Finish AutoChomp

1 files changed, 531 insertions, 0 deletions

diff --git a/autochomp/src/nibble.rs b/autochomp/src/nibble.rs
index 657a20f..ebe18a6 100644
--- a/autochomp/src/nibble.rs
+++ b/autochomp/src/nibble.rs
@@ -1,3 +1,13 @@
+use std::convert::TryInto;
+
+use chomp::{
+    chomp::{
+        ast::{self, Alt, Call, Cat, Fix, Function, NamedExpression, Parameter, Variable},
+        Name,
+    },
+    nibble::convert::{Binding, Context, Convert, ConvertError},
+};
+
 chomp_macro::nibble! {
     let opt(x) = _ : None | x : Some;
     let plus(x) = [plus]((x : First) . (opt(plus) : Next));
@@ -75,3 +85,524 @@ chomp_macro::nibble! {
 
     match star_(star_(goal : Goal, let : Let), Pattern_Whitespace);
 }
+
+impl Ast {
+    pub fn convert(self) -> Result<(Vec<Function>, NamedExpression), ConvertError> {
+        let content = Star2::from(self.0);
+        let mut names = Vec::new();
+        let mut map = Vec::new();
+
+        let mut iter = content.into_iter();
+
+        for stmt in &mut iter {
+            let name: Name = stmt.ident1.into();
+            let params = Option::from(stmt.opt2)
+                .into_iter()
+                .flat_map(List2::into_iter)
+                .map(Name::from);
+            let mut context = Context::new(&names, params.clone());
+            let mut expr = stmt.expr1.convert(&mut context)?;
+            names.push(name.clone());
+            expr.name = Some(name.clone());
+            map.push(Function {
+                name,
+                params: params.map(Some).collect(),
+                expr,
+                span: None,
+            });
+        }
+
+        let mut context = Context::new(&names, Vec::new());
+        let goal = iter.consume().expr1.convert(&mut context)?;
+
+        Ok((map, goal))
+    }
+}
+
+impl Convert for Expr1 {
+    fn convert(self, context: &mut Context) -> Result<NamedExpression, ConvertError> {
+        let mut iter = self.0.into_iter();
+        let first = iter.next().unwrap().convert(context)?;
+        let rest = iter
+            .map(|term| Ok((None, term.convert(context)?)))
+            .collect::<Result<Vec<_>, _>>()?;
+
+        let mut iter = rest.into_iter();
+        if let Some((punct, second)) = iter.next() {
+            Ok(NamedExpression {
+                name: None,
+                expr: Alt {
+                    first: Box::new(first),
+                    punct,
+                    second: Box::new(second),
+                    rest: iter.collect(),
+                }
+                .into(),
+                span: None,
+            })
+        } else {
+            Ok(first)
+        }
+    }
+}
+
+impl Convert for First1 {
+    fn convert(self, context: &mut Context) -> Result<NamedExpression, ConvertError> {
+        let named = self.punctuated1.convert(context)?;
+        let name = Option::from(self.opt1).or(named.name);
+
+        Ok(NamedExpression {
+            name,
+            expr: named.expr,
+            span: named.span,
+        })
+    }
+}
+
+impl Convert for Punctuated2 {
+    fn convert(self, context: &mut Context) -> Result<NamedExpression, ConvertError> {
+        let mut iter = self.into_iter();
+        let first = iter.next().unwrap().convert(context)?;
+        let rest = iter
+            .map(|term| Ok((None, term.convert(context)?)))
