1 extern crate syntax; 2 extern crate syntax_pos; 3 4 use syntax::ast; 5 use syntax::parse; 6 use syntax::ptr::P; 7 use syntax::sess::ParseSess; 8 use syntax::source_map::FilePathMapping; 9 use syntax_pos::FileName; 10 11 use std::panic; 12 libsyntax_expr(input: &str) -> Option<P<ast::Expr>>13pub fn libsyntax_expr(input: &str) -> Option<P<ast::Expr>> { 14 match panic::catch_unwind(|| { 15 let sess = ParseSess::new(FilePathMapping::empty()); 16 sess.span_diagnostic.set_continue_after_error(false); 17 let e = parse::new_parser_from_source_str( 18 &sess, 19 FileName::Custom("test_precedence".to_string()), 20 input.to_string(), 21 ) 22 .parse_expr(); 23 match e { 24 Ok(expr) => Some(expr), 25 Err(mut diagnostic) => { 26 diagnostic.emit(); 27 None 28 } 29 } 30 }) { 31 Ok(Some(e)) => Some(e), 32 Ok(None) => None, 33 Err(_) => { 34 errorf!("libsyntax panicked\n"); 35 None 36 } 37 } 38 } 39 syn_expr(input: &str) -> Option<syn::Expr>40pub fn syn_expr(input: &str) -> Option<syn::Expr> { 41 match syn::parse_str(input) { 42 Ok(e) => Some(e), 43 Err(msg) => { 44 errorf!("syn failed to parse\n{:?}\n", msg); 45 None 46 } 47 } 48 } 49