Implement include! macro

sailfish-compiler/src/compiler.rs

@@ -1,13 +1,14 @@
 use quote::ToTokens;
 use std::fs;
 use std::path::Path;
+use std::sync::Arc;
 
 use crate::config::Config;
 use crate::error::*;
 use crate::optimizer::Optimizer;
 use crate::parser::Parser;
 use crate::resolver::Resolver;
-use crate::translator::Translator;
+use crate::translator::{Translator, TranslatedSource};
 use crate::util::rustfmt_block;
 
 #[derive(Default)]
@@ -24,21 +25,35 @@ impl Compiler {
         Self { config }
     }
 
-    pub fn compile_file(&self, input: &Path, output: &Path) -> Result<(), Error> {
-        // TODO: introduce cache system
-
+    fn translate_file_contents(&self, input: &Path) -> Result<TranslatedSource, Error> {
         let parser = Parser::new().delimiter(self.config.delimiter);
         let translator = Translator::new().escape(self.config.escape);
-        let resolver = Resolver::new();
+        let content = fs::read_to_string(input)
+            .chain_err(|| format!("Failed to open template file: {:?}", input))?;
+
+        let stream = parser.parse(&*content);
+        translator.translate(stream)
+    }
+
+    pub fn compile_file(&self, template_dir: &Path, input: &Path, output: &Path) -> Result<(), Error> {
+        // TODO: introduce cache system
+
+        let input = if input.is_absolute() {
+            input.to_owned()
+        } else {
+            template_dir.join(input)
+        };
+        
+        let include_handler = Arc::new(|arg: &str| -> Result<_, Error> {
+            let input_file = template_dir.join(arg);
+            Ok(self.translate_file_contents(&*input_file)?.ast)
+        });
+
+        let resolver = Resolver::new().include_handler(include_handler);
         let optimizer = Optimizer::new();
 
         let compile_file = |input: &Path, output: &Path| -> Result<(), Error> {
-            let content = fs::read_to_string(&*input)
-                .chain_err(|| format!("Failed to open template file: {:?}", input))?;
-
-            let stream = parser.parse(&*content);
-            let mut tsource = translator.translate(stream)?;
-            drop(content);
+            let mut tsource = self.translate_file_contents(input)?;
 
             resolver.resolve(&mut tsource.ast)?;
             optimizer.optimize(&mut tsource.ast);

sailfish-compiler/src/procmacro.rs

@@ -113,6 +113,7 @@ struct TemplateStruct {
 }
 
 fn compile(
+    template_dir: &Path,
     input_file: &Path,
     output_file: &Path,
     options: &DeriveTemplateOptions,
@@ -126,7 +127,7 @@ fn compile(
     }
 
     let compiler = Compiler::with_config(config);
-    compiler.compile_file(input_file, &*output_file)
+    compiler.compile_file(template_dir, input_file, &*output_file)
 }
 
 fn derive_template_impl(tokens: TokenStream) -> Result<TokenStream, syn::Error> {
@@ -138,15 +139,13 @@ fn derive_template_impl(tokens: TokenStream) -> Result<TokenStream, syn::Error>
         all_options.merge(opt)?;
     }
 
+    let mut template_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").expect(
+        "Internal error: environmental variable `CARGO_MANIFEST_DIR` is not set.",
+    ));
+    template_dir.push("templates");
+
     let input_file = match all_options.path {
-        Some(ref path) => {
-            let mut input = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").expect(
-                "Internal error: environmental variable `CARGO_MANIFEST_DIR` is not set.",
-            ));
-            input.push("templates");
-            input.push(path.value());
-            input
-        }
+        Some(ref path) => template_dir.join(path.value()),
         None => {
             return Err(syn::Error::new(
                 Span::call_site(),
@@ -178,7 +177,7 @@ fn derive_template_impl(tokens: TokenStream) -> Result<TokenStream, syn::Error>
     output_file.push("templates");
     output_file.push(filename);
 
