\ align columns

: split ( addr len char -- addr len1 addr len-len1 )
  >r 2dup r> scan 2swap 2 pick - ;

variable column

: for-each-line ( file len xt -- )
  >r begin #lf split r@ execute 1 /string dup 0<= until 2drop rdrop ;

: for-each-field ( line len xt -- )
  0 column !
  >r begin '$ split r@ execute 1 column +! 1 /string dup 0<= until 2drop rdrop ;

0 value num-columns

: count-columns ( line len -- )
  ['] 2drop for-each-field
  num-columns column @ max to num-columns ;
: find-num-columns ( file len -- )
  0 to num-columns
  ['] count-columns for-each-line ;

0 value column-widths

: column-width ( field len -- )
  column-widths column @ + c@
  max
  column-widths column @ + c!
  drop ;
: measure-widths ( line len -- )
  ['] column-width for-each-field ;
: find-column-widths ( file len -- )
  num-columns allocate throw to column-widths
  column-widths num-columns erase
  ['] measure-widths for-each-line ;

\ type aligned, same naming convention as standard numeric U.R, .R
: type.l ( addr len width -- )
  over -               >r type r>       spaces ;
: type.c ( addr len width -- )
  over - dup 2/ spaces >r type r> 1+ 2/ spaces ;
: type.r ( addr len width -- )
  over -        spaces    type ;

defer type.aligned

: print-field ( field len -- )
  column-widths column @ + c@ type.aligned space ;
: print-line   ( line len -- ) cr ['] print-field for-each-field ;
: print-fields ( file len -- )    ['] print-line  for-each-line ;


\ read file
s" columns.txt" slurp-file  ( file len )

\  scan once to determine num-columns
2dup find-num-columns

\  scan again to determine column-widths
2dup find-column-widths

\  print columns, once for each alignment type
' type.l is type.aligned  2dup print-fields cr
' type.c is type.aligned  2dup print-fields cr
' type.r is type.aligned  2dup print-fields cr

\ cleanup
nip free throw
column-widths free throw