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extern crate askama_shared as shared;
#[macro_use]
extern crate nom;
extern crate proc_macro;
extern crate proc_macro2;
#[macro_use]
extern crate quote;
extern crate syn;
mod generator;
mod input;
mod parser;
use input::{Print, Source, TemplateInput};
use parser::{Expr, Macro, Node};
use proc_macro::TokenStream;
use shared::{read_config_file, Config};
use parser::parse;
use std::collections::HashMap;
use std::fs;
use std::path::{Path, PathBuf};
#[proc_macro_derive(Template, attributes(template))]
pub fn derive_template(input: TokenStream) -> TokenStream {
let ast: syn::DeriveInput = syn::parse(input).unwrap();
build_template(&ast).parse().unwrap()
}
/// Takes a `syn::DeriveInput` and generates source code for it
///
/// Reads the metadata from the `template()` attribute to get the template
/// metadata, then fetches the source from the filesystem. The source is
/// parsed, and the parse tree is fed to the code generator. Will print
/// the parse tree and/or generated source according to the `print` key's
/// value as passed to the `template()` attribute.
fn build_template(ast: &syn::DeriveInput) -> String {
let config_toml = read_config_file();
let config = Config::new(&config_toml);
let input = TemplateInput::new(ast, &config);
let source: String = match input.source {
Source::Source(ref s) => s.clone(),
Source::Path(_) => get_template_source(&input.path),
};
let mut sources = HashMap::new();
find_used_templates(&input, &mut sources, source);
let mut parsed = HashMap::new();
for (path, src) in &sources {
parsed.insert(path, parse(src, input.syntax));
}
let mut contexts = HashMap::new();
for (path, nodes) in &parsed {
contexts.insert(*path, Context::new(&input.config, path, nodes));
}
let ctx = &contexts[&input.path];
let heritage = if !ctx.blocks.is_empty() {
Some(Heritage::new(ctx, &contexts))
} else {
None
};
if input.print == Print::Ast || input.print == Print::All {
eprintln!("{:?}", parsed[&input.path]);
}
let code = generator::generate(&input, &contexts, &heritage);
if input.print == Print::Code || input.print == Print::All {
eprintln!("{}", code);
}
code
}
fn find_used_templates(input: &TemplateInput, map: &mut HashMap<PathBuf, String>, source: String) {
let mut check = vec![(input.path.clone(), source)];
while let Some((path, source)) = check.pop() {
for n in parse(&source, input.syntax) {
match n {
Node::Extends(Expr::StrLit(extends)) => {
let extends = input.config.find_template(extends, Some(&path));
let source = get_template_source(&extends);
check.push((extends, source));
}
Node::Import(_, import, _) => {
let import = input.config.find_template(import, Some(&path));
let source = get_template_source(&import);
check.push((import, source));
}
_ => {}
}
}
map.insert(path, source);
}
}
pub(crate) struct Heritage<'a> {
root: &'a Context<'a>,
blocks: BlockAncestry<'a>,
}
impl<'a> Heritage<'a> {
fn new<'n>(
mut ctx: &'n Context<'n>,
contexts: &'n HashMap<&'n PathBuf, Context<'n>>,
) -> Heritage<'n> {
let mut blocks: BlockAncestry<'n> = ctx
.blocks
.iter()
.map(|(name, def)| (*name, vec![(ctx, *def)]))
.collect();
while let Some(ref path) = ctx.extends {
ctx = &contexts[&path];
for (name, def) in &ctx.blocks {
blocks
.entry(name)
.or_insert_with(|| vec![])
.push((ctx, def));
}
}
Heritage { root: ctx, blocks }
}
}
type BlockAncestry<'a> = HashMap<&'a str, Vec<(&'a Context<'a>, &'a Node<'a>)>>;
pub(crate) struct Context<'a> {
nodes: &'a [Node<'a>],
extends: Option<PathBuf>,
blocks: HashMap<&'a str, &'a Node<'a>>,
macros: HashMap<&'a str, &'a Macro<'a>>,
imports: HashMap<&'a str, PathBuf>,
}
impl<'a> Context<'a> {
fn new<'n>(config: &Config, path: &Path, nodes: &'n [Node<'n>]) -> Context<'n> {
let mut extends = None;
let mut blocks = Vec::new();
let mut macros = HashMap::new();
let mut imports = HashMap::new();
for n in nodes {
match n {
Node::Extends(Expr::StrLit(extends_path)) => match extends {
Some(_) => panic!("multiple extend blocks found"),
None => {
extends = Some(config.find_template(extends_path, Some(path)));
}
},
def @ Node::BlockDef(_, _, _, _) => {
blocks.push(def);
}
Node::Macro(name, m) => {
macros.insert(*name, m);
}
Node::Import(_, import_path, scope) => {
let path = config.find_template(import_path, Some(path));
imports.insert(*scope, path);
}
_ => {}
}
}
let mut check_nested = 0;
let mut nested_blocks = Vec::new();
while check_nested < blocks.len() {
if let Node::BlockDef(_, _, ref nodes, _) = blocks[check_nested] {
for n in nodes {
if let def @ Node::BlockDef(_, _, _, _) = n {
nested_blocks.push(def);
}
}
} else {
panic!("non block found in list of blocks");
}
blocks.append(&mut nested_blocks);
check_nested += 1;
}
let blocks: HashMap<_, _> = blocks
.iter()
.map(|def| {
if let Node::BlockDef(_, name, _, _) = def {
(*name, *def)
} else {
unreachable!()
}
})
.collect();
Context {
nodes,
extends,
blocks,
macros,
imports,
}
}
}
fn get_template_source(tpl_path: &Path) -> String {
match fs::read_to_string(tpl_path) {
Err(_) => panic!(
"unable to open template file '{}'",
tpl_path.to_str().unwrap()
),
Ok(mut source) => {
if source.ends_with('\n') {
let _ = source.pop();
}
source
}
}
}
#[cfg(test)]
mod tests {
use super::get_template_source;
use Config;
#[test]
fn get_source() {
let path = Config::new("").find_template("b.html", None);
assert_eq!(get_template_source(&path), "bar");
}
}
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