Shrink debug build times via BoxedParser

src/parse/parser.rs

@@ -170,13 +170,6 @@ where
     }
 }
 
-pub fn val<'a, Val>(value: Val) -> impl Parser<'a, Val>
-where
-    Val: Clone,
-{
-    move |_, state| Ok((value.clone(), state))
-}
-
 pub fn and_then<'a, P1, P2, F, Before, After>(parser: P1, transform: F) -> impl Parser<'a, After>
 where
     P1: Parser<'a, Before>,
@@ -190,7 +183,17 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn map<'a, P, F, Before, After>(parser: P, transform: F) -> impl Parser<'a, After>
+where
+    P: Parser<'a, Before>,
+    F: Fn(Before) -> After,
+{
+    map_impl(parser, transform)
+}
+
+#[inline(always)]
+fn map_impl<'a, P, F, Before, After>(parser: P, transform: F) -> impl Parser<'a, After>
 where
     P: Parser<'a, Before>,
     F: Fn(Before) -> After,
@@ -202,7 +205,20 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn map_with_arena<'a, P, F, Before, After>(parser: P, transform: F) -> impl Parser<'a, After>
+where
+    P: Parser<'a, Before>,
+    F: Fn(&'a Bump, Before) -> After,
+{
+    map_with_arena_impl(parser, transform)
+}
+
+#[inline(always)]
+pub fn map_with_arena_impl<'a, P, F, Before, After>(
+    parser: P,
+    transform: F,
+) -> impl Parser<'a, After>
 where
     P: Parser<'a, Before>,
     F: Fn(&'a Bump, Before) -> After,
@@ -214,7 +230,16 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn attempt<'a, P, Val>(attempting: Attempting, parser: P) -> impl Parser<'a, Val>
+where
+    P: Parser<'a, Val>,
+{
+    attempt_impl(attempting, parser)
+}
+
+#[inline(always)]
+pub fn attempt_impl<'a, P, Val>(attempting: Attempting, parser: P) -> impl Parser<'a, Val>
 where
     P: Parser<'a, Val>,
 {
@@ -229,7 +254,16 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn loc<'a, P, Val>(parser: P) -> impl Parser<'a, Located<Val>>
+where
+    P: Parser<'a, Val>,
+{
+    loc_impl(parser)
+}
+
+#[inline(always)]
+pub fn loc_impl<'a, P, Val>(parser: P) -> impl Parser<'a, Located<Val>>
 where
     P: Parser<'a, Val>,
 {
@@ -255,7 +289,16 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn zero_or_more<'a, P, A>(parser: P) -> impl Parser<'a, Vec<'a, A>>
+where
+    P: Parser<'a, A>,
+{
+    zero_or_more_impl(parser)
+}
+
+#[inline(always)]
+pub fn zero_or_more_impl<'a, P, A>(parser: P) -> impl Parser<'a, Vec<'a, A>>
 where
     P: Parser<'a, A>,
 {
@@ -280,7 +323,16 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn one_or_more<'a, P, A>(parser: P) -> impl Parser<'a, Vec<'a, A>>
+where
+    P: Parser<'a, A>,
+{
+    one_or_more_impl(parser)
+}
+
+#[inline(always)]
+pub fn one_or_more_impl<'a, P, A>(parser: P) -> impl Parser<'a, Vec<'a, A>>
 where
     P: Parser<'a, A>,
 {
@@ -384,7 +436,13 @@ fn line_too_long<'a>(attempting: Attempting, state: State<'a>) -> (Fail, State<'
 }
 
 /// A single char.
+#[cfg(not(debug_assertions))]
 pub fn char<'a>(expected: char) -> impl Parser<'a, ()> {
+    char_impl(expected)
+}
+
+#[inline(always)]
+pub fn char_impl<'a>(expected: char) -> impl Parser<'a, ()> {
     move |_arena, state: State<'a>| match state.input.chars().next() {
         Some(actual) if expected == actual => Ok(((), state.advance_without_indenting(1)?)),
         Some(other_ch) => Err(unexpected(other_ch, 0, state, Attempting::Keyword)),
@@ -393,7 +451,13 @@ pub fn char<'a>(expected: char) -> impl Parser<'a, ()> {
 }
 
 /// A hardcoded keyword string with no newlines in it.
+#[cfg(not(debug_assertions))]
 pub fn string<'a>(keyword: &'static str) -> impl Parser<'a, ()> {
+    string_impl(keyword)
+}
+
+#[inline(always)]
+pub fn string_impl<'a>(keyword: &'static str) -> impl Parser<'a, ()> {
     // We can't have newlines because we don't attempt to advance the row
     // in the state, only the column.
     debug_assert!(!keyword.contains("\n"));
@@ -497,7 +561,17 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn and<'a, P1, P2, A, B>(p1: P1, p2: P2) -> impl Parser<'a, (A, B)>
+where
+    P1: Parser<'a, A>,
+    P2: Parser<'a, B>,
+{
+    and_impl(p1, p2)
+}
+
+#[inline(always)]
+fn and_impl<'a, P1, P2, A, B>(p1: P1, p2: P2) -> impl Parser<'a, (A, B)>
 where
     P1: Parser<'a, A>,
     P2: Parser<'a, B>,
@@ -529,7 +603,17 @@ where
     }
 }
 
