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chomp_macro::nibble! {
let opt(x) = _ | x;
let plus(x) = [plus](x . opt(plus));
let star(x) = [star](opt(x . star));
let Pattern_Whitespace = "\n"|" ";
let XID_Start =
"a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" |
"i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" |
"q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" |
"y" | "z" |
"A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" |
"I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" |
"Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" |
"Y" | "Z" ;
let XID_Continue =
XID_Start | "_" | "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
let literal_char = XID_Continue;
let ws = star(Pattern_Whitespace);
let must_ws = plus(Pattern_Whitespace);
let punctuated(x, p) = [rec](x . opt(p . ws . rec));
let list(x) = "(" . ws . [rec](x . opt("," . ws . opt(rec))) . ")";
let epsilon = "_";
let ident = XID_Start . star(XID_Continue);
let literal = "\"" . plus(literal_char) . "\"";
let parens(expr) = "(" . ws . expr . ")";
let fix(expr) = "[" . ws . ident . ws . "]" . ws . parens(expr);
let term(expr) =
epsilon . ws
| literal . ws
| parens(expr) . ws
| fix(expr) . ws
| ident . ws . opt(list(expr) . ws)
;
let cat(expr) = punctuated(term(expr), ".");
let alt(expr) = punctuated(cat(expr), "|");
let expr = [expr](alt(expr));
match expr;
}
#[test]
fn exp_epsilon() {
Ast::parse_str("_").unwrap();
}
#[test]
fn exp_literal() {
Ast::parse_str(r#""foo""#).unwrap();
}
#[test]
fn exp_cat() {
Ast::parse_str(r#""a" . "b""#).unwrap();
}
#[test]
fn exp_alt() {
Ast::parse_str(r#""a" | "b""#).unwrap();
}
#[test]
fn exp_ident() {
Ast::parse_str("foo").unwrap();
}
#[test]
fn exp_call() {
Ast::parse_str(r#"opt("foo")"#).unwrap();
}
#[test]
fn exp_fix() {
Ast::parse_str(r#"[rec](_ | "a" . rec)"#).unwrap();
}
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