cmc/learn

 1import os, strutils, terminal
 2
 3proc readLines(path: string): seq[string] =
 4  result = @[]
 5  for line in lines(path):
 6    result.add(line)
 7
 8proc diffFiles(fileA, fileB: string) =
 9  let
10    linesA = readLines(fileA)
11    linesB = readLines(fileB)
12
13  var
14    i = 0
15    j = 0
16
17  while i < linesA.len or j < linesB.len:
18    if i < linesA.len and j < linesB.len:
19      if linesA[i] == linesB[j]:
20        echo linesA[i]  # identical, no color
21        i.inc
22        j.inc
23      else:
24        setForegroundColor(fgRed)
25        echo "- ", linesA[i]
26        resetAttributes()
27        setForegroundColor(fgGreen)
28        echo "+ ", linesB[j]
29        resetAttributes()
30        i.inc
31        j.inc
32    elif i < linesA.len:
33      setForegroundColor(fgRed)
34      echo "- ", linesA[i]
35      resetAttributes()
36      i.inc
37    elif j < linesB.len:
38      setForegroundColor(fgGreen)
39      echo "+ ", linesB[j]
40      resetAttributes()
41      j.inc
42
43when isMainModule:
44  if paramCount() != 2:
45    echo "Usage: colordiff <file1> <file2>"
46    quit(1)
47  diffFiles(paramStr(1), paramStr(2))