From 54ae2ff7c0f5602e25f38d921562015a141f7306 Mon Sep 17 00:00:00 2001 From: Dirkjan Ochtman Date: Tue, 24 Jul 2018 15:00:41 +0100 Subject: Move buffer maintenance utilities into a separate type --- askama_derive/src/generator.rs | 215 +++++++++++++++++++++++------------------ 1 file changed, 120 insertions(+), 95 deletions(-) (limited to 'askama_derive/src') diff --git a/askama_derive/src/generator.rs b/askama_derive/src/generator.rs index db9ac17..b805ec8 100644 --- a/askama_derive/src/generator.rs +++ b/askama_derive/src/generator.rs @@ -22,14 +22,10 @@ struct Generator<'a> { input: &'a TemplateInput<'a>, // All contexts, keyed by the package-relative template path contexts: &'a HashMap<&'a PathBuf, Context<'a>>, - // The buffer to generate the code into - buf: String, - // The current level of indentation (in spaces) - indent: u8, - // Whether the output buffer is currently at the start of a line - start: bool, // Variables accessible directly from the current scope (not redirected to context) locals: SetChain<'a, &'a str>, + // Top-level buffer for writing code into + buf: Buffer, // Suffix whitespace from the previous literal. Will be flushed to the // output buffer unless suppressed by whitespace suppression on the next // non-literal. @@ -56,10 +52,8 @@ impl<'a> Generator<'a> { Generator { input, contexts, - buf: String::new(), - indent, - start: true, locals, + buf: Buffer::new(indent), next_ws: None, skip_ws: false, vars: 0, @@ -70,7 +64,7 @@ impl<'a> Generator<'a> { fn child(&mut self) -> Generator { let locals = SetChain::with_parent(&self.locals); - Self::new(self.input, self.contexts, locals, self.indent) + Self::new(self.input, self.contexts, locals, self.buf.indent) } // Takes a Context and generates the relevant implementations. @@ -97,13 +91,13 @@ impl<'a> Generator<'a> { if cfg!(feature = "actix-web") { self.impl_actix_web_responder(); } - self.buf + self.buf.buf } // Implement `Template` for the given context struct. fn impl_template(&mut self, ctx: &'a Context, heritage: &Option>) { self.write_header("::askama::Template", None); - self.writeln( + self.buf.writeln( "fn render_into(&self, writer: &mut ::std::fmt::Write) -> \ ::askama::Result<()> {", ); @@ -115,14 +109,17 @@ impl<'a> Generator<'a> { } self.flush_ws(WS(false, false)); - self.writeln("Ok(())"); - self.writeln("}"); + self.buf.writeln("Ok(())"); + self.buf.writeln("}"); - self.writeln("fn extension(&self) -> Option<&str> {"); - self.writeln(&format!("{:?}", self.input.path.extension().map(|s| s.to_str().unwrap()))); - self.writeln("}"); + self.buf.writeln("fn extension(&self) -> Option<&str> {"); + self.buf.writeln(&format!( + "{:?}", + self.input.path.extension().map(|s| s.to_str().unwrap()) + )); + self.buf.writeln("}"); - self.writeln("}"); + self.buf.writeln("}"); } fn trait_blocks(&mut self, heritage: &Heritage<'a>) { @@ -140,8 +137,8 @@ impl<'a> Generator<'a> { format!("{}_g{}", name, gen) }; - self.writeln("#[allow(unused_variables)]"); - self.writeln(&format!( + self.buf.writeln("#[allow(unused_variables)]"); + self.buf.writeln(&format!( "fn render_block_{}_into(&self, writer: &mut ::std::fmt::Write) \ -> ::askama::Result<()> {{", fname @@ -156,8 +153,8 @@ impl<'a> Generator<'a> { self.locals.pop(); self.flush_ws(*ws2); - self.writeln("Ok(())"); - self.writeln("}"); + self.buf.writeln("Ok(())"); + self.buf.writeln("}"); } else { panic!("only block definitions allowed here"); } @@ -167,46 +164,50 @@ impl<'a> Generator<'a> { } } } - self.writeln("}"); + self.buf.writeln("}"); - self.writeln(&format!("pub trait {} {{", trait_name)); + self.buf.writeln(&format!("pub trait {} {{", trait_name)); for name in methods { - self.writeln(&format!( + self.buf.writeln(&format!