Pep and Nom

the ℕ𝕠𝕞 "lines" command

Append the number of lines read to the workspace buffer

The lines (or ll*, it's original, cryptic name) command appends to the workspace the current value of the line counter register. This is very useful when writing compilers/transpilers/tranlators etc in order to produce an error message with a line number when there is a syntax or format error in the input stream.

    read;
    [#@&!*] {
      clear; 
      add "! Gurgle syntax error: "; lines; add "\n";
      add "! The characters #,@,&,!,* are very bad. End of story.\n";
      add "! Go back to the drawing board. Goodbye. \n"; 
      print; quit;
    }
    clear;
  

notes

You can set the lines register in the ℙ𝕖𝕡 virtual machine to zero with the nolines command but I don’t use this very much. The chars command is analogous to the line command but is an automatic character counter. I find the nochars command, which sets the chars register to zero, to be more useful because it allows you to make the character counter relative to the start of the current line.

    read; [\n] { nochars; }
    "&" {
      put; clear; 
      add "! on line "; lines; add " (char "; chars; add ")\n";
      add "  you used an Ampersand(&). Please Dont. Thanks.\n";
      print; clear; quit;
    }
    clear;
  

see also

chars : just likes lines but for characters.
the lines : register in the virtual machine