Pep & Nom

Fortune is like a woman: if you reject her today, do not expect to meet with her tomorrow. Napoleon

nom example scripts

This folder contains some example scripts in the NOM script language. Scripts have the file extension “.pss”. These examples can be run using the interpreter and debugger (the “pep” interpreter) or by translating to rust| dart| perl| lua| go | java | javascript| ruby | python| tcl | c and then (maybe compiling and) running.

The Pep & Nom system is currently in upheaval (may 2026) because of the arrival of syntagma* which is implemented (partially) in /tr/syntagma.pss . The shell scripts /tr/engine.lua.sh and /tr/engine.perl.sh allow the “interpretation” of syntagma scripts.

Documentation for the NOM language and PEP virtual machine is in the /doc/ folder.

The scripts which begin with ro. are solutions (or attempted solutions) to problems on the www.rosettacode.org site. For example the script ro.balanced.brackets.pss solves the balanced_brackets problem .

  pep -f eg/script.pss <inputfile>
  # or
  pep -f eg/script.pss -i <inputtext>
 

Examples can be translated into rust| dart| perl| lua| go | java | javascript| ruby | python| tcl | c by running the appropriate translation script.

   pep -f tr/translate.go.pss eg/script.pss > script.go
   go build script.go
   echo "<input>" | ./script
 

Also the script /eg/nom.to.pss will translate a script with a simple prompt.

 pep -f nom.to.pss -i 'translate script.pss to rust'

Some scripts also have self-translation (for example /eg/json.check.pss and /eg/maths.tolatex.pss and /eg/text.tohtml.pss)

some example scripts

I will probably rewrite many of these example scripts in the syntagma language, since it is much easier to read than nom.

• /tr/syntagma.pss implements the syntagma* language, which is a parsing, compiling language built on top of nom. It compiles to nom and provides an EBNF-like syntax.
• /eg/xml.parse.pss is an XML parser and error checker
• /eg/nom.reference.syntax.pss is a syntax checker for the NOM language which provides precise error messages (The grammar for begin blocks and parse> labels, needs to be updated).
• /eg/json.check.pss checks the syntax of a JSON text data file.
• /eg/text.tohtml.pss transforms a “plain-text” (minimal mark-up) document into html (this is the script that generates this website).
• /eg/chat.timeline.pss implements a (simple) chatbot with the help of a small ruby script called /eg/chat.rb
• /eg/letter.typewriter.tohtml.pss which creates a letter that looks as if it has been typed on a typewriter.
• /eg/nom.tohtml.pss which colourises nom code and formats in html.
• /eg/sed.tojava.pss transpiles a gnu SED script into the JAVA language (branch syntax with 't' etc is not supported because java has not [goto] statement )
• /eg/maths.parse.pss parses and error checks arithmetic infix expressions.
• /eg/maths.tolatex.pss transforms arithmetic, symbolic and logical expressions into printable L^AT_EX formulas.
• /eg/exp.tolisp.pss transforms an arithmetic infix expression into LISP This is a simpler and older version of the 2 scripts above
• /eg/toybnf.pss translates simple BNF type grammar rules into NOM scripts. This is the basis for a bnf style parsing and compiling language
• /eg/palindrome.pss which just recognises palindromes.
• /eg/natural.language.pss implements a limited natural language (English) parser. I plan to expand this with a better 'phrase grammar'
• /eg/tocfoot.tohtml.pss demonstrates creating a table of contents and a footer (for footnotes) and using markers in the source document to place the table of contents and footers (this uses [toc] and [foot] as markers.

naming

• .noself. in the filenames means that there is no self-translation or self-help or self-testing in the script.
• The scripts are often named for the format or language that they translate to such as text.tohtml.pss or nom.tolatex.pss
• example scripts which begin with 'chat' provide a way (a sort of chatbot) to interact with another nom script or possibly a set of nom scripts. For example /eg/chat.timeline.pss should provide a chatbot which manages interactions with /eg/timeline.tohtml.pss as well as support functions related to this script, such as uploading or downloading data, editing and so forth.

ideas for example scripts

I will probably try to do most implementation in the syntagma language in the future.

• faq formatting to html or pdf.
• dictionary or glossary formatting: A script to format a plain-test dictionary into html and L^AT_EX using a standard dictionary format.
• a drawing/animation language, /eg/quill.pss
• an app-super-language which generated code for dart/flutter.

other things