Nelumbo

Nelumbo aims to be a powerful and extensible declarative logic programming language, designed for defining and executing custom syntax and semantics. As a meta-language, Nelumbo will be easily extensible, making it suitable for a wide range of applications. The goal is to integrate it with any IDE using the Language Server Protocol, allowing Nelumbo to serve as a language development platform. The language is currently developed in Java for seamless integration and performance. Please note that Nelumbo is in a very early stage of development, and incompatible changes are likely to occur.

---

Table of Contents

• Features
• Examples
• Contributing
• License
• Support

---

Features

• Define and parse syntaxes
• Define and execute semantics
• Purely declarative semantics
• Define and run tests
• Easily extensible
• Easily integrable
• Written in Java

Examples

Family Relations Example

<Person>    :: <Node>
<Male>      :: <Person>
<Female>    :: <Person>

<Relation>  ::= pc(<Person>,<Person>)   // parent-child

<Person>    ::= p(<Person>),   // parent
                c(<Person>),   // child
                a(<Person>),   // ancestor
                d(<Person>),   // descendant
                m(<Person>),   // mother
                f(<Person>)    // father

<Person> a, b, c
<Male>   y
<Female> x
           
c(a)=b  <=>  pc(a,b)
p(a)=b  <=>  pc(b,a)
m(a)=b  <=>  E[x](c(x)=a & b=x)
f(a)=b  <=>  E[y](c(y)=a & b=y)

a(a)=b  <=>  d(b)=a
d(a)=c  <=>  c(a)=c |
             E[b](d(a)=b & c(b)=c)

<Male>   ::= Hendrik, Bernhard, Claus, Willem
<Female> ::= Wilhelmina, Juliana, Beatrix, Maxima, Amalia

pc(Hendrik, Juliana)
pc(Wilhelmina, Juliana)
pc(Juliana, Beatrix)
pc(Bernhard, Beatrix)
pc(Beatrix, Willem)
pc(Claus, Willem)
pc(Willem, Amalia)
pc(Maxima, Amalia)

a(Amalia)=a         ? [(a=Beatrix),(a=Maxima),(a=Hendrik),(a=Bernhard),(a=Juliana),(a=Claus),(a=Willem),(a=Wilhelmina)][..]    
m(Amalia)=Maxima    ? [()][]
m(Amalia)=Willem    ? [][()]
m(Amalia)=a         ? [(a=Maxima)][..]
f(Amalia)=a         ? [(a=Willem)][..]
f(m(f(Amalia)))=a   ? [(a=Bernhard)][..]

Fibonacci Example

<Integer> ::= fib(<Integer>)

<Integer> n, f

fib(n)=f <=> f=n                 if n<=1,
             f=fib(n-1)+fib(n-2) if n>1  

fib(0)=f       ? [(f=0)][..]
fib(1)=f       ? [(f=1)][..]
fib(5)=f       ? [(f=5)][..]
fib(100)=f     ? [(f=36#22r8fozas3n8w3)][..]
fib(1000)=f    ? [(f=36#18nrvsuayughau0blk8aylvbyaqwiaqba77rdsgscn5hzwgbgaws8i8svp4xdmoo82plxiyogd5iaj1cspez8zfeio92a76t9n1frssxklr92wyyxm8r903o1ofgncikuggcwnf)][..]

    

Contributing

Contributions and feedback are welcome! Please open issues or pull requests on GitHub.

License

This project is licensed under the terms of the LICENSE file provided in the repository.

Support

For questions or support, please use the GitHub Issues page.