-    compile(&*input_file, &*output_file, &all_options)
+    compile(&*template_dir, &*input_file, &*output_file, &all_options)
         .map_err(|e| syn::Error::new(Span::call_site(), e))?;
 
     let input_file_string = input_file.to_string_lossy();

sailfish-compiler/src/resolver.rs

@@ -1,19 +1,127 @@
-use syn::Block;
+use std::sync::Arc;
+use syn::visit_mut::VisitMut;
+use syn::{Block, Expr, ExprBlock, LitStr};
 
 use crate::error::*;
 
-#[derive(Clone, Debug, Default)]
-pub struct Resolver {}
+macro_rules! matches_or_else {
+    ($val:expr, $p:pat, $ok:expr, $else:expr) => {
+        match $val {
+            $p => $ok,
+            _ => $else,
+        }
+    };
+}
 
-impl Resolver {
-    #[inline]
+macro_rules! return_if_some {
+    ($val:expr) => {
+        if $val.is_some() {
+            return;
+        }
+    };
+}
+
+fn empty_block() -> Block {
+    Block {
+        brace_token: Default::default(),
+        stmts: Vec::new(),
+    }
+}
+
+struct ResolverImpl<'h> {
+    deps: Vec<String>,
+    error: Option<Error>,
+    include_handler: Arc<dyn 'h + Fn(&str) -> Result<Block, Error>>,
+}
+
+impl<'h> VisitMut for ResolverImpl<'h> {
+    fn visit_expr_mut(&mut self, i: &mut Expr) {
+        return_if_some!(self.error);
+        let em = matches_or_else!(*i, Expr::Macro(ref em), em, {
+            syn::visit_mut::visit_expr_mut(self, i);
+            return;
+        });
+
+        // check if path is `include`
+        if !em.mac.path.is_ident("include") {
+            syn::visit_mut::visit_expr_mut(self, i);
+            return;
+        }
+
+        let arg = match syn::parse2::<LitStr>(em.mac.tokens.clone()) {
+            Ok(l) => l.value(),
+            Err(e) => {
+                let mut e = Error::from(e);
+                e.chains.push(ErrorKind::AnalyzeError(
+                    "invalid arguments for `include` macro".to_owned(),
+                ));
+                self.error = Some(e);
+                return;
+            }
+        };
+
+        // TODO: support relative path
+        if arg.starts_with("./") || arg.starts_with("../") {
+            self.error = Some(make_error!(ErrorKind::Unimplemented(
+                "include! with relative path is not supported yet.".to_owned()
+            )))
+        }
+
+        // parse and translate the child template
+        let mut blk = match (*self.include_handler)(&arg) {
+            Ok(blk) => blk,
+            Err(mut e) => {
+                e.chains
+                    .push(ErrorKind::Other(format!("Failed to include {}", arg)));
+                self.error = Some(e);
+                return;
+            }
+        };
+
+        self.deps.push(arg);
+        syn::visit_mut::visit_block_mut(self, &mut blk);
+
+        *i = Expr::Block(ExprBlock {
+            attrs: Vec::new(),
+            label: None,
+            block: blk,
+        });
+    }
+}
+
+#[derive(Clone)]
+pub struct Resolver<'h> {
+    include_handler: Arc<dyn 'h + Fn(&str) -> Result<Block, Error>>,
+}
+
+impl<'h> Resolver<'h> {
     pub fn new() -> Self {
-        Self {}
+        Self {
+            include_handler: Arc::new(|_| {
+                Err(make_error!(ErrorKind::AnalyzeError(
+                    "You cannot use `include` macro inside templates".to_owned()
+                )))
+            }),
+        }
     }
 
     #[inline]
-    pub fn resolve(&self, _ast: &mut Block) -> Result<(), Error> {
-        // not implemented yet
+    pub fn include_handler(
+        self,
+        new: Arc<dyn 'h + Fn(&str) -> Result<Block, Error>>,
+    ) -> Resolver<'h> {
+        Self {
+            include_handler: new,
+        }
+    }
+
+    #[inline]
+    pub fn resolve(&self, ast: &mut Block) -> Result<(), Error> {
+        ResolverImpl {
+            deps: Vec::new(),
+            error: None,
+            include_handler: Arc::clone(&self.include_handler)
+        }.visit_block_mut(ast);
         Ok(())
     }
 }