[ V{ 4 5 } ] [ { 1 2 3 4 5 } 2 tail-slice* >vector ] unit-test
[ V{ 3 4 } ] [ 2 4 1 10 dup <slice> subseq >vector ] unit-test
[ V{ 3 4 } ] [ 0 2 2 4 1 10 dup <slice> <slice> subseq >vector ] unit-test
+[ 0 10 "hello" <slice> ] must-fail
+[ -10 3 "hello" <slice> ] must-fail
+[ 2 1 "hello" <slice> ] must-fail
+
[ "cba" ] [ "abcdef" 3 head-slice reverse ] unit-test
[ 5040 ] [ [ 1 2 3 4 5 6 7 ] 1 [ * ] reduce ] unit-test
: check-slice ( from to seq -- from to seq )
3dup
[ 2drop 0 < "start < 0" slice-error ]
- [ nip length > "end > sequence" slice-error ]
- [ drop > "start > end" slice-error ] 3tri ; inline
+ [ [ drop ] 2dip length > "end > sequence" slice-error ]
+ [ drop > "start > end" slice-error ]
+ 3tri ; inline
: <slice> ( from to seq -- slice )
dup slice? [ collapse-slice ] when