Support | as the disjunction token (#64)

Author: s-arash

ascent/examples/ascent_disjunction_clause.rs

@@ -19,7 +19,7 @@ ascent! {
 
     relation even_or_square(i32);
 
-    even_or_square(x) <-- (even(x) || square(x));
+    even_or_square(x) <-- (even(x) | square(x));
 }
 
 fn main() {

ascent/src/exps.rs

@@ -1,3 +1,4 @@
+// TODO delete this file
 #![cfg(all(test, feature = "par"))]
 #![allow(dead_code)]
 

ascent_macro/src/ascent_hir.rs

@@ -520,9 +520,9 @@ pub(crate) fn prog_get_relation<'a>(
             Err(Error::new(
                name.span(),
                format!(
-                  "wrong arity for relation `{name}` (expected {expected}, found {actual})",
-                  expected = arity,
-                  actual = rel.field_types.len()
+                  "wrong arity for relation `{name}` (expected {expected}, found {found})",
+                  expected = rel.field_types.len(),
+                  found = arity, 
                ),
             ))
          } else {

ascent_macro/src/ascent_syntax.rs

@@ -177,21 +177,34 @@ fn peek_macro_invocation(parse_stream: ParseStream) -> bool {
 
 fn peek_if_or_let(parse_stream: ParseStream) -> bool { parse_stream.peek(Token![if]) || parse_stream.peek(Token![let]) }
 
+#[derive(Parse, Clone)]
+enum DisjunctionToken {
+   #[allow(unused)]
+   #[peek(Token![||], name = "||")]
+   OrOr(Token![||]),
+   #[allow(unused)]
+   #[peek(Token![|], name = "|")]
+   Or(Token![|]),
+}
+
 #[derive(Clone)]
 pub struct DisjunctionNode {
    paren: syn::token::Paren,
-   disjuncts: Punctuated<Punctuated<BodyItemNode, Token![,]>, Token![||]>,
+   disjuncts: Punctuated<Punctuated<BodyItemNode, Token![,]>, DisjunctionToken>,
 }
 
 impl Parse for DisjunctionNode {
    fn parse(input: ParseStream) -> Result<Self> {
       let content;
       let paren = parenthesized!(content in input);
-      let res: Punctuated<Punctuated<BodyItemNode, Token![,]>, Token![||]> =
-         Punctuated::<Punctuated<BodyItemNode, Token![,]>, Token![||]>::parse_terminated_with(
+      let res: Punctuated<Punctuated<BodyItemNode, Token![,]>, DisjunctionToken> =
+         Punctuated::<Punctuated<BodyItemNode, Token![,]>, DisjunctionToken>::parse_terminated_with(
             &content,
             Punctuated::<BodyItemNode, Token![,]>::parse_separated_nonempty,
          )?;
+      if res.pairs().any(|pair| matches!(pair.punct(), Some(DisjunctionToken::OrOr(_)))) {
+         eprintln!("WARNING: In Ascent rules, use `|` as the disjunction token instead of `||`")
+      }
       Ok(DisjunctionNode { paren, disjuncts: res })
    }
 }

ascent_tests/src/analysis_exp.rs

@@ -166,7 +166,7 @@ ascent! {
 
    ς(v.clone(), ρ2, a, tick(e, ρ, a, t, k)) <--
       ς(?e@Ref(x), ρ, a, t),
-      (σ(ρ[x], ?Value(v, ρ2)) ||
+      (σ(ρ[x], ?Value(v, ρ2)) |
       σnum(ρ[x], lit), let v = Lit(*lit), let ρ2 = ρ),
       σ(a, ?Kont(k));
 

ascent_tests/src/macros_tests.rs

@@ -18,7 +18,7 @@ fn test_macro_in_macro() {
       foo2(12, 11);
 
       macro foo($x: ident, $y: ident){
-         (foo1($x, $y) || foo2($x, $y)), if $x < $y,
+         (foo1($x, $y) | foo2($x, $y)), if $x < $y,
       }
 
       bar(x, y) <-- foo!(x, y);
@@ -51,7 +51,7 @@ fn test_macro_in_macro2() {
       relation res(Atomic);
 
       macro ae($x: ident) {
-         (res(?Atomic::Var(_var)), σ(_var, $x) ||
+         (res(?Atomic::Var(_var)), σ(_var, $x) |
           res(?Atomic::Val($x)))
       }
 
@@ -201,7 +201,7 @@ fn test_macro_in_macro7() {
       macro bar($x: ident, $y: expr) { bar(?Some($x), $y) }
 
       macro foo2($x: expr, $y: expr) {
-         foo!($x, $y), let x = $x, for x2 in [1, 2], ((foo(x, x2), let y = $y, let _ = println!("{}", y)) || if true, for y in [$y, $y]),
+         foo!($x, $y), let x = $x, for x2 in [1, 2], ((foo(x, x2), let y = $y, let _ = println!("{}", y)) | if true, for y in [$y, $y]),
          foo!(x + 0, y - 0), foo(x, y), foo!(x, y),
          let z = |x: i32| {x}, foo(z(*x), z(*y))
       }

ascent_tests/src/tests.rs

@@ -402,24 +402,34 @@ fn test_dl_disjunctions() {
       relation bar(i32, i32);
 
       small(x) <-- for x in 0..5;
-      foo1(0, 4);
-      foo1(1, 4);
-      foo1(2, 6);
+      foo1(0, 4); foo1(1, 4); foo1(2, 6);
 
-      foo2(3, 30);
-      foo2(2, 20);
-      foo2(8, 21);
-      foo2(9, 21);
+      foo2(3, 30); foo2(2, 20); foo2(8, 21); foo2(9, 21);
 
       bar(x.clone(), y.clone()) <-- ((for x in 3..10), small(x) || foo1(x,_y)), (foo2(x,y));
-
    };
    let mut prog = AscentProgram::default();
    prog.run();
    println!("bar: {:?}", prog.bar);
    assert_rels_eq!([(3, 30), (2, 20)], prog.bar);
 }
 
+#[test]
+fn test_dl_disjunctions2() {
+   let res = ascent_run! {
+      relation road(&'static str, &'static str);
+      relation rail(&'static str, &'static str);
+
+      road("A", "B"); road("B", "C"); rail("C", "D");
+
+      relation connected(&'static str, &'static str);
+
+      connected(x, y) <-- (road(x, y) | rail(x, y));
+      connected(x, z) <-- connected(x, y), (road(y, z) | rail(y, z));
+   };
+   assert!(res.connected.contains(&("A", "D")));
+}
+
 #[test]
 fn test_dl_repeated_vars() {
    ascent_m_par! {