examples/rosettacode/align_columns.nit

   1 #!/usr/bin/env nit
   2 #
   3 # This file is part of NIT ( http://www.nitlanguage.org ).
   4 # This program is public domain
   5
   6 # Task: Align columns
   7 # SEE: <http://rosettacode.org/wiki/Align_columns>
   8 #
   9 # Uses `Text::justify` from the standard library.
  10 module align_columns
  11
  12 fun aligner(text: String, left: Float)
  13 do
  14         # Each row is a sequence of fields
  15         var rows = new Array[Array[String]]
  16         for line in text.split('\n') do
  17                 rows.add line.split("$")
  18         end
  19
  20         # Compute the final length of each column
  21         var lengths = new Array[Int]
  22         for fields in rows do
  23                 var i = 0
  24                 for field in fields do
  25                         var fl = field.length
  26                         if lengths.length <= i or fl > lengths[i] then
  27                                 lengths[i] = fl
  28                         end
  29                         i += 1
  30                 end
  31         end
  32
  33         # Process each line and align each field
  34         for fields in rows do
  35                 var line = new Array[String]
  36                 var i = 0
  37                 for field in fields do
  38                         line.add field.justify(lengths[i], left)
  39                         i += 1
  40                 end
  41                 print line.join(" ")
  42         end
  43 end
  44
  45 var text = """
  46 Given$a$text$file$of$many$lines,$where$fields$within$a$line$
  47 are$delineated$by$a$single$'dollar'$character,$write$a$program
  48 that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
  49 column$are$separated$by$at$least$one$space.
  50 Further,$allow$for$each$word$in$a$column$to$be$either$left$
  51 justified,$right$justified,$or$center$justified$within$its$column."""
  52
  53 aligner(text, 0.0)
  54 aligner(text, 1.0)
  55 aligner(text, 0.5)