A.19.1 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 |