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Diffstat (limited to 'autochomp/src/nibble.nb')
| -rw-r--r-- | autochomp/src/nibble.nb | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/autochomp/src/nibble.nb b/autochomp/src/nibble.nb new file mode 100644 index 0000000..fed3d46 --- /dev/null +++ b/autochomp/src/nibble.nb @@ -0,0 +1,67 @@ +let opt(x) = _ | x; +let plus(x) = [plus](x . opt(plus)); +let star(x) = opt(plus(x)); +let star_(base, step) = [rec](base | step . rec); + +let Pattern_Whitespace = "\t"|"\n"|"\x0B"|"\x0c"|"\r"|" "|"\u{85}"|"\u{200e}"|"\u{200f}"|"\u{2028}"|"\u{2029}"; + +let digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"; +let oct_digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7"; +let hex_digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" | + "a" | "b" | "c" | "d" | "e" | "f" | + "A" | "B" | "C" | "D" | "E" | "F" ; + +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 = + " " | "!" | "#" | "$" | "%" | "&" | "'" | + "(" | ")" | "*" | "+" | "," | "-" | "." | "/" | + "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | + "8" | "9" | ":" | ";" | "<" | "=" | ">" | "?" | + "@" | "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" | "{" | "|" | "}" | "~" | + "\\" . ("\"" | "'" | "n" | "r" | "t" | "\\" | "0" | + "x" . oct_digit . hex_digit | + "u{" . hex_digit . opt(hex_digit . opt(hex_digit . opt(hex_digit . opt(hex_digit . opt(hex_digit))))) . "}"); + +let ws = plus(Pattern_Whitespace); + +let punctuated(x, p) = [rec](x . opt(p . opt(ws) . opt(rec))); +let list(x) = "(" . opt(ws) . punctuated(x, ",") . ")"; + +let epsilon = "_"; +let ident = XID_Start . star(XID_Continue); +let literal = "\"" . plus(literal_char) . "\""; +let parens(expr) = "(" . opt(ws) . expr . ")"; +let fix(expr) = "[" . opt(ws) . ident . opt(ws) . "]" . opt(ws) . parens(expr); + +let term(expr) = + epsilon . opt(ws) + | literal . opt(ws) + | parens(expr) . opt(ws) + | fix(expr) . opt(ws) + | ident . opt(ws) . opt(list(expr) . opt(ws)) + ; + +let seq(expr) = punctuated(term(expr), "."); +let alt(expr) = punctuated(seq(expr), "|"); +let expr = [expr](alt(expr)); +let let = "let" . ws . ident . opt(ws) . opt(list(ident . opt(ws)) . opt(ws)) . "=" . opt(ws) . expr . ";"; +let goal = "match" . ws . expr . ";"; +match star_(goal, let); |