Well, sorry but sed _is_ cryptic. Let me quote an exemple for you (squeezing blank lines):

>leaves a blank line at the beginning and end if there are some already.

     #!/usr/bin/sed -f

     # on empty lines, join with next 
     # Note there is a star in the regexp 
     :x 
     /^\n*$/ { 
       N
       bx
     }
     
     # now, squeeze all '\n', this can be also done by:
     # s/^\(\n\)*/\1/
     s/\n*/\
     /

As soon as you begin to use sed registers, the code becomes arcanic.

> arcanic

Arcane. Some would call it archaic too :)

> I think that stream-oriented languages are doomed to have an arcanic syntax.

> Streams are a non-trivial construction, after all.

...

> Well, sorry but sed _is_ cryptic. Let me quote an exemple for you (squeezing blank lines):

I agree with you that sed is cryptic, but I don't think that that necessarily means that stream processing languages are doomed to have an archaic syntax. I'd also agree with marvy in saying that the car and house example is very clear as to it's intent:

  STDIN | /\w+/{|word|
      /house/ {
        # when word is house
      }
      /car/ {
        # when word is car
      }
      {
        # default case
      }
    }

I'd say that's very straightforward and not arcane at all. Just because sed is arcane (it could be argued) doesn't make it a precondition for any stream language

EDITS: formatting.