Machaut Messe Performance Performance Performance Isorhythm Isorhythm

Review

Remember All Lisp expressions must have matched parentheses; that is, every open paren must appropriately have a closed paren. All Lisp expressions must have matched parentheses; that is, every open paren must appropriately have a closed paren. Document all of your work by placing comments after a “;” or enclosing in “”, or placing between #| this is documentation |# Document all of your work by placing comments after a “;” or enclosing in “”, or placing between #| this is documentation |# Name variables and everything you do such that later on you can tell what they mean and does. Name variables and everything you do such that later on you can tell what they mean and does.

Remember Readability everything Readability everything

One flew over the parentheses nest! One flew over the parentheses nest!

Hummmmmmm (+ (first *my-numbers*) (+ (first *my-numbers*) (third *my-numbers*) (third *my-numbers*) (first *my-numbers*)) (first *my-numbers*)) Note how much easier the above is to read than: (+ (first *my-numbers*)(third *my-numbers*)(first *my-numbers*)) (+ (first *my-numbers*)(third *my-numbers*)(first *my-numbers*)) 4

More exercises (nth 5 ‘( )) (nth 5 ‘( )) 6 Remember to check whether the primitive you’re using is zero or one based as in Remember to check whether the primitive you’re using is zero or one based as in (nthcdr 5 ‘( )) (nthcdr 5 ‘( )) 6 whew whew

More? (position 1 '( )) (position 1 '( )) 1 (position 2 '( )) 0 And so on.

From ( ) get: From ( ) get: 1) 0 1) 0 2) 64 2) 64 3) ) ) ( ) 4) ( ) 5) ( ) 5) ( ) 6) ( ) 6) ( ) 7) (0 1) 7) (0 1) 8) ((0)) 8) ((0)) 9) ( ) 9) ( ) 10) (60 0) 10) (60 0)

From (((a) b) c) get: From (((a) b) c) get: 1) a 1) a 2) c 2) c 3) b 3) b 4) (a b) 4) (a b) 5) (a (b c))) 5) (a (b c)))

From (a b c d e) get: From (a b c d e) get: 1) (d e) 1) (d e) 2) 5 2) 5 3) (a (b (c (d (e))))) 3) (a (b (c (d (e))))) 4) (e d c b a) 4) (e d c b a) 5) (a b c d) 5) (a b c d)

From a get: From a get: 1) (a) 1) (a) 2) (a. a) 2) (a. a) 3) (a (a)) 3) (a (a)) 4) ((a) a) 4) ((a) a) 5) (a ()) 5) (a ())

From a and (b c) get: From a and (b c) get: 1) (a b c) 1) (a b c) 2) ((a) b c) 2) ((a) b c) 3) (a (b c)) 3) (a (b c)) 4) (a c) 4) (a c) 5) (c b a) 5) (c b a)

From (a b) and (c d) get: From (a b) and (c d) get: 1) (a b c d) 1) (a b c d) 2) ((a b) c d) 2) ((a b) c d) 3) ((a b)(c d)) 3) ((a b)(c d)) 4) (b a d c) 4) (b a d c) 5) (a (b c) d) 5) (a (b c) d)

(append '((1)) '(2 3)) (append '((1)) '(2 3))

((1) 2 3) ((1) 2 3)

(append '((2)(3)) '(4 5)) (append '((2)(3)) '(4 5))

((2) (3) 4 5) ((2) (3) 4 5)

(first '(((a)) (b c d e))) (first '(((a)) (b c d e)))

((A)) ((A))

(rest '(((((f)))))) (rest '(((((f))))))

nil nil

(first '(rest (a b c))) (first '(rest (a b c)))

rest rest

(first (second '(((1 2))(2 3 4)((5 6 7))))) (first (second '(((1 2))(2 3 4)((5 6 7)))))

