R5RS primary predicates
Primary predicates can be applied to any expression. They can
be used on their own as predicates for LilyPond functions.
The predicates here are part of the Scheme standard R5RS.
| Type predicate | Description |
|---|
boolean? | boolean |
char? | character |
complex? | complex number |
eof-object? | end-of-file object |
input-port? | input port |
integer? | integer |
list? | list (use cheap-list? for faster processing) |
null? | null |
number? | number |
output-port? | output port |
pair? | pair |
port? | port |
procedure? | procedure |
rational? | rational number |
real? | real number |
string? | string |
symbol? | symbol |
vector? | vector |