Add the source code

bf-macro/src/lib.rs

@@ -0,0 +1,39 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, LitStr};
+
+/// Usage: brainfuck!("++>-[].,")
+#[proc_macro]
+pub fn brainfuck(input: TokenStream) -> TokenStream {
+    let lit = parse_macro_input!(input as LitStr);
+    let s = lit.value();
+
+    // Map characters -> OpCode tokens
+    let mut ops = Vec::new();
+    for ch in s.chars() {
+        let token = match ch {
+            '>' => Some(quote! { OpCode::IncrementPointer }),
+            '<' => Some(quote! { OpCode::DecrementPointer }),
+            '+' => Some(quote! { OpCode::Increment }),
+            '-' => Some(quote! { OpCode::Decrement }),
+            '.' => Some(quote! { OpCode::Write }),
+            ',' => Some(quote! { OpCode::Read }),
+            '[' => Some(quote! { OpCode::LoopBegin }),
+            ']' => Some(quote! { OpCode::LoopEnd }),
+            _ => None, // ignore comments/whitespace
+        };
+        if let Some(t) = token {
+            ops.push(t);
+        }
+    }
+
+    let n = ops.len();
+    // Expand to a const array; the caller gets a [OpCode; N]
+    let expanded = quote! {
+        {
+            const __BF_OPS: [OpCode; #n] = [ #(#ops),* ];
+            __BF_OPS
+        }
+    };
+    expanded.into()
+}