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#[derive(PartialEq, Eq)]
pub struct Syntax {
pub name: &'static str,
pub values: Expr,
}
impl Syntax {
fn as_rhs(&self) -> String {
match &self.values {
Expr::Symbol(_) => format!("{:?}", self.values),
Expr::And(vec) => {
if vec.len() == 1 {
format!("{:?}", vec[0])
}
else {
format!("<{}>", self.name)
}
}
Expr::Or(vec) => {
if vec.len() == 1 {
format!("{:?}", vec[0])
}
else {
format!("<{}>", self.name)
}
}
Expr::Not(syntax) | Expr::Many(syntax) => {
syntax.as_rhs()
}
}
}
}
impl ::std::fmt::Debug for Syntax {
fn fmt(
&self,
f: &mut std::fmt::Formatter<'_>,
) -> std::fmt::Result {
write!(f, "{} ::= {:?}", self.name, self.values)?;
Ok(())
}
}
#[derive(PartialEq, Eq)]
pub enum Expr {
Symbol(Option<&'static str>),
And(Vec<Syntax>),
Or(Vec<Syntax>),
Not(Box<Syntax>),
Many(Box<Syntax>),
}
impl ::std::fmt::Debug for Expr {
fn fmt(
&self,
f: &mut std::fmt::Formatter<'_>,
) -> std::fmt::Result {
match self {
Self::Symbol(symbol) => match symbol {
Some(symbol) => {
::std::fmt::Debug::fmt(symbol, f)
}
None => write!(f, "*"),
},
Self::And(syntaxes) => {
// Create hashmap of keys and
// representations
for (count, syntax) in
syntaxes.iter().enumerate()
{
if count > 0 {
write!(f, " && ")?;
}
write!(f, "[{}]", syntax.as_rhs())?;
}
Ok(())
}
Self::Or(syntaxes) => {
// Create hashmap of keys and
// representations
for (count, syntax) in
syntaxes.iter().enumerate()
{
if count > 0 {
write!(f, " || ")?;
}
write!(f, "[{}]", syntax.as_rhs())?;
}
Ok(())
}
Self::Not(syntax) => {
write!(f, "![{}]", syntax.as_ref().as_rhs())
}
Self::Many(syntax) => {
write!(f, "?[{}]", syntax.as_ref().as_rhs())
}
}
}
}
#[test]
fn debug_syntax() {
let test = Syntax {
name: "Test",
values: Expr::Symbol(Some("hi")),
};
let symbol = Syntax {
name: "Array",
values: Expr::Or(
[
Syntax {
name: "Test",
values: Expr::Symbol(Some("hi")),
},
Syntax {
name: "Any",
values: Expr::Symbol(None),
},
]
.into(),
),
};
let symbol = Syntax {
name: "Compound",
values: Expr::And(
[
Syntax {
name: "Test",
values: Expr::Symbol(Some(
"aagfasfasdfsdf",
)),
},
symbol,
Syntax {
name: "Multiple",
values: Expr::Not(test.into()),
},
]
.into(),
),
};
println!("{symbol:#?}");
}