Not() function

The not() function acts as a logical NOT. If the pattern argument of the function matches, the not() function returns failure to the match. When the argument does not match, the not() function returns a successful match. The starting point does not advance when the not() function is used.

For example, the following script looks for input strings that do not contain the word horse.

• If the word horse is found in the input string, the peek() function matches but the not() function returns a failed match. In this case, the rule GETLINE does not execute.

• If the peek() function does not match, the not() function returns a successful match so the rule GETLINE executes.

  ASL Script (not_match.asl):
  START {
   not(peek(..'horse'))
   GETLINE
  }
  GETLINE{
   a:rep(word) eol
  }
  do {
   print("No horse: ".a);
  }
  DEFAULT {
   ..eol
  }
  do {
   print("Failed match");
  }
  Input (not_match.txt):
  moose horse camel
  elephant mule camel
  goat llama horse
  horse goat llama
  Output:
  $ sm_adapter --file=not_match.txt not_match.asl
  Failed match
  No horse: elephant mule camel
  Failed match
  Failed match
  $