Pep and Nom

the ℕ𝕠𝕞 "restart" command

restart the script from the beginning

The “.restart” command makes the interpreter jump beginning of of the script, or just after the begin block if there is one.

It is important to realise that the is an implicit .restart at the end of all nom scripts . This behaviour mirrors the behaviour of SED and AWK which also jump back to the beginning of the script while there is more input to be read

The .restart command takes no arguments, and is not terminated with a semi-colon. I chose this syntax for .restart and .reparse because it emphasises that the script execution does not continue past that point.

notes

In non parsing scripts such as the nom html pretty-printer /eg/nom.tohtml.pss and the snippet pretty-printer /eg/nom.snippet.tohtml.pss this command is used instead of .reparse

At the end of the input stream a .restart command will jump straight back to the 1^st command after the begin block which is usually a read command. In this case the script will just silently exit because read at the EOF automatically exits the script. This may not be what you want. The script below shows a pattern for trapping .restart commands at the end of the input.

    begin { add "hello"; print; clear; }
    (eof) {
      add "goodbye!"; print; quit;
    } 
    read;
    # ignore space and jump back to the start of the script
    [:space:] { clear; .restart }
    # do stuff here
  

see also

.reparse