Algorithmic Composition: A Guide to Composing Music with Nyquist

Appendix. SAL Commands and Functions

232 Appendix SAL Commands and Functions The following lists summarize commands and functions used in this book. For details on command syntax and a complete list of functions, see the Nyquist Reference Manual. In some cases optional or keyword parameters are not mentioned here to simplify the presentation. Commands begin-end – execute a sequence of commands. define variable – declare and initialize a variable. define function – declare and define a function. display – print variable names and values. if-then-else – conditionally evaluate commands. load – evaluate the commands in a file. loop-end – iteratively evaluate commands. play – play a sound. print – print the values of expressions to the output window. return – return a value to the function calling expression. set – associate or bind a variable to the value of an expression. with – declare local variables. Functions List Functions length(list) – length of a list or string. first(list), car(list) – first element of a list. second(list) – second element of a list. third(list) – third element of a list. fourth(list) – fourth element of a list. rest(list), cdr(list) – remainder of list after the first element. nth(n, list) – get list element at position n. nthcdr(n, list) – get remainder of list starting at position n. reverse(list) – reverse the order of list. cons(head, list) – construct a list of head followed by list. list(e1, e2, …) – construct a list from elements. append(list1, list2, …) – construct a new list by concatenating lists. member(expr, list) – search for expr in list. Appendix ⋅ SAL Commands and Functions 233 assoc(expr, alist) – look up expr in an association list. intersection(list1, list2) – set intersection, treating lists as sets. union(list1, list2) – set union, treating lists as sets. set-difference(list1, list2) – set difference, treating lists as sets. subsetp(list1, list2) – is list1 a subset of list2? mapcar(function, list1) – apply function to each element of list. Math Functions (See Table 3.3.1 for a list of operators) round(x) – round x to an integer. truncate(x) – round x down to an integer. abs(x) – absolute value of x. min(x, y, …) – minimum value of inputs. max(x, y, …) – maximum value of inputs. interpolate(x, x1, y1, x2, y2) – linear interpolation. random(i) – random integer from 0 to i–1. rrandom() – random float (real) from 0 to 1. real-random(x, y) – random float (real) from x to y. Pattern Functions (See Table 5.3.1 for a list of pattern generators.) next(expr) – get the next item from a pattern object. Predicate (Test) Functions atom(x) – is x an atom? endp(x) – is x the end of a list (nil)? evenp(x) – is x even? floatp(x) – is x a float (real, floating point, flonum)? integerp(x) – is x an integer? listp(x) – is x a list? minusp(x) – is x negative? null(x) – is x nil? numberp(x) – is x a number? oddp(x) – is x odd? plusp(x) – is x positive? symbolp(x) – is x a symbol? zerop(x) – is x zero? Quoting Functions quote(s) – returns expression (or symbol) s without evaluation. keyword(s) – convert (unevaluated) symbol s to a keyword. Score Functions timed-seq(score) – render score returning a sound. Appendix • SAL Commands and Functions 234 Appendix ⋅ SAL Commands and Functions score-adjacent-events(score, function) – apply function to events. score-append(score1, score2, …) – append scores. score-apply(score1, function) – apply function to each event. score-filter-length(score, cutoff) – remove notes playing past cutoff. score-get-begin(score) – get the begin time. score-get-end(score) – get the end time. score-index-of(score, function) – find first note satisfying function. score-last-index-of(score, function) – last note satisfying function. score-merge(score1, score2, …) – create score combining all notes. score-play(score) – render a score to sound and play it. score-randomize-start(score, amt) – perturb note start times. score-read-smf(filename) – read standard MIDI file into a score. score-repeat(score, n) – repeat a score n times. score-scale(score, keyword, x) – scale each keyword’s value by x. score-select(score, function) – select notes that satisfy function. score-set-begin(score, time) – set score beginning to time. score-set-end(score, time) – set score ending to time. score-sort(score) – sort events in score into time order. score-sustain(score, x) – scale each note duration by x. score-transpose(score, keyword, x) – add x to each keyword value. score-voice(score, list) – replace...