add Expr type for union of BoolExpr or NumExpr

Author: anand-bala

argus-core/src/expr.rs

@@ -17,7 +17,7 @@ use crate::{ArgusResult, Error};
 
 /// All expressions that are numeric
 #[derive(Clone, Debug, PartialEq, argus_derive::NumExpr)]
-#[enum_dispatch(Expr)]
+#[enum_dispatch(AnyExpr)]
 pub enum NumExpr {
     /// A signed integer literal
     IntLit(IntLit),
@@ -54,7 +54,7 @@ impl NumExpr {
 
 /// All expressions that are evaluated to be of type `bool`
 #[derive(Clone, Debug, PartialEq, argus_derive::BoolExpr)]
-#[enum_dispatch(Expr)]
+#[enum_dispatch(AnyExpr)]
 pub enum BoolExpr {
     /// A `bool` literal
     BoolLit(BoolLit),
@@ -118,6 +118,15 @@ pub enum ExprRef<'a> {
     Num(&'a NumExpr),
 }
 
+/// An expression (either [`BoolExpr`] or [`NumExpr`])
+#[derive(Clone, Debug, derive_more::From)]
+pub enum Expr {
+    /// A reference to a [`BoolExpr`]
+    Bool(BoolExpr),
+    /// A reference to a [`NumExpr`]
+    Num(NumExpr),
+}
+
 /// Expression builder
 ///
 /// The `ExprBuilder` is a factory structure that deals with the creation of

argus-core/src/expr/bool_expr.rs

@@ -3,7 +3,7 @@
 use std::ops::{Bound, RangeBounds};
 use std::time::Duration;
 
-use super::{BoolExpr, Expr, NumExpr};
+use super::{AnyExpr, BoolExpr, NumExpr};
 
 /// Types of comparison operations
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -142,7 +142,7 @@ where
 // TODO(anand): Can I implement this within argus_derive?
 macro_rules! impl_bool_expr {
     ($ty:ty$(, $($arg:ident),* )? ) => {
-        impl Expr for $ty {
+        impl AnyExpr for $ty {
             fn is_numeric(&self) -> bool {
                 false
             }
@@ -157,7 +157,7 @@ macro_rules! impl_bool_expr {
         }
     };
     ($ty:ty, [$args:ident]) => {
-        impl Expr for $ty {
+        impl AnyExpr for $ty {
             fn is_numeric(&self) -> bool {
                 false
             }

argus-core/src/expr/iter.rs

@@ -2,19 +2,19 @@
 
 use std::collections::VecDeque;
 
-use super::{Expr, ExprRef};
+use super::{AnyExpr, ExprRef};
 
-/// Iterator that starts from some root [`Expr`] and travels down to it's leaf
+/// Iterator that starts from some root [`AnyExpr`] and travels down to it's leaf
 /// expressions.
 ///
 /// This essentially implements breadth-first search over the expression tree rooted at
-/// the given [`Expr`].
+/// the given [`AnyExpr`].
 pub struct AstIter<'a> {
     queue: VecDeque<ExprRef<'a>>,
 }
 
 impl<'a> AstIter<'a> {
-    /// Create an iterator that traverses an [`Expr`] from root to leaf.
+    /// Create an iterator that traverses an [`AnyExpr`] from root to leaf.
     pub fn new(root: ExprRef<'a>) -> Self {
         let mut queue = VecDeque::new();
         queue.push_back(root);
@@ -28,7 +28,7 @@ impl<'a> Iterator for AstIter<'a> {
     fn next(&mut self) -> Option<Self::Item> {
         let expr_ref = self.queue.pop_front()?;
 
-        let expr: &dyn Expr = match expr_ref {
+        let expr: &dyn AnyExpr = match expr_ref {
             ExprRef::Bool(expr) => expr,
             ExprRef::Num(expr) => expr,
         };

argus-core/src/expr/num_expr.rs

@@ -1,11 +1,11 @@
 //! Numeric expression types
 
-use super::{Expr, NumExpr};
+use super::{AnyExpr, NumExpr};
 
 // TODO(anand): Can I implement this within argus_derive?
 macro_rules! impl_num_expr {
     ($ty:ty$(, $($arg:ident),* )? ) => {
-        impl Expr for $ty {
+        impl AnyExpr for $ty {
             fn is_numeric(&self) -> bool {
                 true
             }
@@ -20,7 +20,7 @@ macro_rules! impl_num_expr {
         }
     };
     ($ty:ty, [$args:ident]) => {
-        impl Expr for $ty {
+        impl AnyExpr for $ty {
             fn is_numeric(&self) -> bool {
                 false
             }

argus-core/src/expr/traits.rs

@@ -4,7 +4,7 @@ use super::{BoolExpr, ExprRef, NumExpr};
 
 /// A trait representing expressions
 #[enum_dispatch]
-pub trait Expr {
+pub trait AnyExpr {
     /// Check if the given expression is a numeric expression
     fn is_numeric(&self) -> bool;
     /// Check if the given expression is a boolean expression
@@ -17,7 +17,7 @@ pub trait Expr {
 }
 
 /// Marker trait for numeric expressions
-pub trait IsNumExpr: Expr + Into<NumExpr> {}
+pub trait IsNumExpr: AnyExpr + Into<NumExpr> {}
 
 /// Marker trait for Boolean expressions
-pub trait IsBoolExpr: Expr + Into<BoolExpr> {}
+pub trait IsBoolExpr: AnyExpr + Into<BoolExpr> {}

argus-parser/src/parser.rs

@@ -1,18 +1,19 @@
 use std::{env, fmt, fs};
 
 use ariadne::{sources, Color, Label, Report, ReportKind};
-use chumsky::{input::SpannedInput, prelude::*};
+use chumsky::input::SpannedInput;
+use chumsky::prelude::*;
 
-use crate::lexer::{lexer, Span, Token};
+use crate::lexer::{lexer, Error as LexError, Span, Token};
 
 pub type Spanned<T> = (T, Span);
 
-// The type of the input that our parser operates on. The input is the `&[(Token, Span)]` token buffer generated by the
-// lexer, wrapped in a `SpannedInput` which 'splits' it apart into its constituent parts, tokens and spans, for chumsky
+// The type of the input that our parser operates on. The input is the `&[(Token,
+// Span)]` token buffer generated by the lexer, wrapped in a `SpannedInput` which
+// 'splits' it apart into its constituent parts, tokens and spans, for chumsky
 // to understand.
 type ParserInput<'tokens, 'src> = SpannedInput<Token<'src>, Span, &'tokens [(Token<'src>, Span)]>;
 
 pub fn parser<'tokens, 'src: 'tokens>(
-) -> impl Parser<'tokens, ParserInput<'tokens, 'src>, Spanned<Expr<'src>>, extra::Err<Rich<'tokens, Token<'src>, Span>>>
-       + Clone {
+) -> impl Parser<'tokens, ParserInput<'tokens, 'src>, Spanned<Expr<'src>>, LexError<'src>> + Clone {
 }