Pull out static generated file heading into one string literal

generate/src/write.rs

@@ -1,30 +1,25 @@
 use crate::output::Output;
 use crate::{is_xid_continue, is_xid_start, CHUNK};
 
-pub fn output(index_start: &[u8], index_continue: &[u8], halfdense: &[u8]) -> Output {
-    let mut out = Output::new();
-    writeln!(
-        out,
-        "// \x40generated by ../generate. To regenerate, run the following in the repo root:",
-    );
-    writeln!(out, "//");
-    writeln!(
-        out,
-        "// $ curl -LO https://www.unicode.org/Public/zipped/14.0.0/UCD.zip",
-    );
-    writeln!(out, "// $ unzip UCD.zip -d UCD");
-    writeln!(out, "// $ cargo run --manifest-path generate/Cargo.toml");
-    writeln!(out);
+const HEAD: &str = "\
+// \x40generated by ../generate. To regenerate, run the following in the repo root:
+//
+// $ curl -LO https://www.unicode.org/Public/zipped/14.0.0/UCD.zip
+// $ unzip UCD.zip -d UCD
+// $ cargo run --manifest-path generate/Cargo.toml
 
-    writeln!(out, "const T: bool = true;");
-    writeln!(out, "const F: bool = false;");
-    writeln!(out);
+const T: bool = true;
+const F: bool = false;
 
-    writeln!(out, "#[repr(C, align(8))]");
-    writeln!(out, "pub(crate) struct Align8<T>(pub(crate) T);");
-    writeln!(out, "#[repr(C, align(64))]");
-    writeln!(out, "pub(crate) struct Align64<T>(pub(crate) T);");
-    writeln!(out);
+#[repr(C, align(8))]
+pub(crate) struct Align8<T>(pub(crate) T);
+#[repr(C, align(64))]
+pub(crate) struct Align64<T>(pub(crate) T);
+";
+
+pub fn output(index_start: &[u8], index_continue: &[u8], halfdense: &[u8]) -> Output {
+    let mut out = Output::new();
+    writeln!(out, "{}", HEAD);
 
     writeln!(
         out,