Start rewrite using query system.queries

3 files changed, 0 insertions, 789 deletions

diff --git a/src/chomp/ast/error.rs b/src/chomp/ast/error.rs
deleted file mode 100644
index 9057ec3..0000000
--- a/src/chomp/ast/error.rs
+++ /dev/null
@@ -1,52 +0,0 @@
-use super::{Expression, Lambda, NamedExpression};
-use proc_macro2::Span;
-use std::{
-    error::Error,
-    fmt::{self, Display},
-};
-
-#[derive(Debug)]
-pub enum TranslateError {
-    CallNotAFunction {
-        on: Expression,
-        span: Option<Span>,
-    },
-    WrongArgCount {
-        lambda: Lambda,
-        args: Vec<NamedExpression>,
-        span: Option<Span>,
-    },
-}
-
-impl From<TranslateError> for syn::Error {
-    fn from(e: TranslateError) -> Self {
-        let msg = e.to_string();
-        let span = match e {
-            TranslateError::CallNotAFunction { span, .. }
-            | TranslateError::WrongArgCount { span, .. } => span,
-        };
-
-        Self::new(span.unwrap_or_else(Span::call_site), msg)
-    }
-}
-
-impl Display for TranslateError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::CallNotAFunction { .. } => {
-                write!(f, "call expected a function")
-            }
-            Self::WrongArgCount { lambda, args, .. } => match (lambda.args.len(), args.len()) {
-                (1, n) => write!(f, "this function takes 1 argument but {} were supplied", n),
-                (m, _) => write!(f, "this function takes {} arguments but 1 was supplied", m),
-                (m, n) => write!(
-                    f,
-                    "this function takes {} arguments but {} were supplied",
-                    m, n
-                ),
-            },
-        }
-    }
-}
-
-impl Error for TranslateError {}
diff --git a/src/chomp/ast/mod.rs b/src/chomp/ast/mod.rs
deleted file mode 100644
index 232381a..0000000
--- a/src/chomp/ast/mod.rs
+++ /dev/null
@@ -1,325 +0,0 @@
-use std::fmt::{self, Display};
-
-use proc_macro2::Span;
-
-use super::Name;
-
-pub mod error;
-pub mod substitute;
-
-#[derive(Clone, Copy, Debug, Default, Eq, PartialEq, Hash)]
-pub struct Epsilon;
-
-pub type Literal = String;
-
-#[derive(Clone, Debug)]
-pub struct Cat {
-    pub first: Box<NamedExpression>,
-    pub rest: Vec<(Option<Span>, NamedExpression)>,
-}
-
-impl Display for Cat {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "({}", self.first)?;
-        for (_, other) in &self.rest {
-            write!(f, " . {}", other)?;
-        }
-        write!(f, ")")
-    }
-}
-
-impl PartialEq for Cat {
-    fn eq(&self, other: &Self) -> bool {
-        self.first == other.first
-            && self.rest.len() == other.rest.len()
-            && self
-                .rest
-                .iter()
-                .zip(other.rest.iter())
-                .all(|((_, me), (_, them))| me == them)
-    }
-}
-
-impl Eq for Cat {}
-
-#[derive(Clone, Debug)]
-pub struct Alt {
-    pub first: Box<NamedExpression>,
-    pub rest: Vec<(Option<Span>, NamedExpression)>
-}
-
-impl Display for Alt {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "({}", self.first)?;
-        for (_, other) in &self.rest {
-            write!(f, " | {}", other)?;
-        }
-        write!(f, ")")
-    }
-}
-
-impl PartialEq for Alt {
-    fn eq(&self, other: &Self) -> bool {
-        self.first == other.first
-            && self.rest.len() == other.rest.len()
-            && self
-                .rest
-                .iter()
-                .zip(other.rest.iter())
-                .all(|((_, me), (_, them))| me == them)
-    }
-}
-
-impl Eq for Alt {}
-
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Fix {
-    pub inner: Box<NamedExpression>,
-}
-
-impl Display for Fix {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "!{}", self.inner)
-    }
-}
-
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
-pub struct Variable {
-    pub index: usize,
-}
-
-impl Display for Variable {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "'{}", self.index)
-    }
-}
-
-/// A function invocation.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Call {
-    pub on: Box<NamedExpression>,
-    pub args: Vec<NamedExpression>,
-}
-
-impl Display for Call {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "({}", self.on)?;
-
-        for arg in self.args {
-            write!(f, " {}", arg)?;
-        }
-
-        write!(f, ")")
-    }
-}
-
-/// A function abstraction.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Lambda {
-    pub args: Vec<Name>,
-    pub inner: Box<NamedExpression>,
-}
-
-impl Display for Lambda {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "/")?;
-        let mut iter = self.args.iter();
-        if let Some(arg) = iter.next() {
-            write!(f, "{}", arg)?;
-
-            for arg in iter {
-                write!(f, ", {}", arg)?;
-            }
-        }
-        write!(f, "/ {}", self.inner)
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum Expression {
-    /// Matches the empty string.
