Sort an outline at every level: Difference between revisions

=={{header|J}}==

Implementation:<lang J>parse2=: {{

((=<./)y (1 i.~ -.@e.)S:0 m) m {{

({.y),<m parse2^:(*@#)}.y

}};.1 y

}}

parseout=: {{

ws=. ' ',TAB

lines=: <;.2 y

indents=: lines (1 i.~ -.@e.)S:0 ws

unit=: +./indents

if. -. (-: i.@#)~.indents%unit do.

echo 'inconsistent indent widths'

end.

if. 1~:#~.;indents unit{{<(1,:m) <;._3 x{.;y }}"0 lines do.

echo 'inconsistent use of whitespace characters'

end.

ws parse2 lines

}} :.unparse

sortout=: {{ if. L.y do. u~ ({."1 y),.u sortout each}."1 y else. u~y end. }}

unparse=: {{ ;<S:0 y }}</lang>

Task examples (task data defined below):<lang J> /:sortout&.parseout sample1

alpha

epsilon

iota

theta

zeta

beta

delta

gamma

kappa

lambda

mu

\:sortout&.parseout sample1

zeta

gamma

mu

lambda

kappa

delta

beta

alpha

theta

iota

epsilon

/:sortout&.parseout sample2

alpha

epsilon

iota

theta

zeta

beta

delta

gamma

kappa

lambda

mu

/:sortout&.parseout sample3

inconsistent indent widths

inconsistent use of whitespace characters

alpha

iota

theta

zeta

beta

delta

gamma

kappa

lambda

mu

/:sortout&.parseout sample4

inconsistent indent widths

alpha

epsilon

iota

theta

zeta

gamma

delta

</lang>

Data for task examples:

<lang J>sample1=: {{)n

zeta

beta

gamma

lambda

kappa

mu

delta

alpha

theta

iota

epsilon

}}

sample2=:{{)n

zeta

gamma

mu

lambda

kappa

delta

beta

alpha

theta

iota

epsilon

}}

sample3=:{{)n

alpha

epsilon

iota

theta

zeta

beta

delta

gamma

kappa

lambda

mu

}}

sample4=:{{)n

zeta

beta

gamma

lambda

kappa

mu

delta

alpha

theta

iota

epsilon

}}</lang>