1 files changed, 127 insertions, 0 deletions
diff --git a/mingling_macros/src/func/r_print.rs b/mingling_macros/src/func/r_print.rs
new file mode 100644
index 0000000..86ea52f
--- /dev/null
+++ b/mingling_macros/src/func/r_print.rs
@@ -0,0 +1,127 @@
+use proc_macro::TokenStream;
+use proc_macro2::TokenStream as TokenStream2;
+use quote::quote;
+use syn::parse::{Parse, ParseStream};
+use syn::{Ident, Token};
+
+/// Parsed input for `r_println!` and `r_print!`.
+///
+/// Two forms:
+/// - `(ident, format_args...)`       — explicit buffer
+/// - `(format_args...)`              — implicit `__render_result_buffer`
+enum PrintInput {
+    Explicit { dst: Ident, args: TokenStream2 },
+    Implicit { args: TokenStream2 },
+}
+
+impl Parse for PrintInput {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        // Peek: if the next token is an ident followed by a comma, it's the explicit form
+        if input.peek(Ident) && input.peek2(Token![,]) {
+            let dst: Ident = input.parse()?;
+            let _comma: Token![,] = input.parse()?;
+            let args: TokenStream2 = input.parse()?;
+            Ok(PrintInput::Explicit { dst, args })
+        } else {
+            let args: TokenStream2 = input.parse()?;
+            Ok(PrintInput::Implicit { args })
+        }
+    }
+}
+
+fn expand_print(input: TokenStream, method: &str) -> TokenStream {
+    let parsed: PrintInput = match syn::parse(input) {
+        Ok(p) => p,
+        Err(e) => return e.to_compile_error().into(),
+    };
+
+    let method_ident = Ident::new(method, proc_macro2::Span::call_site());
+
+    let expanded = match parsed {
+        PrintInput::Explicit { dst, args } => {
+            quote! {
+                #dst.#method_ident(format!(#args))
+            }
+        }
+        PrintInput::Implicit { args } => {
+            quote! {
+                __render_result_buffer.#method_ident(format!(#args))
+            }
+        }
+    };
+
+    expanded.into()
+}
+
+pub(crate) fn r_println(input: TokenStream) -> TokenStream {
+    expand_print(input, "println")
+}
+
+pub(crate) fn r_print(input: TokenStream) -> TokenStream {
+    expand_print(input, "print")
+}
+
+pub(crate) fn r_eprintln(input: TokenStream) -> TokenStream {
+    expand_print(input, "eprintln")
+}
+
+pub(crate) fn r_eprint(input: TokenStream) -> TokenStream {
+    expand_print(input, "eprint")
+}
+
+/// Parsed input for `r_append!`.
+///
+/// Two forms:
+/// - `(dst, src)`       — explicit buffer and source
+/// - `(src)`            — implicit `__render_result_buffer`
+struct AppendInput {
+    dst: Option<Ident>,
+    src: proc_macro2::TokenStream,
+}
+
+impl Parse for AppendInput {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        if input.peek(Ident) && input.peek2(Token![,]) {
+            let dst: Ident = input.parse()?;
+            let _comma: Token![,] = input.parse()?;
+            let src: TokenStream2 = input.parse()?;
+            Ok(AppendInput {
+                dst: Some(dst),
+                src,
+            })
+        } else {
+            let src: TokenStream2 = input.parse()?;
+            Ok(AppendInput { dst: None, src })
+        }
+    }
+}
+
+/// `r_append!` macro: appends the contents of another `RenderResult` to this one.
+///
+/// Two forms:
+/// - `r_append!(dst, src)` — appends `src` into `dst`
+/// - `r_append!(src)`      — appends `src` into `__render_result_buffer`
+pub(crate) fn r_append(input: TokenStream) -> TokenStream {
+    let parsed: AppendInput = match syn::parse(input) {
+        Ok(p) => p,
+        Err(e) => return e.to_compile_error().into(),
+    };
+
+    let dst_ident = parsed.dst.clone();
+    let src_tokens = parsed.src;
+
+    let expanded = match dst_ident {
+        Some(dst) => {
+            quote! {
+                #dst.append_other(#src_tokens);
+            }
+        }
+        None => {
+            quote! {
+                __render_result_buffer.append_other(#src_tokens);
+            }
+        }
+    };
+
+    expanded.into()
+}