-    Epsilon(Epsilon),
-    /// Matches the literal string.
-    Literal(Literal),
-    /// Matches one term followed by another.
-    Cat(Cat),
-    /// Matches either one term or another.
-    Alt(Alt),
-    /// The least fix point of a term.
-    Fix(Fix),
-    /// A fixed point variable.
-    Variable(Variable),
-    /// A function invocation.
-    Call(Call),
-    /// A function abstraction.
-    Lambda(Lambda),
-}
-
-impl Expression {
-    pub fn try_into_lambda(self) -> Result<Lambda, Self> {
-        if let Self::Lambda(l) = self {
-            Ok(l)
-        } else {
-            Err(self)
-        }
-    }
-}
-
-impl Display for Expression {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Epsilon(_) => write!(f, "_"),
-            Self::Literal(l) => l.fmt(f),
-            Self::Cat(c) => c.fmt(f),
-            Self::Alt(a) => a.fmt(f),
-            Self::Fix(x) => x.fmt(f),
-            Self::Variable(v) => v.fmt(f),
-            Self::Lambda(p) => p.fmt(f),
-            Self::Call(c) => c.fmt(f),
-        }
-    }
-}
-
-impl PartialEq for Expression {
-    fn eq(&self, other: &Self) -> bool {
-        match self {
-            Self::Epsilon(_) => matches!(other, Self::Epsilon(_)),
-            Self::Literal(l) => {
-                if let Self::Literal(them) = other {
-                    l == them
-                } else {
-                    false
-                }
-            }
-            Self::Cat(c) => {
-                if let Self::Cat(them) = other {
-                    c == them
-                } else {
-                    false
-                }
-            }
-            Self::Alt(a) => {
-                if let Self::Alt(them) = other {
-                    a == them
-                } else {
-                    false
-                }
-            }
-            Self::Fix(f) => {
-                if let Self::Fix(them) = other {
-                    f == them
-                } else {
-                    false
-                }
-            }
-            Self::Variable(v) => {
-                if let Self::Variable(them) = other {
-                    v == them
-                } else {
-                    false
-                }
-            }
-            Self::Lambda(p) => {
-                if let Self::Lambda(them) = other {
-                    p == them
-                } else {
-                    false
-                }
-            }
-            Self::Call(c) => {
-                if let Self::Call(them) = other {
-                    c == them
-                } else {
-                    false
-                }
-            }
-        }
-    }
-}
-
-impl Eq for Expression {}
-
-impl From<Epsilon> for Expression {
-    fn from(eps: Epsilon) -> Self {
-        Self::Epsilon(eps)
-    }
-}
-
-impl From<Literal> for Expression {
-    fn from(lit: Literal) -> Self {
-        Self::Literal(lit)
-    }
-}
-
-impl From<Cat> for Expression {
-    fn from(cat: Cat) -> Self {
-        Self::Cat(cat)
-    }
-}
-
-impl From<Alt> for Expression {
-    fn from(alt: Alt) -> Self {
-        Self::Alt(alt)
-    }
-}
-
-impl From<Fix> for Expression {
-    fn from(fix: Fix) -> Self {
-        Self::Fix(fix)
-    }
-}
-
-impl From<Variable> for Expression {
-    fn from(var: Variable) -> Self {
-        Self::Variable(var)
-    }
-}
-
-impl From<Lambda> for Expression {
-    fn from(lambda: Lambda) -> Self {
-        Self::Lambda(lambda)
-    }
-}
-
-impl From<Call> for Expression {
-    fn from(call: Call) -> Self {
-        Self::Call(call)
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct NamedExpression {
-    pub name: Option<Name>,
-    pub expr: Expression,
-    pub span: Option<Span>,
-}
-
-impl Display for NamedExpression {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match &self.name {
-            Some(name) => write!(f, "({} : {})", self.expr, name),
-            None => self.expr.fmt(f),
-        }
-    }
-}
-
-impl PartialEq for NamedExpression {
-    fn eq(&self, other: &Self) -> bool {
-        self.expr == other.expr
-    }
-}
-
-impl Eq for NamedExpression {}
-
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Let {
-    pub name: Name,
-    pub val: NamedExpression,
-    pub inner: Box<TopLevel>,
-}
-
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub enum TopLevel {
-    Let(Let),
-    Goal(NamedExpression),
-}
diff --git a/src/chomp/ast/substitute.rs b/src/chomp/ast/substitute.rs
deleted file mode 100644
index 80df588..0000000
--- a/src/chomp/ast/substitute.rs
+++ /dev/null
@@ -1,412 +0,0 @@
-use super::{
-    error::TranslateError, Alt, Call, Cat, Epsilon, Fix, Lambda, Literal, NamedExpression, Variable,
-};
-use crate::chomp::{
-    visit::{Folder, Mapper, Visitable},
-    Name,
-};
-use proc_macro2::Span;
-
-struct Deepen {
