chickadee » basic-sequences

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Fundamental sequence operations

This module provides the minimum necessary to handle linear container datatypes under a common sequence interface. It's written primary to be used in the bindings egg but secondary to be extendable to a full-fledged sequence package.

Documentation

basic-sequences

basic-sequences sym ..procedure

documentation procedure. Shows the exported symbols and the syntax of such an exported symbol, respectively.

seq-exception

seq-exception loc msg #!rest argsprocedure

generates a composite condition of type (exn sequence) with location loc, message msg and arguments args.

seq-ref

seq-ref seq nprocedure

returns the nth item of the generic sequence seq

seq-tail

seq-tail seq nprocedure

returns the tail of the generic sequence seq, starting at n

seq-car

seq-car seqprocedure

returns the zeroth item of the generic sequence seq

seq-cdr

seq-cdr seqprocedure

returns the tail of the generic sequence seq, starting at 1

seq?

seq? xprprocedure

checks, if xpr is a sequence

seq-null?

seq-null? seqprocedure

checks, if seq is empty.

seq-random-access?

seq-random-access? seqprocedure

checks, if seq is randomly accessible

seq-db

seq-dbprocedure

shows the sequence database

(seq-db type? ref: ref tail: tail maker: maker ra?: random-access?)procedure

adds a new custom sequence type with predicate type? and keyword arguments ref: tail: maker: ra?: naming procedures to be later accessed as seq-ref, seq-tail, seq-maker and seq-randoam-access? respectively.

Convenience procedures

cons*

cons* arg ....procedure

iterative version of cons

list-of

list-of ok? ...procedure

returns a predicate which checks, if its argument is a list which passes every predicate ok? ...

pseudo-list-of

pseudo-list-of ok? ...procedure

returns a predicate which checks, if its argument is a pseudo-list, which passes every predicate ok? ...

vector-of

vector-of ok? ...procedure

returns a predicate which checks, if its argument is a vector which passes every predicate ok? ...

tagged-vector

tagged-vector kw arg ...procedure

generates a tagged vector with keyword kw and args arg ...

tagged-vector?

tagged-vector? xprprocedure

type predicate

tagged-vector-of

tagged-vector-of ok? ...procedure

generates a tagged vector predicate which checks all of its arguments

tagged-vector-ref

tagged-vector-ref tv kprocedure

access to kth item of tagged vector tv

tagged-vector-tail

tagged-vector-tail tv kprocedure

returns a tagged subvector of tv starting at k

thunk

(thunk xpr ....)syntax

generates a thunk with body xpr ....

thunk?

thunk? xprprocedure

checks if xpr is a thunk, i.e. a nullary procedure

symbol-dispatcher

symbol-dispatcher alistprocedure

creates a documentation procedure as used in all modules of this library.

Requirements

simple-exceptions

Usage

(use simple-exceptions basic-sequences)

Examples

(require-library basic-sequences simple-tests arrays)
(import basic-sequences
        simple-tests
        (only arrays array array? array-ref array-tail array->list))

(seq-db array? ref: array-ref tail: array-tail maker: array ra?: #t)
(define lst '(0 1 2 3 4))
(define pls '(0 1 2 3 . 4))
(define vec #(0 1 2 3 4))
(define arr (array 0 1 2 3 4))
(define str "01234")
(seq-ref lst 3) ;-> 3
(seq-ref pls 3) ; -> 3
(seq-tail pls 4) ; -> 4
(seq-ref vec 3) ; -> 3
(seq-ref arr 3) ; -> 3
(seq-ref str 3) ; -> #\3
(seq-tail lst 3) ; -> '(3 4)
(seq-tail pls 3) ; -> '(3 . 4)
(seq-tail vec 3) ; -> #(3 4)
(array->list (seq-tail arr 3)) ; -> '(3 4)
(seq-tail str 3) ; -> "34"
(seq-null? (seq-tail lst 5)) ; -> #t
(seq-null? (seq-tail vec 5)) ; -> #t
(seq-null? (seq-tail arr 5)) ; -> #t
(seq-null? (seq-tail str 5)) ; -> #t
(seq-null? (seq-tail pls 4)) ; -> #t
(seq? lst) ; -> #t
(seq? pls) ; -> #t
(seq? vec) ; -> #t
(seq? str) ; -> #t
(seq? arr) ; -> #t
((seq-of integer? odd?) arr) ; -> #f
((seq-of integer? odd?) #(1 3 5 7)) ; -> #t
(seq-maker lst) ; -> list
(seq-maker pls) ; -> cons*
(seq-maker vec) ; -> vector
(seq-random-access? arr) ; -> #t
(seq-random-access? vec) ; -> #t
(seq-random-access? lst) ; -> #f
(cons* 0 1 2 3) ; -> '(0 1 2 . 3)
(thunk? (thunk 1 2 3)) ; -> #t
(define tv (tagged-vector x: 0 1 2 3))
(tagged-vector-ref tv 0) ; -> x:
(define null (tagged-vector x:))
(tagged-vector? null) ; -> #t
(seq? null) ; -> #t
(seq-null? null) ; -> #f
(define tv3 (tagged-vector-tail tv 3))
(tagged-vector-ref tv3 0) ; -> x:
(define tv4 (tagged-vector-tail tv 4))
(tagged-vector? tv4) ; -> #t
(seq-null? tv4) ; -> #f
(define tv5 (tagged-vector-tail tv 5))
(seq-null? tv5) ; -> #t
(condition-case (tagged-vector-ref tv5 0)
  ((exn sequence) #f)) ; -> #f

Last update

Jul 12, 2018

Author

Juergen Lorenz

License

Copyright (c) 2011-2018, Juergen Lorenz
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
Neither the name of the author nor the names of its contributors may be
used to endorse or promote products derived from this software without
specific prior written permission. 
  
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Version History

2.2 ; fixed the bugfix

2.1 ; bug in tagged-vector? fixed, thanks to Martin Schneeweis

2.0 ; tagged vectors added to be used with algebraic types

1.0

initial import