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#![recursion_limit = "128"]
extern crate proc_macro;
extern crate proc_macro2;
extern crate syn;
#[macro_use]
extern crate quote;
extern crate regex;
#[macro_use]
extern crate log;
extern crate xml;
use proc_macro2::*;
use xml::reader::{EventReader, XmlEvent, ParserConfig};
use std::iter::once;
use std::io::{BufRead, Read};
#[proc_macro_attribute]
pub fn template(attr: proc_macro::TokenStream, item: proc_macro::TokenStream) -> proc_macro::TokenStream {
let attr = proc_macro2::TokenStream::from(attr);
let item = proc_macro2::TokenStream::from(item);
let mut file_ = String::new();
let mut attr = attr.into_iter();
while let Some(a) = attr.next() {
if format!("{}", a) == "path" {
if let (Some(a), Some(b)) = (attr.next(), attr.next()) {
if format!("{}", a) == "=" {
file_ = format!("{}", b)
}
}
} else {
println!("unknown attribute {:?}", a);
}
}
let cargo_dir = std::env::var("CARGO_MANIFEST_DIR").unwrap();
let mut file = std::path::Path::new(&cargo_dir).join("templates");
file.push(file_.trim_matches('"'));
info!("parsing {:?}", file);
let template = {
let mut f = std::fs::File::open(&file).unwrap();
let mut template = String::new();
f.read_to_string(&mut template).unwrap();
template
};
let re_amp = regex::Regex::new(r"(&[a-zA-Z]+;)|&").unwrap();
let template = re_amp.replace_all(&template, |cap: ®ex::Captures| {
if let Some(c) = cap.get(1) {
c.as_str().to_string()
} else {
"&".to_string()
}
});
let mut name = None;
let mut item = item.into_iter();
let mut item_ = Vec::new();
let mut spec = proc_macro2::TokenStream::new();
let mut spec2 = proc_macro2::TokenStream::new();
let mut is_name = true;
let mut last_was_name = false;
loop {
match item.next() {
Some(TokenTree::Ident(id)) => {
if id.to_string() == "struct" || id.to_string() == "enum" {
let it = item.next().unwrap();
name = Some(syn::Ident::new(&format!("{}", it), it.span()));
item_.push(TokenTree::Ident(id));
item_.push(it);
last_was_name = true;
} else {
item_.push(TokenTree::Ident(id));
}
}
None => break,
Some(TokenTree::Punct(p)) => {
if last_was_name {
if p.to_string() == "<" {
let mut level = 1;
spec.extend(once(TokenTree::Punct(p.clone())));
spec2.extend(once(TokenTree::Punct(p.clone())));
item_.push(TokenTree::Punct(p));
loop {
match item.next() {
Some(TokenTree::Punct(p)) => {
let pp = p.to_string();
spec.extend(once(TokenTree::Punct(p.clone())));
item_.push(TokenTree::Punct(p.clone()));
if pp == ">" {
level -= 1;
if level <= 0 {
spec2.extend(once(TokenTree::Punct(p.clone())));
break
}
} else if pp == "<" {
level += 1;
} else if pp == ":" {
is_name = false;
} else if pp == "," && level == 1 {
spec2.extend(once(TokenTree::Punct(p.clone())));
is_name = true;
} else if is_name {
spec2.extend(once(TokenTree::Punct(p.clone())));
}
}
Some(it) => {
spec.extend(once(it.clone()));
if is_name {
spec2.extend(once(it.clone()));
}
item_.push(it)
}
None => break,
}
}
} else {
item_.push(TokenTree::Punct(p));
}
} else {
item_.push(TokenTree::Punct(p))
}
}
Some(it) => {
item_.push(it)
}
}
}
let name = name.unwrap();
use std::iter::FromIterator;
let item = proc_macro2::TokenStream::from_iter(item_);
let tokens = walk(std::io::Cursor::new(template.as_bytes()));
let tok: TokenStream = tokens.parse().unwrap();
let file = file.to_str().unwrap();
let tokens = quote! {
impl #spec cuach::Render for #name #spec2 {
fn render_into(&self, w: &mut std::fmt::Write) -> Result<(), std::fmt::Error> {
let _ = include_bytes!(#file);
use std::fmt::Write;
use cuach::Render;
#(#tok)*
Ok(())
}
}
#item
};
debug!("{}", tokens);
proc_macro::TokenStream::from(tokens)
}
use std::fmt::Write;
fn walk<B: BufRead>(file: B) -> String {
let mut tokens = String::new();
let t0 = std::io::Cursor::new("<template>");
let t1 = std::io::Cursor::new("</template>");
let config = ParserConfig::new()
.ignore_comments(false);
let parser = EventReader::new_with_config(t0.chain(file).chain(t1), config);
let mut level = 0;
for e in parser {
match e {
Ok(XmlEvent::StartElement { name, attributes, .. }) => {
if level == 0 {
level += 1;
continue
}
level += 1;
use std::fmt::Write;
let mut s = format!("<{}", name);
for attr in attributes.iter() {
write!(&mut s, " {}=\"{}\"", attr.name.local_name, attr.value).unwrap();
}
write!(&mut s, ">").unwrap();
let arguments = arguments(&s);
for args in arguments {
match args {
Arg::Text(t) => writeln!(tokens, "w.write_str({:?})?;", t).unwrap(),
Arg::Arg(a) => writeln!(tokens, "(\n{}\n).render_into(w)?;", a).unwrap(),
}
}
}
Ok(XmlEvent::EndElement { name }) => {
level -= 1;
if level == 0 {
continue
}
writeln!(tokens, "w.write_str(\"</{}>\")?;", name).unwrap()
}
Ok(XmlEvent::Comment(contents)) => {
let contents = contents.replace("&", "&");
tokens.push_str(&contents);
tokens.push_str("\n");
}
Ok(XmlEvent::Characters(contents)) => {
let arguments = arguments(&contents);
for args in arguments {
match args {
Arg::Text(t) => {
let re = regex::Regex::new(r"\s+").expect("regex");
let t = re.replace_all(t, " ");
writeln!(tokens, "w.write_str({:?})?;", t).unwrap()
},
Arg::Arg(a) => writeln!(tokens, "({}).render_into(w)?;", a).unwrap(),
}
}
}
Ok(XmlEvent::Whitespace(w)) => {
if !w.chars().any(|x| x == '\n') {
writeln!(tokens, r#"w.write_str(" ")?;"#).unwrap()
}
}
Ok(XmlEvent::StartDocument { .. }) => {}
Ok(XmlEvent::EndDocument) => {}
Ok(XmlEvent::ProcessingInstruction { .. }) => {}
Ok(XmlEvent::CData(_)) => {}
Err(e) => {
panic!("{:?}", e);
}
}
}
tokens
}
enum Arg<'a> {
Text(&'a str),
Arg(&'a str),
}
fn arguments(s: &str) -> Vec<Arg> {
let re = regex::Regex::new(r"(\{\{)|(\}\})|(\{([^\}\n]+)\})").expect("regex");
let mut arguments = Vec::new();
let mut start = 0;
for cap in re.captures_iter(s) {
if let Some(cap2) = cap.get(3) {
let (a, _) = s.split_at(cap2.end());
let (a, _) = a.split_at(cap2.start());
if cap2.start() > start {
arguments.push(Arg::Text(a.split_at(start).1))
}
arguments.push(Arg::Arg(cap.get(4).unwrap().as_str()));
start = cap2.end();
}
}
if start < s.len() {
arguments.push(Arg::Text(s.split_at(start).1))
}
arguments
}