+            .collect::<Result<Vec<_>, _>>()?;
+
+        let mut iter = rest.into_iter();
+        if let Some((punct, second)) = iter.next() {
+            Ok(NamedExpression {
+                name: None,
+                expr: Cat {
+                    first: Box::new(first),
+                    punct,
+                    second: Box::new(second),
+                    rest: iter.collect(),
+                }
+                .into(),
+                span: None,
+            })
+        } else {
+            Ok(first)
+        }
+    }
+}
+
+impl Convert for Term1 {
+    fn convert(self, context: &mut Context) -> Result<NamedExpression, ConvertError> {
+        match self {
+            Self::Epsilon1(_) => Ok(NamedExpression {
+                name: None,
+                expr: ast::Epsilon.into(),
+                span: None,
+            }),
+            Self::Literal1(l) => Ok(NamedExpression {
+                name: None,
+                expr: l.value().into(),
+                span: None,
+            }),
+            Self::Parens1(p) => p.parens1.expr1.convert(context),
+            Self::Fix1(f) => f.fix1.convert(context),
+            Self::CallOrVariable1(c) => c.convert(context),
+        }
+    }
+}
+
+impl Convert for Fix1 {
+    fn convert(self, context: &mut Context) -> Result<NamedExpression, ConvertError> {
+        let arg = self.ident1.into();
+        let expr = *self.parens1.expr1;
+        let inner = context.with_variable(&arg, |context| expr.convert(context))?;
+
+        Ok(NamedExpression {
+            name: None,
+            expr: Fix {
+                arg: Some(arg),
+                inner: Box::new(inner),
+            }
+            .into(),
+            span: None,
+        })
+    }
+}
+
+impl Convert for CallOrVariable1 {
+    fn convert(self, context: &mut Context) -> Result<NamedExpression, ConvertError> {
+        let name = self.ident1.into();
+
+        match self.opt2 {
+            Opt26::None1(_) => {
+                let binding = context
+                    .lookup(&name)
+                    .ok_or_else(|| ConvertError::UndeclaredName(name.clone()))?;
+
+                Ok(match binding {
+                    Binding::Variable(index) => NamedExpression {
+                        name: Some(name),
+                        expr: Variable { index }.into(),
+                        span: None,
+                    },
+                    Binding::Parameter(index) => NamedExpression {
+                        name: Some(name),
+                        expr: Parameter { index }.into(),
+                        span: None,
+                    },
+                    Binding::Global => NamedExpression {
+                        name: None,
+                        expr: Call {
+                            name,
+                            args: Vec::new(),
+                        }
+                        .into(),
+                        span: None,
+                    },
+                })
+            }
+            Opt26::Some1(s) => {
+                let args = s
+                    .list1
+                    .into_iter()
+                    .map(|arg| arg.convert(context))
+                    .collect::<Result<_, _>>()?;
+                Ok(NamedExpression {
+                    name: None,
+                    expr: Call { name, args }.into(),
+                    span: None,
+                })
+            }
+        }
+    }
+}
+
+impl Literal3 {
+    pub fn value(self) -> String {
+        self.literal1
+            .plus1
+            .into_iter()
+            .map(LiteralChar1::value)
+            .collect()
+    }
+}
+
+impl LiteralChar1 {
+    pub fn value(self) -> char {
+        match self {
+            Self::Literal1(c) => c.into(),
+            Self::Escape1(e) => e.1.value(),
+        }
+    }
+}
+
+impl Alt143 {
+    pub fn value(self) -> char {
+        match self {
+            Self::Ascii1(a) => a.value(),
+            Self::Oct1(o) => o.value(),
+            Self::Unicode1(u) => u.value(),
+        }
+    }
+}
+
+impl Ascii1 {
+    pub fn value(self) -> char {
+        match self {
+            Self::Branch1(_) => '\"',
+            Self::Branch2(_) => '\'',
+            Self::Branch3(_) => '\n',
+            Self::Branch4(_) => '\r',
+            Self::Branch5(_) => '\t',
+            Self::Branch6(_) => '\\',
+            Self::Branch7(_) => '\0',
+        }
+    }
+}
+
+impl Oct1 {
+    pub fn value(self) -> char {
+        let s: String = [char::from(self.oct_digit1), char::from(self.hex_digit1)]
+            .iter()
+            .collect();
+        u32::from_str_radix(&s, 16).unwrap().try_into().unwrap()
+    }
+}
+
+impl Unicode1 {
+    pub fn value(self) -> char {
+        let s: String = [self.hex_digit1.to_string(), self.opt1.to_string()]
+            .iter()
+            .map::<&str, _>(|s| s)
+            .collect();
+        u32::from_str_radix(&s, 16).unwrap().try_into().unwrap()
+    }
+}
+
+impl IntoIterator for Punctuated1 {
+    type Item = First1;
+
+    type IntoIter = Punct1Iter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Punct1Iter(Some(self))
+    }
+}
+
+pub struct Punct1Iter(Option<Punctuated1>);
+
+impl Iterator for Punct1Iter {
+    type Item = First1;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let cat = self.0.take()?.0;
+        let first = cat.first1;
+        self.0 = cat.opt1.into();
+        Some(first)
+    }
+}
+
+impl IntoIterator for Punctuated2 {
+    type Item = Term1;
+
+    type IntoIter = Punct2Iter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Punct2Iter(Some(self))
+    }
+}
+
+pub struct Punct2Iter(Option<Punctuated2>);
+
+impl Iterator for Punct2Iter {
+    type Item = Term1;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let cat = self.0.take()?.0;
+        let term = cat.term1;
+        self.0 = cat.opt1.into();
+        Some(term)
+    }
+}
+
+impl IntoIterator for Plus2 {
+    type Item = LiteralChar1;
+
+    type IntoIter = Plus2Iter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Plus2Iter(Some(self))
+    }
+}
+
+pub struct Plus2Iter(Option<Plus2>);
+
+impl Iterator for Plus2Iter {
+    type Item = LiteralChar1;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let cat = self.0.take()?.0;
+        let lit = cat.literal_char1;
+        self.0 = cat.opt1.into();
+        Some(lit)
+    }
+}
+
+impl IntoIterator for List1 {
+    type Item = Expr1;
+
+    type IntoIter = Fix192Iter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Fix192Iter(Some(self.part3))
+    }
+}
+
+pub struct Fix192Iter(Option<Fix192>);
+
+impl Iterator for Fix192Iter {
+    type Item = Expr1;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let cat = self.0.take()?.0;
+        let expr = *cat.expr1;
+        self.0 = cat.opt1.into();
+        Some(expr)
+    }
+}
+
+impl IntoIterator for Star2 {
+    type Item = Let1;
+
+    type IntoIter = Star2Iter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Star2Iter(Some(self))
+    }
+}
+
+pub struct Star2Iter(Option<Star2>);
+
+impl Star2Iter {
+    pub fn consume(self) -> Goal1 {
+        let mut star = self.0.unwrap();
+
+        loop {
+            match star.0 {
+                Alt274::Step1(step) => star = *step.rec1,
+                Alt274::Goal1(goal) => return goal,
+            }
+        }
+    }
+}
+
+impl Iterator for Star2Iter {
+    type Item = Let1;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let star = self.0.take().unwrap();
+
+        // You can probably be safer about this and use `mem::swap` or similar.
