predicates” section also
mean it was false?
Yes.
What do the special chars represent?
It depends on the character. The ones less than 32 often represent special information we’d use in transferring data from computer to computer or keys on old-fashioned keyboards (like “bell”).
The ones over 128 are “unamerican” characters (not part of the standard US alphabet).
Why would we need to use this code?
To build and understand functions that work with text.
I would like to request, if possible, a demonstration or more clear
example on how and why you would use these functions like char<
Next week.
Use (list->string (list ...)) to make a string from a list. For example,
(list->string (list #\S #\a #\m #\R)) makes my name.
Sorry about the false alarm. I have no idea why my computer/watch went off like that.
Note: (string #\a #\" #\b) gives "a\"b". The backslash in the middle of
the string indicates “do not treat the double-quote immediately following
me as an end-of-string mark”, so the \" represents a single character.
Don’t forget to print both first and last name on the back of the quiz.