-    pub depth: usize,
-    pub by: usize,
-}
-
-impl Mapper for Deepen {
-    type Out = ();
-
-    fn map_epsilon(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        _eps: &mut Epsilon,
-    ) -> Self::Out {
-    }
-
-    fn map_literal(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        _lit: &mut Literal,
-    ) -> Self::Out {
-    }
-
-    fn map_cat(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        cat: &mut Cat,
-    ) -> Self::Out {
-        cat.first.map(self);
-        for (_, other) in &mut cat.rest {
-            other.map(self);
-        }
-    }
-
-    fn map_alt(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        alt: &mut Alt,
-    ) -> Self::Out {
-        alt.first.map(self);
-        for (_, other) in &mut alt.rest {
-            other.map(self);
-        }
-    }
-
-    fn map_fix(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        fix: &mut Fix,
-    ) -> Self::Out {
-        fix.inner.map(self);
-    }
-
-    fn map_variable(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        var: &mut Variable,
-    ) -> Self::Out {
-        if var.index >= self.depth {
-            var.index += self.by;
-        }
-    }
-
-    fn map_call(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        call: &mut Call,
-    ) -> Self::Out {
-        call.on.map(self);
-        for arg in &mut call.args {
-            arg.map(self);
-        }
-    }
-
-    fn map_lambda(
-        &mut self,
-        _name: &mut Option<Name>,
-        _span: Option<Span>,
-        lambda: &mut Lambda,
-    ) -> Self::Out {
-        self.depth += lambda.args.len();
-        lambda.inner.map(self);
-        self.depth -= lambda.args.len();
-    }
-}
-
-pub struct Substitute {
-    pub index: usize,
-    pub expr: NamedExpression,
-}
-
-impl Folder for Substitute {
-    type Out = NamedExpression;
-
-    fn fold_epsilon(&mut self, name: Option<Name>, span: Option<Span>, eps: Epsilon) -> Self::Out {
-        NamedExpression {
-            name,
-            expr: eps.into(),
-            span,
-        }
-    }
-
-    fn fold_literal(&mut self, name: Option<Name>, span: Option<Span>, lit: Literal) -> Self::Out {
-        NamedExpression {
-            name,
-            expr: lit.into(),
-            span,
-        }
-    }
-
-    fn fold_cat(&mut self, name: Option<Name>, span: Option<Span>, mut cat: Cat) -> Self::Out {
-        cat.first = Box::new(cat.first.fold(self));
-        cat.rest = cat
-            .rest
-            .into_iter()
-            .map(|(span, e)| (span, e.fold(self)))
-            .collect();
-        NamedExpression {
-            name,
-            expr: cat.into(),
-            span,
-        }
-    }
-
-    fn fold_alt(&mut self, name: Option<Name>, span: Option<Span>, mut alt: Alt) -> Self::Out {
-        alt.first = Box::new(alt.first.fold(self));
-        alt.rest = alt
-            .rest
-            .into_iter()
-            .map(|(span, e)| (span, e.fold(self)))
-            .collect();
-        NamedExpression {
-            name,
-            expr: alt.into(),
-            span,
-        }
-    }
-
-    fn fold_fix(&mut self, name: Option<Name>, span: Option<Span>, mut fix: Fix) -> Self::Out {
-        fix.inner = Box::new(fix.inner.fold(self));
-        NamedExpression {
-            name,
-            expr: fix.into(),
-            span,
-        }
-    }
-
-    fn fold_variable(
-        &mut self,
-        name: Option<Name>,
-        span: Option<Span>,
-        var: Variable,
-    ) -> Self::Out {
-        if var.index == self.index {
-            self.expr.clone()
-        } else {
-            NamedExpression {
-                name,
-                expr: Variable {
-                    index: if var.index > self.index {
-                        var.index - 1
-                    } else {
-                        var.index
-                    },
-                }
-                .into(),
-                span,
-            }
-        }
-    }
-
-    fn fold_call(&mut self, name: Option<Name>, span: Option<Span>, mut call: Call) -> Self::Out {
-        call.on = Box::new(call.on.fold(self));
-        call.args = call.args.into_iter().map(|e| e.fold(self)).collect();
-        NamedExpression {
-            name,
-            expr: call.into(),
-            span,
-        }
-    }
-
-    fn fold_lambda(
-        &mut self,
-        name: Option<Name>,
-        span: Option<Span>,
-        mut lambda: Lambda,
-    ) -> Self::Out {
-        self.index += lambda.args.len();
-        lambda.inner = Box::new(lambda.inner.fold(self));
-        self.index -= lambda.args.len();
-        NamedExpression {
-            name,
-            expr: lambda.into(),
-            span,
-        }
-    }
-}
-
-pub struct Translate {
-    changed: bool,
