feat(core)!: replace RenderResult with buffered output model

Remove `Deref<Target=str>` and `render_text:String` in favor of
`render_buffer:Vec<(String, RenderResultMode)>` and an
`immediate_output`
flag. Add `RenderResultMode` enum, `r_eprint!`/`r_eprintln!` macros, and
new buffer manipulation methods (`append_to_buffer`, `eprint`, etc.).
Update `Display` to trim output and remove trailing newline. Migrate all
callers and tests away from `Deref` usage.

1 files changed, 12 insertions, 0 deletions

diff --git a/mingling/src/lib.rs b/mingling/src/lib.rs
index f5362d5..3539647 100644
--- a/mingling/src/lib.rs
+++ b/mingling/src/lib.rs
@@ -98,6 +98,12 @@ pub mod macros {
     /// `#[program_setup]` - Used to generate program setup
     #[cfg(feature = "extra_macros")]
     pub use mingling_macros::program_setup;
+    /// `r_eprint!` - Prints text to a `RenderResult` error buffer (without newline).
+    /// See the macro documentation for implicit vs. explicit buffer usage.
+    pub use mingling_macros::r_eprint;
+    /// `r_eprintln!` - Prints text to a `RenderResult` error buffer (with newline).
+    /// See the macro documentation for implicit vs. explicit buffer usage.
+    pub use mingling_macros::r_eprintln;
     /// `r_print!` - Prints text to a `RenderResult` buffer (without newline).
     /// See the macro documentation for implicit vs. explicit buffer usage.
     pub use mingling_macros::r_print;
@@ -229,6 +235,12 @@ pub mod prelude {
     /// Like `pack!` but also marks the type for structured output
     #[cfg(all(feature = "macros", feature = "structural_renderer"))]
     pub use mingling_macros::pack_structural;
+    /// `r_eprint!` - Prints text to a `RenderResult` error buffer (without newline).
+    /// See the macro documentation for implicit vs. explicit buffer usage.
+    pub use mingling_macros::r_eprint;
+    /// `r_eprintln!` - Prints text to a `RenderResult` error buffer (with newline).
+    /// See the macro documentation for implicit vs. explicit buffer usage.
+    pub use mingling_macros::r_eprintln;
     /// `r_print!` - Prints text to a `RenderResult` buffer (without newline).
     /// See the macro documentation for implicit vs. explicit buffer usage.
     pub use mingling_macros::r_print;