44 lines
1.3 KiB
Factor
44 lines
1.3 KiB
Factor
! Copyright (C) 2004, 2005 Slava Pestov.
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! See http://factor.sf.net/license.txt for BSD license.
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USING: errors generic kernel kernel-internals lists math
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math-internals sequences ;
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IN: vectors
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: empty-vector ( len -- vec )
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#! Creates a vector with 'len' elements set to f. Unlike
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#! <vector>, which gives an empty vector with a certain
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#! capacity.
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dup <vector> [ set-length ] keep ;
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: >vector ( list -- vector )
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dup length <vector> [ swap nappend ] keep ;
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M: vector clone ( vector -- vector )
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>vector ;
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: vector-project ( n quot -- vector )
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#! Execute the quotation n times, passing the loop counter
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#! the quotation as it ranges from 0..n-1. Collect results
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#! in a new vector.
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>r 0 swap <range> >vector r> map ; inline
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: zero-vector ( n -- vector )
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[ drop 0 ] vector-project ;
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: vector-tail ( n vector -- list )
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#! Return a new list with all elements from the nth
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#! index upwards.
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2dup length swap - [
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pick + over nth
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] project 2nip ;
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: vector-tail* ( n vector -- list )
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#! Unlike vector-tail, n is an index from the end of the
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#! vector. For example, if n=1, this returns a vector of
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#! one element.
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[ length swap - ] keep vector-tail ;
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M: general-list thaw >vector ;
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M: general-list freeze drop >list ;
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