( "fn render_block_{}_into(&self, writer: &mut ::std::fmt::Write) \ -> ::askama::Result<()>;", name )); } - self.writeln("}"); + self.buf.writeln("}"); } // Implement `Deref` for an inheriting context struct. fn deref_to_parent(&mut self, parent_type: &syn::Type) { self.write_header("::std::ops::Deref", None); - self.writeln(&format!( + self.buf.writeln(&format!( "type Target = {};", parent_type.into_token_stream() )); - self.writeln("fn deref(&self) -> &Self::Target {"); - self.writeln("&self._parent"); - self.writeln("}"); - self.writeln("}"); + self.buf.writeln("fn deref(&self) -> &Self::Target {"); + self.buf.writeln("&self._parent"); + self.buf.writeln("}"); + self.buf.writeln("}"); } // Implement `Display` for the given context struct. fn impl_display(&mut self) { self.write_header("::std::fmt::Display", None); - self.writeln("fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {"); - self.writeln("self.render_into(f).map_err(|_| ::std::fmt::Error {})"); - self.writeln("}"); - self.writeln("}"); + self.buf + .writeln("fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {"); + self.buf + .writeln("self.render_into(f).map_err(|_| ::std::fmt::Error {})"); + self.buf.writeln("}"); + self.buf.writeln("}"); } // Implement iron's Modifier if enabled fn impl_modifier_response(&mut self) { self.write_header("::askama::iron::Modifier<::askama::iron::Response>", None); - self.writeln("fn modify(self, res: &mut ::askama::iron::Response) {"); - self.writeln("res.body = Some(Box::new(self.render().unwrap().into_bytes()));"); + self.buf + .writeln("fn modify(self, res: &mut ::askama::iron::Response) {"); + self.buf + .writeln("res.body = Some(Box::new(self.render().unwrap().into_bytes()));"); let ext = self.input .path @@ -214,13 +215,14 @@ impl<'a> Generator<'a> { .map_or("", |s| s.to_str().unwrap_or("")); match ext { "html" | "htm" => { - self.writeln("::askama::iron::ContentType::html().0.modify(res);"); + self.buf + .writeln("::askama::iron::ContentType::html().0.modify(res);"); } _ => (), }; - self.writeln("}"); - self.writeln("}"); + self.buf.writeln("}"); + self.buf.writeln("}"); } // Implement Rocket's `Responder`. @@ -228,7 +230,7 @@ impl<'a> Generator<'a> { let lifetime = syn::Lifetime::new("'askama", Span::call_site()); let param = syn::GenericParam::Lifetime(syn::LifetimeDef::new(lifetime)); self.write_header("::askama::rocket::Responder<'askama>", Some(vec![param])); - self.writeln( + self.buf.writeln( "fn respond_to(self, _: &::askama::rocket::Request) \ -> ::askama::rocket::Result<'askama> {", ); @@ -237,18 +239,20 @@ impl<'a> Generator<'a> { Some(s) => s.to_str().unwrap(), None => "txt", }; - self.writeln(&format!("::askama::rocket::respond(&self, {:?})", ext)); + self.buf + .writeln(&format!("::askama::rocket::respond(&self, {:?})", ext)); - self.writeln("}"); - self.writeln("}"); + self.buf.writeln("}"); + self.buf.writeln("}"); } // Implement Actix-web's `Responder`. fn impl_actix_web_responder(&mut self) { self.write_header("::askama::actix_web::Responder", None); - self.writeln("type Item = ::askama::actix_web::HttpResponse;"); - self.writeln("type Error = ::askama::actix_web::Error;"); - self.writeln( + self.buf + .writeln("type Item = ::askama::actix_web::HttpResponse;"); + self.buf.writeln("type Error = ::askama::actix_web::Error;"); + self.buf.writeln( "fn respond_to(self, _req: &::askama::actix_web::HttpRequest) \ -> Result {", ); @@ -257,10 +261,11 @@ impl<'a> Generator<'a> { Some(s) => s.to_str().unwrap(), None => "txt", }; - self.writeln(&format!("::askama::actix_web::respond(&self, {:?})", ext)); + self.buf + .writeln(&format!("::askama::actix_web::respond(&self, {:?