Macro tylisp::sexpr

macro_rules! sexpr {
    { $(;)? } => { ... };
    { ; { $($head:tt)* } } => { ... };
    { ; @ {$($head:tt)*} $(= $val:expr)? } => { ... };
    { ; @ $head:ty $(= $val:expr)? } => { ... };
    { ; $head:ty } => { ... };
    { { $($head:tt)* } ; $($tail:tt)+ } => { ... };
    { @ {$($head:tt)*} $(= $val:expr)? ; $($tail:tt)+ } => { ... };
    { @ $head:ty $(= $val:expr)?; $($tail:tt)+ } => { ... };
    { $head:ty ; $($tail:tt)+ } => { ... };
    { { $($head:tt)* } $(, $($tail:tt)*)? } => { ... };
    { @ {$($head:tt)*} $(= $val:expr)? $(, $($tail:tt)*)? } => { ... };
    { @ $head:ty $(= $val:expr)? $(, $($tail:tt)*)? } => { ... };
    { $head:ty $(, $($tail:tt)*)? } => { ... };
}

sexprs, the building blocks of everything Lisp

This crate uses an unusal sexpression syntax in order to be Rust-compatible:

• Curly braces {} are used for delimiters instead of parentheses
• Terms are separated by commas instead of whitespace
• The quote character is @
• Atoms are arbitrary Rust types
• The final comma can be replaced by ; to suppress the automatic HNil