Is sed an insult to "human readbility" ?
mahmud: You will understand why Sed is concise the first time you write a lexer in C by hand. To lex a single character token you don't need any FSMs; the input character = the lookahead = all you need to recognize that token. You can use getc and ungetc to move forth and back in the input stream; the whole thing can be done with one tidy switch statement.Lex and Yacc where non-existent, or at least a luxury at one point. Volumes where devoted to tweaking grammars so the internal data structures used by lexers and parsers didn't exceed the minimum core available at the time.