-}
-
-impl Translate {
-    pub fn new() -> Self {
-        Self { changed: false }
-    }
-}
-
-impl Default for Translate {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl Folder for Translate {
-    type Out = Result<NamedExpression, TranslateError>;
-
-    fn fold_epsilon(&mut self, name: Option<Name>, span: Option<Span>, eps: Epsilon) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: eps.into(),
-            span,
-        })
-    }
-
-    fn fold_literal(&mut self, name: Option<Name>, span: Option<Span>, lit: Literal) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: lit.into(),
-            span,
-        })
-    }
-
-    fn fold_cat(&mut self, name: Option<Name>, span: Option<Span>, cat: Cat) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: cat.into(),
-            span,
-        })
-    }
-
-    fn fold_alt(&mut self, name: Option<Name>, span: Option<Span>, alt: Alt) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: alt.into(),
-            span,
-        })
-    }
-
-    fn fold_fix(&mut self, name: Option<Name>, span: Option<Span>, fix: Fix) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: fix.into(),
-            span,
-        })
-    }
-
-    fn fold_variable(
-        &mut self,
-        name: Option<Name>,
-        span: Option<Span>,
-        var: Variable,
-    ) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: var.into(),
-            span,
-        })
-    }
-
-    fn fold_call(&mut self, name: Option<Name>, span: Option<Span>, call: Call) -> Self::Out {
-        let mut on = *call.on;
-        self.changed = true;
-        while self.changed {
-            self.changed = false;
-            on = on.fold(self)?;
-        }
-
-        let lambda = on
-            .expr
-            .try_into_lambda()
-            .map_err(|on| TranslateError::CallNotAFunction { on, span })?;
-
-        if lambda.args.len() != call.args.len() {
-            return Err(TranslateError::WrongArgCount {
-                lambda,
-                args: call.args,
-                span,
-            });
-        }
-
-        let mut out = *lambda.inner;
-
-        for ((i, mut arg), name) in call.args.into_iter().enumerate().zip(lambda.args).rev() {
-            arg.name = arg.name.or(Some(name));
-            arg.map(&mut Deepen { depth: 0, by: i });
-            out = out.fold(&mut Substitute {
-                index: 0,
-                expr: arg,
-            });
-        }
-
-        self.changed = true;
-        while self.changed {
-            self.changed = false;
-            out = out.fold(self)?;
-        }
-
-        self.changed = true;
-        out.name = name.or(out.name);
-        out.span = span.or(out.span);
-        Ok(out)
-    }
-
-    fn fold_lambda(&mut self, name: Option<Name>, span: Option<Span>, lambda: Lambda) -> Self::Out {
-        Ok(NamedExpression {
-            name,
-            expr: lambda.into(),
-            span,
-        })
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// Returns (/x/ x) 'index
-    fn make_expr(index: usize) -> NamedExpression {
-        let var = NamedExpression {
-            name: None,
-            expr: Variable { index: 0 }.into(),
-            span: None,
-        };
-
-        let lambda = NamedExpression {
-            name: None,
-            expr: Lambda {
-                args: vec!["x".to_owned().into()],
-                inner: Box::new(var),
-            }
-            .into(),
-            span: None,
-        };
-
-        let var = NamedExpression {
-            name: None,
-            expr: Variable { index }.into(),
-            span: None,
-        };
-
-        NamedExpression {
-            name: None,
-            expr: Call {
-                on: Box::new(lambda),
-                args: vec![var],
-            }
-            .into(),
-            span: None,
-        }
-    }
-
-    #[test]
-    fn deepen_lambda() {
-        let mut expr = make_expr(0);
-        expr.map(&mut Deepen { depth: 0, by: 1 });
-        assert_eq!(expr, make_expr(1))
-    }
-
-    #[test]
-    fn substitute_renames_bigger() {
-        let expr = make_expr(1);
-        let expr = expr.fold(&mut Substitute {
-            index: 0,
-            expr: NamedExpression {
-                name: None,
-                expr: Epsilon.into(),
-                span: None,
-            },
-        });
-        assert_eq!(expr, make_expr(0))
-    }
-
-    #[test]
-    fn translate_lambda() {
-        let expr = make_expr(1);
-        let expr = expr.fold(&mut Translate::new()).unwrap();
-        assert_eq!(
-            expr,
-            NamedExpression {
-                name: Some("x".to_owned().into()),
-                expr: Variable { index: 1 }.into(),
-                span: None
-            }
-        )
-    }
-}