Improvements and WIP wc

seq.nim

@@ -1,7 +1,19 @@
 import cligen
 import common
 
-proc main(last:int, first=1, increment=1, separator="\n") =
+proc main(numbers:seq[int], separator="\n") =
+    if numbers.len < 1:
+        err "seq: missing operand"
+        quit 1
+    if numbers.len > 3:
+        err "seq: extra operand"
+        quit 1
+    let
+        last = numbers[numbers.high]
+        first = if numbers.len > 1: numbers[0]
+                else: 1
+        increment = if numbers.len == 3: numbers[1]
+                    else: 1
     var i = first
     while i <= last:
         write(stdout, i)