+        // I cannot think of a way how, so this will do.
+        if let Alt274::Step1(step) = star.0 {
+            let stmt = step.let1;
+            self.0 = Some(*step.rec1);
+            Some(stmt)
+        } else {
+            self.0 = Some(star);
+            None
+        }
+    }
+}
+
+impl IntoIterator for List2 {
+    type Item = Ident5;
+
+    type IntoIter = Fix246Iter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Fix246Iter(Some(self.part3))
+    }
+}
+
+#[derive(Clone)]
+pub struct Fix246Iter(Option<Fix246>);
+
+impl Iterator for Fix246Iter {
+    type Item = Ident5;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let cat = self.0.take()?.0;
+        let expr = cat.first1.ident1;
+        self.0 = cat.opt1.into();
+        Some(expr)
+    }
+}
+
+impl From<Opt34> for Option<Punctuated1> {
+    fn from(o: Opt34) -> Self {
+        match o {
+            Opt34::None1(_) => None,
+            Opt34::Some1(s) => Some(*s.rec1),
+        }
+    }
+}
+
+impl From<Opt32> for Option<Name> {
+    fn from(o: Opt32) -> Self {
+        match o {
+            Opt32::None1(_) => None,
+            Opt32::Label1(l) => Some(l.ident1.into()),
+        }
+    }
+}
+
+impl From<Opt28> for Option<Punctuated2> {
+    fn from(o: Opt28) -> Self {
+        match o {
+            Opt28::None1(_) => None,
+            Opt28::Some1(s) => Some(*s.rec1),
+        }
+    }
+}
+
+impl From<Opt8> for Option<Plus2> {
+    fn from(o: Opt8) -> Self {
+        match o {
+            Opt8::None1(_) => None,
+            Opt8::Plus1(s) => Some(*s),
+        }
+    }
+}
+
+impl From<Opt24> for Option<Fix192> {
+    fn from(o: Opt24) -> Self {
+        match o {
+            Opt24::None1(_) => None,
+            Opt24::Some1(s) => match s.opt2 {
+                Opt23::None1(_) => None,
+                Opt23::Rec1(e) => Some(*e),
+            },
+        }
+    }
+}
+
+impl From<Opt45> for Option<List2> {
+    fn from(o: Opt45) -> Self {
+        match o {
+            Opt45::None1(_) => None,
+            Opt45::Some1(s) => Some(s.list1),
+        }
+    }
+}
+
+impl From<Opt43> for Option<Fix246> {
+    fn from(o: Opt43) -> Self {
+        match o {
+            Opt43::None1(_) => None,
+            Opt43::Some1(s) => match s.opt2 {
+                Opt42::None1(_) => None,
+                Opt42::Rec1(e) => Some(*e),
+            },
+        }
+    }
+}
+
+impl From<Ident3> for Name {
+    fn from(i: Ident3) -> Self {
+        i.to_string().into()
+    }
+}
+
+impl From<Ident2> for Name {
+    fn from(i: Ident2) -> Self {
+        i.to_string().into()
+    }
+}
+
+impl From<Ident1> for Name {
+    fn from(i: Ident1) -> Self {
+        i.to_string().into()
+    }
+}
+
+impl From<Ident5> for Name {
+    fn from(i: Ident5) -> Self {
+        i.to_string().into()
+    }
+}
+
+impl From<Ident4> for Name {
+    fn from(i: Ident4) -> Self {
+        i.to_string().into()
+    }
+}
+
+impl From<Alt277> for Star2 {
+    fn from(mut a: Alt277) -> Self {
+        while let Alt277::Step1(step) = a {
+            a = (*step.rec1).0;
+        }
+
+        if let Alt277::Star1(s) = a {
+            s
+        } else {
+            unreachable!()
+        }
+    }
+}