1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

//! This is a companion crate for `iref` providing two macros to build `'static`
//! IRIs and IRI references at compile time.
//!
//! ## Basic usage
//!
//! Use the `iri!` macro to build IRI statically, and the `iref!` macro to build
//! IRI references statically.
//!
//! ```rust
//! extern crate iref;
//! #[macro_use]
//! extern crate static_iref;
//!
//! use iref::{Iri, IriRef};
//!
//! const IRI: Iri<'static> = iri!("https://www.rust-lang.org/foo/bar#frag");
//! const IREF: IriRef<'static> = iref!("/foo/bar#frag");
//! ```

extern crate proc_macro;
extern crate iref;

use std::fmt;
use proc_macro::{TokenStream, TokenTree};
use iref::{Iri, IriRef};

struct Optional<T>(Option<T>);

impl<T: fmt::Display> fmt::Display for Optional<T> {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		match &self.0 {
			Some(t) => write!(f, "Some({})", t),
			None => write!(f, "None")
		}
	}
}

fn string_literal(tokens: TokenStream) -> Result<String, &'static str> {
	if let Some(token) = tokens.into_iter().next() {
		if let TokenTree::Literal(lit) = token {
			let str = lit.to_string();

			if str.len() >= 2 {
				let mut buffer = String::with_capacity(str.len()-2);
				for (i, c) in str.chars().enumerate() {
					if i == 0 || i == str.len()-1 {
						if c != '"' {
							return Err("expected string literal");
						}
					} else {
						buffer.push(c)
					}
				}

				Ok(buffer)
			} else {
				return Err("expected string literal");
			}
		} else {
			return Err("expected string literal");
		}
	} else {
		return Err("expected one string parameter");
	}
}

fn stringify_authority_parsing_data(p: Option<iref::parsing::ParsedAuthority>) -> String {
	match p {
		Some(p) => {
			format!(
"Some(::iref::parsing::ParsedAuthority {{
	userinfo_len: {},
	host_len: {},
	port_len: {}
}})
",
			Optional(p.userinfo_len), p.host_len, Optional(p.port_len))
		},
		None => {
			"None".to_string()
		}
	}
}

fn stringify_parsing_data(p: iref::parsing::ParsedIriRef) -> String {
	format!(
"::iref::parsing::ParsedIriRef {{
	scheme_len: {},
	authority: {},
	path_len: {},
	query_len: {},
	fragment_len: {}
}}",
	Optional(p.scheme_len), stringify_authority_parsing_data(p.authority), p.path_len, Optional(p.query_len), Optional(p.fragment_len))
}

/// Build an IRI reference with a `'static` lifetime at compile time.
///
/// This macro expects a single string literal token representing the IRI reference.
#[proc_macro]
pub fn iref(tokens: TokenStream) -> TokenStream {
	match string_literal(tokens) {
		Ok(str) => {
			if let Ok(iri_ref) = IriRef::new(str.as_str()) {
				let p = stringify_parsing_data(iri_ref.parsing_data());
				format!("unsafe{{::iref::IriRef::from_raw(b\"{}\", {})}}", str, p).parse().unwrap()
			} else {
				produce_error("invalid IRI reference")
			}
		},
		Err(msg) => produce_error(msg)
	}
}

/// Build an IRI with a `'static` lifetime at compile time.
///
/// This macro expects a single string literal token representing the IRI.
#[proc_macro]
pub fn iri(tokens: TokenStream) -> TokenStream {
	match string_literal(tokens) {
		Ok(str) => {
			if let Ok(iri) = Iri::new(str.as_str()) {
				let p = stringify_parsing_data(iri.as_iri_ref().parsing_data());
				format!("::iref::Iri::from_iri_ref(unsafe{{::iref::IriRef::from_raw(b\"{}\", {})}})", str, p).parse().unwrap()
			} else {
				produce_error("invalid IRI")
			}
		},
		Err(msg) => produce_error(msg)
	}
}

fn produce_error(msg: &str) -> TokenStream {
	format!("compile_error!(\"{}\")", msg).parse().unwrap()
}