})", ext)); - self.writeln("}"); - self.writeln("}"); + self.buf.writeln("}"); + self.buf.writeln("}"); } // Writes header for the `impl` for `TraitFromPathName` or `Template` @@ -274,7 +279,7 @@ impl<'a> Generator<'a> { } let (_, orig_ty_generics, _) = self.input.ast.generics.split_for_impl(); let (impl_generics, _, where_clause) = generics.split_for_impl(); - self.writeln( + self.buf.writeln( format!( "{} {} for {}{} {{", quote!(impl#impl_generics), @@ -361,25 +366,25 @@ impl<'a> Generator<'a> { Some(ref expr) => { let expr_code = self.visit_expr_root(expr); if i == 0 { - self.write("if "); + self.buf.write("if "); } else { - self.dedent(); - self.write("} else if "); + self.buf.dedent(); + self.buf.write("} else if "); } - self.write(&expr_code); + self.buf.write(&expr_code); } None => { - self.dedent(); - self.write("} else"); + self.buf.dedent(); + self.buf.write("} else"); } } - self.writeln(" {"); + self.buf.writeln(" {"); self.locals.push(); self.handle(ctx, nodes, AstLevel::Nested); self.locals.pop(); } self.handle_ws(ws); - self.writeln("}"); + self.buf.writeln("}"); } fn write_match( @@ -399,7 +404,7 @@ impl<'a> Generator<'a> { } let expr_code = self.visit_expr_root(expr); - self.writeln(&format!("match &{} {{", expr_code)); + self.buf.writeln(&format!("match &{} {{", expr_code)); for arm in arms { let &(ws, ref variant, ref params, ref body) = arm; self.locals.push(); @@ -407,29 +412,29 @@ impl<'a> Generator<'a> { Some(ref param) => { self.visit_match_variant(param); } - None => self.write("_"), + None => self.buf.write("_"), }; if !params.is_empty() { - self.write("("); + self.buf.write("("); for (i, param) in params.iter().enumerate() { if let MatchParameter::Name(p) = *param { self.locals.insert(p); } if i > 0 { - self.write(", "); + self.buf.write(", "); } self.visit_match_param(param); } - self.write(")"); + self.buf.write(")"); } - self.writeln(" => {"); + self.buf.writeln(" => {"); self.handle_ws(ws); self.handle(ctx, body, AstLevel::Nested); - self.writeln("}"); + self.buf.writeln("}"); self.locals.pop(); } - self.writeln("}"); + self.buf.writeln("}"); self.handle_ws(ws2); } @@ -446,17 +451,18 @@ impl<'a> Generator<'a> { self.locals.push(); let expr_code = self.visit_expr_root(iter); - self.write("for (_loop_index, "); + self.buf.write("for (_loop_index, "); let targets = self.visit_target(var); for name in &targets { self.locals.insert(name); - self.write(name); + self.buf.write(name); } - self.writeln(&format!(") in (&{}).into_iter().enumerate() {{", expr_code)); + self.buf + .writeln(&format!(") in (&{}).into_iter().enumerate() {{", expr_code)); self.handle(ctx, body, AstLevel::Nested); self.handle_ws(ws2); - self.writeln("}"); + self.buf.writeln("}"); self.locals.pop(); } @@ -474,7 +480,7 @@ impl<'a> Generator<'a> { Some(ref name) => format!("self.render_block_{}_into(writer)?;", name), None => panic!("cannot call 'super()' outside block"), }; - self.writeln(&line); + self.buf.writeln(&line); self.prepare_ws(ws); self.used_super = true; return; @@ -498,7 +504,7 @@ impl<'a> Generator<'a> { self.flush_ws(ws); // Cannot handle_ws() here: whitespace from macro definition comes first self.locals.push(); - self.writeln("{"); + self.buf.writeln("{"); self.prepare_ws(def.ws1); for (i, arg) in def.args.iter().enumerate() { @@ -506,13 +512,13 @@ impl<'a> Generator<'a> { args.get(i) .unwrap_or_else(|| panic!("macro '{}' takes more than {} arguments", name, i)), ); - self.write(&format!("let {} = &{};", arg, expr_code)); + self.buf.write(&format!