Allow expected!() to accept a &'static str expr, not just a literal

Author: kevinmehall

peg-macros/ast.rs

@@ -84,7 +84,7 @@ pub enum Expr {
     MatchStrExpr(Box<SpannedExpr>),
     PositionExpr,
     QuietExpr(Box<SpannedExpr>),
-    FailExpr(Literal),
+    FailExpr(Group),
     PrecedenceExpr {
         levels: Vec<PrecedenceLevel>,
     },

peg-macros/grammar.rs

@@ -2778,7 +2778,7 @@ pub mod peg {
                                     let __choice_res = {
                                         let __seq_res =
                                             __parse_sp(__input, __state, __err_state, __pos);
-                                        match __seq_res { :: peg :: RuleResult :: Matched (__pos , sp) => { match :: peg :: ParseLiteral :: parse_string_literal (__input , __pos , "expected") { :: peg :: RuleResult :: Matched (__pos , __val) => { match :: peg :: ParseLiteral :: parse_string_literal (__input , __pos , "!") { :: peg :: RuleResult :: Matched (__pos , __val) => { match :: peg :: ParseLiteral :: parse_string_literal (__input , __pos , "(") { :: peg :: RuleResult :: Matched (__pos , __val) => { { let __seq_res = __parse_LITERAL (__input , __state , __err_state , __pos) ; match __seq_res { :: peg :: RuleResult :: Matched (__pos , s) => { match :: peg :: ParseLiteral :: parse_string_literal (__input , __pos , ")") { :: peg :: RuleResult :: Matched (__pos , __val) => { :: peg :: RuleResult :: Matched (__pos , (|| { FailExpr (s) . at (sp) }) ()) } :: peg :: RuleResult :: Failed => { __err_state . mark_failure (__pos , "\")\"") ; :: peg :: RuleResult :: Failed } } } :: peg :: RuleResult :: Failed => :: peg :: RuleResult :: Failed , } } } :: peg :: RuleResult :: Failed => { __err_state . mark_failure (__pos , "\"(\"") ; :: peg :: RuleResult :: Failed } } } :: peg :: RuleResult :: Failed => { __err_state . mark_failure (__pos , "\"!\"") ; :: peg :: RuleResult :: Failed } } } :: peg :: RuleResult :: Failed => { __err_state . mark_failure (__pos , "\"expected\"") ; :: peg :: RuleResult :: Failed } } } :: peg :: RuleResult :: Failed => :: peg :: RuleResult :: Failed , }
+                                        match __seq_res { :: peg :: RuleResult :: Matched (__pos , sp) => { match :: peg :: ParseLiteral :: parse_string_literal (__input , __pos , "expected") { :: peg :: RuleResult :: Matched (__pos , __val) => { match :: peg :: ParseLiteral :: parse_string_literal (__input , __pos , "!") { :: peg :: RuleResult :: Matched (__pos , __val) => { { let __seq_res = __parse_PAREN_GROUP (__input , __state , __err_state , __pos) ; match __seq_res { :: peg :: RuleResult :: Matched (__pos , s) => { :: peg :: RuleResult :: Matched (__pos , (|| { FailExpr (s) . at (sp) }) ()) } :: peg :: RuleResult :: Failed => :: peg :: RuleResult :: Failed , } } } :: peg :: RuleResult :: Failed => { __err_state . mark_failure (__pos , "\"!\"") ; :: peg :: RuleResult :: Failed } } } :: peg :: RuleResult :: Failed => { __err_state . mark_failure (__pos , "\"expected\"") ; :: peg :: RuleResult :: Failed } } } :: peg :: RuleResult :: Failed => :: peg :: RuleResult :: Failed , }
                                     };
                                     match __choice_res {
                                         ::peg::RuleResult::Matched(__pos, __value) => {

peg-macros/grammar.rustpeg

@@ -124,7 +124,7 @@ rule primary() -> SpannedExpr
   = sp:sp() "precedence" "!" "{" levels:precedence_level()**"--" "}" { PrecedenceExpr{ levels:levels }.at(sp) }
   / sp:sp() "position" "!" "(" ")" { PositionExpr.at(sp) }
   / sp:sp() "quiet" "!" "{" e:expression() "}" { QuietExpr(Box::new(e)).at(sp) }
-  / sp:sp() "expected" "!" "(" s:LITERAL() ")" { FailExpr(s).at(sp) }
+  / sp:sp() "expected" "!" s:PAREN_GROUP() { FailExpr(s).at(sp) }
   / &("_" / "__" / "___") sp:sp() name:IDENT() { RuleExpr(name, Vec::new()).at(sp) }
   / sp:sp() name:IDENT() "(" args:(rule_arg() ** ",") ")" { RuleExpr(name, args).at(sp) }
   / sp:sp() l:LITERAL() { LiteralExpr(l).at(sp) }

tests/run-pass/errors.rs

@@ -11,6 +11,8 @@ peg::parser!{ grammar parser() for str {
     pub rule q() = (quiet!{
         ("a" / "b" / "c") ("1" / "2")
     } / expected!("letter followed by number"))+
+
+    pub rule var(s: &'static str) = expected!(s)
 }}
 
 fn main() {
@@ -59,4 +61,8 @@ aaaabaaaa
     let err = parser::q("a1bb").unwrap_err();
     assert_eq!(err.location.offset, 2);
     assert_eq!(err.expected.to_string(), "one of EOF, letter followed by number");
+
+    let err = parser::var("", "asdf").unwrap_err();
+    assert_eq!(err.expected.to_string(), "asdf");
+
 }