#[macro_export]
macro_rules! lexer {
([[$token_type:ident] $lext:ident, $current:ident $(, $label:tt)?] else $no_match:expr; token_types {$($variant:ident$(($varin_name:ident: $varin_type:ty))? => $fmt:expr;)*} $($first:tt$sep:tt$second:tt;)*) => {
#[derive(Debug, Clone, PartialEq)]
pub enum $token_type {
$($variant$(($varin_type))?),*
}
impl std::fmt::Display for $token_type {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
$(Self::$variant$(($varin_name))? => write!(f, "{}", $fmt)),*
}
}
}
impl $token_type {
pub fn tokenize(mut $lext: $crate::lext::Lext) -> Box<[$crate::token_node::Token<Self>]> {
let mut tokens = Vec::<$crate::token_node::Token<Self>>::new();
$($label:)? while let Some($current) = $lext.current {
tokens.push('code: {
$($crate::lexer!(@sect $lext 'code $current $first$sep$second);)*
$no_match
});
$lext.cursor.pos_start = $lext.cursor.pos_end.clone(); } tokens.into_boxed_slice()
}
}
};
(@sect $lext:ident $label:tt $current:ident $out:ident: ($($tail:tt)*)) => {{ let mut child = $lext.spawn();
$crate::lexer!(@recur-sect1 $label $out $lext child $($tail)*);
}};
(@sect $lext:ident $label:tt $current:ident $name:ident: $char:tt) => {
if $crate::lexer!(@value $current $char) {
use $crate::flext::Flext;
$lext.advance();
break $label $crate::token_node::Token {
position: $lext.rposition(),
token_type: Self::$name,
};
}
};
(@sect $lext:ident $label:tt $current:ident $start:tt $child:ident {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
if $crate::lexer!(@value $current $start) {
use $crate::flext::Flext;
let mut $child = $lext.spawn();
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
}
};
(@sect $lext:ident $label:tt $current:ident $char:tt >> ($action:expr)) => {
if $crate::lexer!(@value $current $char) {
$action;
}
};
(@recur-sect1 $label:tt $out:ident $lext:ident $child:ident $char:tt) => {
if let Some(current) = $child.current {
if $crate::lexer!(@value current $char) {
$lext = $child.clone();
$lext.advance();
break $label $crate::token_node::Token {
position: $lext.rposition(),
token_type: Self::$out,
};
}
}
};
(@recur-sect1 $label:tt $out:ident $lext:ident $child:ident $char:tt $($tail:tt)*) => {
if let Some(current) = $child.current {
if $crate::lexer!(@value current $char) {
$child.advance();
$crate::lexer!(@recur-sect1 $label $out $lext $child $($tail)*);
}
}
};
(@det $child:ident $lext:ident $label:tt ck ($current:ident, $val:tt) {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
if $crate::lexer!(@value $current $val) {
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
}
};
(@det $child:ident $lext:ident $label:tt if ($condition:expr) {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
if $condition {
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
}
};
(@det $child:ident $lext:ident $label:tt scope $name:ident {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
{
let mut $name = $child.spawn();
$name.advance();
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
}
};
(@det $child:ident $lext:ident $label:tt done $var:ident ($($spec:expr)?)) => {
$lext = $child.clone();
break $label $crate::token_node::Token {
position: $lext.rposition(),
token_type: Self::$var$(($spec))?,
};
};
(@det $child:ident $lext:ident $label:tt update: ()) => {
$lext = $child.clone();
};
(@det $child:ident $lext:ident $label:tt advance: $current:ident) => {
$child.advance();
let $current = $child.current.unwrap_or(' ');
};
(@det $child:ident $lext:ident $label:tt advance: ()) => {
$child.advance();
};
(@det $child:ident $lext:ident $label:tt set $var:ident $val:expr) => {
let mut $var = $val;
};
(@det $child:ident $lext:ident $label:tt mut $var:ident $val:expr) => {
$var = $val;
};
(@det $child:ident $lext:ident $label:tt throw $err:ident ($position:expr $(,$spec:tt)?)) => {
let _: () = $crate::compiler_error!(($err, $position) $($spec)?).throw();
};
(@det $child:ident $lext:ident $label:tt rsome $current:ident {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
while let Some($current) = $child.current {
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
$child.advance();
}
};
(@det $child:ident $lext:ident $label:tt rsome ($current:ident, $while_label:tt) {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
$while_label: while let Some($current) = $child.current {
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
$child.advance();
}
};
(@det $child:ident $lext:ident $label:tt some $current:ident {$($($code:block)? $($key:ident $param:tt $body:tt)?;)*}) => {
if let Some($current) = $child.current {
$(
$($crate::lexer!(@det $child $lext $label $key $param $body);)?
$($code;)?
)*
$child.advance();
}
};
(@det $child:ident $lext:ident $label:tt $invalid:ident $val:tt $var:tt) => {
compile_error!(concat!("[lexer] invalid detailed instruction `", stringify!($invalid), "`"))
};
(@value $current:ident [$val:literal]) => {
$val.contains($current)
};
(@value $current:ident $val:literal) => {
$current == $val
};
(@value $current:ident $val:tt) => {
stringify!($val).contains($current)
};
}