("let {} = &{};", arg, expr_code)); self.locals.insert(arg); } self.handle(ctx, &def.nodes, AstLevel::Nested); self.flush_ws(def.ws2); - self.writeln("}"); + self.buf.writeln("}"); self.locals.pop(); self.prepare_ws(ws); } @@ -527,22 +533,22 @@ impl<'a> Generator<'a> { let nested = { let mut gen = self.child(); gen.handle(ctx, &nodes, AstLevel::Nested); - gen.buf + gen.buf.buf }; - self.buf.push_str(&nested); + self.buf.write(&nested); self.prepare_ws(ws); } fn write_let_decl(&mut self, ws: WS, var: &'a Target) { self.handle_ws(ws); - self.write("let "); + self.buf.write("let "); match *var { Target::Name(name) => { self.locals.insert(name); - self.write(name); + self.buf.write(name); } } - self.writeln(";"); + self.buf.writeln(";"); } fn write_let(&mut self, ws: WS, var: &'a Target, val: &Expr) { @@ -553,18 +559,19 @@ impl<'a> Generator<'a> { match *var { Target::Name(name) => { if !self.locals.contains(name) { - self.write("let "); + self.buf.write("let "); self.locals.insert(name); } - self.write(name); + self.buf.write(name); } } - self.write(&format!(" = {};", &code)); + self.buf.write(&format!(" = {};", &code)); } fn write_block(&mut self, ws1: WS, name: &str, ws2: WS) { self.flush_ws(ws1); - self.writeln(&format!("self.render_block_{}_into(writer)?;", name)); + self.buf + .writeln(&format!("self.render_block_{}_into(writer)?;", name)); self.prepare_ws(ws2); } @@ -572,16 +579,16 @@ impl<'a> Generator<'a> { self.handle_ws(ws); let mut code = String::new(); let wrapped = self.visit_expr(s, &mut code); - self.writeln(&format!("let askama_expr = &{};", code)); + self.buf.writeln(&format!("let askama_expr = &{};", code)); use self::DisplayWrap::*; use super::input::EscapeMode::*; - self.write("writer.write_fmt(format_args!(\"{}\", "); - self.write(match (wrapped, &self.input.escaping) { + self.buf.write("writer.write_fmt(format_args!(\"{}\", "); + self.buf.write(match (wrapped, &self.input.escaping) { (Wrapped, &Html) | (Wrapped, &None) | (Unwrapped, &None) => "askama_expr", (Unwrapped, &Html) => "&::askama::MarkupDisplay::from(askama_expr)", }); - self.writeln("))?;"); + self.buf.writeln("))?;"); } fn write_lit(&mut self, lws: &'a str, val: &str, rws: &'a str) { @@ -593,11 +600,11 @@ impl<'a> Generator<'a> { assert!(rws.is_empty()); self.next_ws = Some(lws); } else { - self.writeln(&format!("writer.write_str({:#?})?;", lws)); + self.buf.writeln(&format!("writer.write_str({:#?})?;", lws)); } } if !val.is_empty() { - self.writeln(&format!("writer.write_str({:#?})?;", val)); + self.buf.writeln(&format!("writer.write_str({:#?})?;", val)); } if !rws.is_empty() { self.next_ws = Some(rws); @@ -653,7 +660,7 @@ impl<'a> Generator<'a> { DisplayWrap::Unwrapped } }; - self.write(&code); + self.buf.write(&code); wrapped } @@ -667,7 +674,7 @@ impl<'a> Generator<'a> { DisplayWrap::Unwrapped } }; - self.write(&code); + self.buf.write(&code); wrapped } @@ -732,7 +739,8 @@ impl<'a> Generator<'a> { self.visit_expr(arg, code); let idx = self.vars; self.vars += 1; - self.writeln(&format!("let var{} = {};", idx, &code[offset..])); + self.buf + .writeln(&format!("let var{} = {};", idx, &code[offset..])); code.truncate(offset); code.push_str(&format!("var{}", idx)); } else { @@ -901,7 +909,7 @@ impl<'a> Generator<'a> { if self.next_ws.is_some() && !ws.0 { let val = self.next_ws.unwrap(); if !val.is_empty() { - self.writeln(&format!("writer.write_str({:#?})?;", val)); + self.buf.writeln(&format!("writer.write_str({:#?})?;", val)); } } self.next_ws = None; @@ -913,8 +921,25 @@ impl<'a> Generator<'a> { fn prepare_ws(&mut self, ws: WS) { self.skip_ws = ws.1; } +} - /* Helper methods for writing to internal buffer */ +struct Buffer { + // The buffer to generate the code into + buf: String, + // The current level of indentation (in spaces) + indent: u8, + // Whether the output buffer is currently at the start of a line + start: bool, +} + +impl Buffer { + fn new(indent: u8) -> Self { + Self { + buf: String::new(), + indent, + start: true, + } + } fn writeln(&mut self, s: &str) { if s.is_empty() { -- cgit