From 37af52f724ea03a12bdc6127f027333588af308e Mon Sep 17 00:00:00 2001
From: Marijn Suijten <marijns95@gmail.com>
Date: Wed, 18 Nov 2020 23:07:59 +0100
Subject: [PATCH] codegen/enums: Simplify custom to_string with quote!

This generates _identical_ code while being much more readable.
---
 src/codegen/enums.rs | 63 ++++++++++++++++++++------------------------
 1 file changed, 29 insertions(+), 34 deletions(-)

diff --git a/src/codegen/enums.rs b/src/codegen/enums.rs
index 9e08033fd..36f65af3f 100644
--- a/src/codegen/enums.rs
+++ b/src/codegen/enums.rs
@@ -81,47 +81,42 @@ fn generate_static_to_str(
     enum_: &Enumeration,
     function: &crate::analysis::functions::Info,
 ) -> Result<()> {
-    writeln!(w)?;
-    version_condition(w, env, function.version, false, 1)?;
-
-    // TODO: use the normal to_string name, and pass _by ref_!
-    // The trait_impls Display impl calls this... But it'll recursively
-    // call ToString::to_string -> Display::fmt if this function were by reference.
-    writeln!(w, "\tfn to_string(&self) -> &'static str {{")?;
+    let condition = version_condition_tokens(env, function.version, false);
 
     let unk_match = if enum_.members.iter().any(|m| m.name == "unknown") {
-        "Self::Unknown | "
+        quote!(Self::Unknown |)
     } else {
-        ""
+        quote!()
     };
 
-    writeln!(
-        w,
-        "\
-\t\tmatch self {{
-\t\t\t{}Self::__Unknown(_) => return \"UNKNOWN\",
-\t\t\t_ => {{}},
-\t\t}}",
-        unk_match
-    )?;
-
-    // TODO: Can we somehow reuse function_body_chunk::Builder here?
+    let native_call = {
+        // TODO: This can possibly be a function on Info
+        let crate_ = format_ident!("{}", env.main_sys_crate_name());
+        let name = format_ident!("{}", function.glib_name);
+        quote!(#crate_::#name(self.to_glib()))
+    };
 
-    writeln!(
-        w,
-        "\
-\t\tunsafe {{
-\t\t\tlet ptr = {}::{}(self.to_glib());
-\t\t\tif ptr.is_null() {{
-\t\t\t\treturn \"INVALID\";
-\t\t\t}}
-\t\t\tCStr::from_ptr(ptr).to_str().unwrap()
-\t\t}}
-\t}}",
-        env.main_sys_crate_name(),
-        function.glib_name
-    )?;
+    // TODO: use the normal to_string name, and pass _by ref_!
+    // The trait_impls Display impl calls this... But it'll recursively
+    // call ToString::to_string -> Display::fmt if this function were by reference.
+    let result = quote! {
+        #condition
+        fn to_string(&self) -> &'static str {
+            match self {
+                #unk_match Self::__Unknown(_) => return "UNKNOWN",
+                _ => {}
+            }
+            unsafe {
+                let ptr = #native_call;
+                if ptr.is_null() {
+                    return "INVALID";
+                }
+                CStr::from_ptr(ptr).to_str().unwrap()
+            }
+        }
+    };
 
+    writeln!(w, "{}", result)?;
     Ok(())
 }