Rewrite TextConsumer

src/common.rs

@@ -4,3 +4,6 @@ mod common_macros;
 pub mod consumer;
 pub mod errors;
 pub mod producer;
+
+#[cfg(all(feature = "dev", feature = "alloc"))]
+pub(crate) mod test_yielder;

src/common/consumer.rs

@@ -28,7 +28,7 @@ mod scramble;
 #[cfg(feature = "dev")]
 pub use scramble::{ConsumeOperations, Scramble_ as Scramble};
 
-#[cfg(feature = "dev")]
+#[cfg(all(feature = "dev", feature = "alloc"))]
 mod test_consumer;
-#[cfg(feature = "dev")]
+#[cfg(all(feature = "dev", feature = "alloc"))]
 pub use test_consumer::TestConsumer_ as TestConsumer;

src/common/consumer/into_vec.rs

@@ -31,16 +31,28 @@ impl<T> Default for IntoVec_<T> {
 }
 
 impl<T> IntoVec_<T> {
+    /// Create a new consumer that collects data into a Vec.
     pub fn new() -> IntoVec_<T> {
         let invariant = Invariant::new(IntoVec(Vec::new()));
 
         IntoVec_(invariant)
     }
 
+    /// Convert `self` into the vector of all consumed items.
     pub fn into_vec(self) -> Vec<T> {
         let inner = self.0.into_inner();
         inner.into_inner()
     }
+
+    /// Return the remaining capacity of the vector, i.e., how many more items it can consume without reallocating.
+    pub fn remaining_capacity(&self) -> usize {
+        self.0.as_ref().remaining_capacity()
+    }
+
+    /// Allocate capacity for at least `additional` more items. See [`std::vec::Vec::reserve`].
+    pub fn reserve(&mut self, additional: usize) {
+        self.0.as_mut().reserve(additional)
+    }
 }
 
 impl<T, A: Allocator> IntoVec_<T, A> {
@@ -62,6 +74,16 @@ invarianted_impl_bulk_consumer_sync_and_local_nb!(IntoVec_<T: Copy, A: Allocator
 #[derive(Debug)]
 struct IntoVec<T, A: Allocator = Global>(Vec<T, A>);
 
+impl<T, A: Allocator> IntoVec<T, A> {
+    fn remaining_capacity(&self) -> usize {
+        self.0.capacity() - self.0.len()
+    }
+
+    fn reserve(&mut self, additional: usize) {
+        self.0.reserve(additional)
+    }
+}
+
 impl<T, A: Allocator> AsRef<Vec<T, A>> for IntoVec<T, A> {
     fn as_ref(&self) -> &Vec<T, A> {
         &self.0