▼ |  | Unstable: May Change Without Warning

1 | Guidelines for Developing unstable Libraries
2 | Automata: Compiling State Machines
3 | Bytes
4 | Contracts
5 | Converting Values to Strings
6 | Contracts for Macro Subexpressions
7 | Debugging
8 | Definitions
9 | Errors
10 | Filesystem
11 | Find
12 | Flonums
13 | Futures
14 | Functions
15 | Hash Tables
16 | Interface-Oriented Programming for Classes
17 | Lazy Require
18 | Lists
19 | Logging
20 | Mark Parameters
21 | Match
22 | Open place expressions
23 | Parameter Groups
24 | Pretty-Printing
25 | Re-Contracting Identifiers
26 | Sandbox
27 | Sequences
28 | Strings
29 | Structs
30 | Struct Printing
31 | Syntax
32 | Temporal Contracts: Explicit Contract Monitors
33 | GUI Libraries

On this page:

in-syntax
in-pairs
in-sequence-forever
sequence-lift
in-slice

Version: 5.3.1
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### 27`` Sequences

Sam Tobin-Hochstadt <samth@ccs.neu.edu>

This library is unstable; compatibility will not be maintained. See Unstable: May Change Without Warning for more information.

( require unstable/sequence )

> > procedure

> > ( in-syntax stx) → sequence?

> stx : syntax?

Produces a sequence equivalent to ( syntax->list lst).
An in-syntax application can provide better performance for syntax iteration when it appears directly in a for clause.

Example:

> > ( for/list ([x ( in-syntax #'(1 2 3))])
> x)

> '(#<syntax:2:0 1> #<syntax:2:0 2> #<syntax:2:0 3>)

> > procedure

> > ( in-pairs seq) → sequence?

> seq : sequence?

Produces a sequence equivalent to ( in-parallel ( sequence-lift car seq) ( sequence-lift cdr seq)).

> > procedure

> > ( in-sequence-forever seq val) → sequence?

> seq : sequence?
> val : any/c

Produces a sequence whose values are the elements of seq, followed by val repeated.

> > procedure

> > ( sequence-lift f seq) → sequence?

> f : procedure?
> seq : sequence?

Produces the sequence of f applied to each element of seq.

Example:

> > ( for/list ([x ( sequence-lift add1 ( in-range 10))])
> x)

> '(1 2 3 4 5 6 7 8 9 10)

> > > The subsequent bindings were added by David Vanderson.

> > procedure

> > ( in-slice length seq) → sequence?

> length : exact-positive-integer?
> seq : sequence?

Returns a sequence where each element is a list with length elements from the given sequence.

Example:

> > ( for/list ([e ( in-slice 3 ( in-range 8))]) e)
> '((0 1 2) (3 4 5) (6 7))

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