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srfi.210
- Procedures and syntax for multiple valuesThis module provides macros and procedures to blend multiple-value expressions naturally into the orinary single-value expressions.
[SRFI-210]{srfi.210}
A shorthand notation of (call-with-values (^[] producer) consumer)
.
[SRFI-210]{srfi.210}
A shorthand notation of
(with-values producer (case-lambda clause …))
.
[SRFI-210]{srfi.210}
Similar to apply
, but the multiple values yielded
from the last argument (producer) is turned into the tail of
the argument list; that is,
(apply operator operand … (values->list producer))
.
[SRFI-210]{srfi.210} Calls proc with the argument produced by the expression producer … and ’splicing’ their result(s) into a single argument list.
(call/mv list (values 1 2 3) (values 4 5 6)) ⇒ (1 2 3 4 5 6)
[SRFI-210]{srfi.210} Returns a list, a vector, or a box, consisting of element … and the value(s) produced by producer.
Single-argument list/mv
is the same as Gauche’s values->list
(see Multiple values).
(list/mv 1 2 (values 3 4 5)) ⇒ (1 2 3 4 5) (vector/mv 1 2 (values 3 4 5)) ⇒ #(1 2 3 4 5) (box/mv 1 2 (values 3 4 5)) ⇒ #<mv-box[5] 1 2 3 4 5>
[SRFI-210]{srfi.210}
Returns the same value as
(list-ref (list/mv element … producer) index)
.
With no element …, it is the same as Gauche’s values-ref
(see Multiple values) except the argument order.
[SRFI-210]{srfi.210} Evaluate producer, and returns the number of values it yielded.
[SRFI-210]{srfi.210} Evaluate producer, and passes its results to the first transducer as arguments. The values returned by the first transducer are passed to the next transducer as arguments, and so on. Returns the results of the last transducer. The call to the last transducer is tail-call.
If no transducers are given, it returns the results of producer.
[SRFI-210]{srfi.210} Turn the content of lis, vec or box into multiple values.
Note that box-values
is the same as unbox
, but provided here
for the naming consistency (see Boxes).
[SRFI-210]{srfi.210} Returns the index-th value of obj ….
[SRFI-210]{srfi.210}
Synonym of values
. Note that this is different from
Gauche’s built-in identity
, which takes exactly one argument
(see Combinators).
[SRFI-210]{srfi.210}
Each transducer must be a procedure.
Returns a procedure that applies the first transducer to its
arguments, then applies the next transducer to the result(s)
of the first one, and so on. Returns the result(s) returned from
the last transducer. If no tranducers are given,
returned procedure is the same as values
.
This can be written using Gauche’s built-in compose
as follows
(see Combinators):
(define (compose-left . procs) (apply compose (reverse procs)))
[SRFI-210]{srfi.210}
Each transducer must be a procedure.
Returns a procedure that applies the last transducer to its
arguments, then applies the previous transducer to the result(s)
of the last one, and so on. Returns the result(s) returned from
the first transducer. If no tranducers are given,
returned procedure is the same as values
.
This is the same as Gauche’s built-in compose
(see Combinators).
[SRFI-210]{srfi.210} Returns a procedure that takes any number of arguments, applys proc on each argument, and returns the results as multiple values. The behavior is undefined if proc doesn’t return a single value.
((map-values (cut + <> 1)) 1 2 3) ⇒ 2, 3, 4
[SRFI-210]{srfi.210}
These are bind operation in Monads. The first argument
is the source of data; they’re first expanded into values (for
bind/list
, each element of lis is taken; for bind/box
,
it is unboxed, and for bind
, obj is the singleton value).
Those values are passed as arguments to the first transducer,
and its result(s) are passed as argumenst to the second transducer
and so on. The value(s) returned by the last transducer becomes
the result(s) of those procedures. These can be written using
compose-left
and procedure application:
(bind/list lis proc …) ≡ (apply (compose-left proc …) lis) (bind/box box proc …) ≡ (apply/mv (compose-left proc …) (unbox box)) (bind obj proc …) ≡ ((compose-left proc …) obj)
Next: srfi.215
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