2

(second (first '(((1 2))(2 3 4)((5 6 7))))) (second (first '(((1 2))(2 3 4)((5 6 7)))))

nil nil

Cope-event ( ) ( ) On-time (1000 per second) On-time (1000 per second) Pitch number (24 108) Pitch number (24 108) Duration (1000 per second) Duration (1000 per second) Channel (1-16) Channel (1-16) Loudness (1- 127) Loudness (1- 127)

Therefore ( ) ( ) Translates to Translates to A loud quarter-note middle C on channel 1 A loud quarter-note middle C on channel 1 Channel assignments are separate and (except for channel 10 usually) can produce any general MIDI sound Channel assignments are separate and (except for channel 10 usually) can produce any general MIDI sound When saved to MIDI file and opened in a notation program produces the above. When saved to MIDI file and opened in a notation program produces the above.

Cope-events (( )( )( )( )( )( )( )( )) (( )( )( )( )( )( )( )( )) Produces a loud C-major scale in quarter notes. Produces a loud C-major scale in quarter notes.

Some more functions + (can have any number of args) + (can have any number of args) - (can have any number of args) - (can have any number of args) / (can have any number of args) / (can have any number of args) * (can have any number of args) * (can have any number of args) sort (be careful) sort (be careful) exp exp sqrt sqrt sin, cosin, tan (etc.) sin, cosin, tan (etc.)

Predicates Some Lisp functions serve as test functions as in Some Lisp functions serve as test functions as in (listp 1) (listp 1) which returns nil because its argument is not a list which returns nil because its argument is not a list (atomp ‘(1)) (atomp ‘(1)) which returns nil because its argument is not an atom which returns nil because its argument is not an atom The suffix “p” stands for predicate The suffix “p” stands for predicate

Conditionals Some functions in Common Lisp—called conditionals—test data for certain attributes. Some functions in Common Lisp—called conditionals—test data for certain attributes. For example, the function if tests its first argument and returns its second argument if it proves true, or its third argument if it proves false. For example, the function if tests its first argument and returns its second argument if it proves true, or its third argument if it proves false.

Example ? (if (numberp 1) t nil) ? (if (numberp 1) t nil) Returns Returns T because “1” is a number and thus the first choice (t) is the result because “1” is a number and thus the first choice (t) is the result Note that Lisp is case insensitive. Note that Lisp is case insensitive.

Named This combination is often termed an if- then-else clause. This combination is often termed an if- then-else clause.

Quiz ? (if (numberp (second ‘(a 2 b d f)) ‘yes ‘no) ? (if (numberp (second ‘(a 2 b d f)) ‘yes ‘no) returns returns > yes > yes

Quiz ? (cons 1 (rest ‘( ))) ? (cons 1 (rest ‘( ))) returns returns > ( ) > ( )Whew.

Now you think of some questions!

Let’s try for a few combinations (defvar *my-numbers* ‘(1 2 3)) (defvar *my-numbers* ‘(1 2 3)) (if (equal (first *my-numbers*) 2) (if (equal (first *my-numbers*) 2) (third *my-numbers*) (third *my-numbers*) (first *my-numbers*)) (first *my-numbers*)) What’s the answer?

Answer 1

Another (append (append (append *my-numbers* *my-numbers*) (append *my-numbers* *my-numbers*) (rest *my-numbers*)) (rest *my-numbers*))

Answer ( ) ( )

A little harder (if *my-numbers* (last *my-numbers*) (if *my-numbers* (last *my-numbers*) ()) ())

Answer (3) (3) N.B. The function “last” returns a list of the last number. Weird, but true. N.B. The function “last” returns a list of the last number. Weird, but true.

Try this: (if (equal *my-numbers* (1 2 3)) (if (equal *my-numbers* (1 2 3)) (reverse *my-numbers*)) (reverse *my-numbers*))

Answer Error! (forget the single quote on data!!!) Error! (forget the single quote on data!!!)

Whew! (third ‘((((a)) b)(c ((d) e) f)(((g)) h I)) (third ‘((((a)) b)(c ((d) e) f)(((g)) h I))

Answer (((g)) h I)) (((g)) h I))