+#[cfg(not(debug_assertions))]
 pub fn either<'a, P1, P2, A, B>(p1: P1, p2: P2) -> impl Parser<'a, Either<A, B>>
+where
+    P1: Parser<'a, A>,
+    P2: Parser<'a, B>,
+{
+    either_impl(p1, p2)
+}
+
+#[inline(always)]
+pub fn either_impl<'a, P1, P2, A, B>(p1: P1, p2: P2) -> impl Parser<'a, Either<A, B>>
 where
     P1: Parser<'a, A>,
     P2: Parser<'a, B>,
@@ -969,3 +1053,133 @@ where
         }
     }
 }
+
+// DEBUG COMBINATORS
+//
+// These use dyn for runtime dynamic dispatch. It prevents combinatoric
+// explosions in types (and thus monomorphization, and thus build time),
+// but has runtime overhead, so we only use these in debug builds.
+
+#[cfg(debug_assertions)]
+pub struct BoxedParser<'a, Output> {
+    parser: Box<dyn Parser<'a, Output> + 'a>,
+}
+
+#[cfg(debug_assertions)]
+impl<'a, Output> BoxedParser<'a, Output> {
+    fn new<P>(parser: P) -> Self
+    where
+        P: Parser<'a, Output> + 'a,
+    {
+        BoxedParser {
+            parser: Box::new(parser),
+        }
+    }
+}
+
+#[cfg(debug_assertions)]
+impl<'a, Output> Parser<'a, Output> for BoxedParser<'a, Output> {
+    fn parse(&self, arena: &'a Bump, state: State<'a>) -> ParseResult<'a, Output> {
+        self.parser.parse(arena, state)
+    }
+}
+
+#[cfg(debug_assertions)]
+pub fn map<'a, P, F, Before, After>(parser: P, transform: F) -> BoxedParser<'a, After>
+where
+    P: Parser<'a, Before>,
+    F: Fn(Before) -> After,
+    F: 'a,
+    P: 'a,
+    Before: 'a,
+    After: 'a,
+{
+    BoxedParser::new(map_impl(parser, transform))
+}
+
+#[cfg(debug_assertions)]
+pub fn and<'a, P1, P2, A, B>(p1: P1, p2: P2) -> BoxedParser<'a, (A, B)>
+where
+    P1: Parser<'a, A>,
+    P2: Parser<'a, B>,
+    P1: 'a,
+    P2: 'a,
+    A: 'a,
+    B: 'a,
+{
+    BoxedParser::new(and_impl(p1, p2))
+}
+
+#[cfg(debug_assertions)]
+pub fn map_with_arena<'a, P, F, Before, After>(parser: P, transform: F) -> BoxedParser<'a, After>
+where
+    P: Parser<'a, Before>,
+    P: 'a,
+    F: Fn(&'a Bump, Before) -> After,
+    F: 'a,
+    Before: 'a,
+    After: 'a,
+{
+    BoxedParser::new(map_with_arena_impl(parser, transform))
+}
+
+#[cfg(debug_assertions)]
+pub fn loc<'a, P, Val>(parser: P) -> BoxedParser<'a, Located<Val>>
+where
+    P: Parser<'a, Val>,
+    P: 'a,
+    Val: 'a,
+{
+    BoxedParser::new(loc_impl(parser))
+}
+
+#[cfg(debug_assertions)]
+pub fn attempt<'a, P, Val>(attempting: Attempting, parser: P) -> BoxedParser<'a, Val>
+where
+    P: Parser<'a, Val>,
+    P: 'a,
+    Val: 'a,
+{
+    BoxedParser::new(attempt_impl(attempting, parser))
+}
+
+#[cfg(debug_assertions)]
+pub fn zero_or_more<'a, P, A>(parser: P) -> BoxedParser<'a, Vec<'a, A>>
+where
+    P: Parser<'a, A>,
+    P: 'a,
+{
+    BoxedParser::new(zero_or_more_impl(parser))
+}
+
+#[cfg(debug_assertions)]
+pub fn char<'a>(expected: char) -> BoxedParser<'a, ()> {
+    BoxedParser::new(char_impl(expected))
+}
+
+#[cfg(debug_assertions)]
+pub fn string<'a>(keyword: &'static str) -> BoxedParser<'a, ()> {
+    BoxedParser::new(string_impl(keyword))
+}
+
+#[cfg(debug_assertions)]
+pub fn either<'a, P1, P2, A, B>(p1: P1, p2: P2) -> BoxedParser<'a, Either<A, B>>
+where
+    P1: Parser<'a, A>,
+    P1: 'a,
+    P2: Parser<'a, B>,
+    P2: 'a,
+    A: 'a,
+    B: 'a,
+{
+    BoxedParser::new(either_impl(p1, p2))
+}
+
+#[cfg(debug_assertions)]
+pub fn one_or_more<'a, P, A>(parser: P) -> BoxedParser<'a, Vec<'a, A>>
+where
+    P: Parser<'a, A>,
+    P: 'a,
+{
+    BoxedParser::new(one_or_more_impl(parser))
+}