[parser]: support for hex literals

Author: strub

src/ecLexer.mll

@@ -334,7 +334,9 @@ let upper   = ['A'-'Z']
 let lower   = ['a'-'z']
 let letter  = upper | lower
 let digit   = ['0'-'9']
+let xdigit  = ['0'-'9' 'a'-'f' 'A'-'F']
 let uint    = digit+
+let uxint   = "0x" xdigit+
 
 let ichar  = (letter | digit | '_' | '\'')
 let lident = (lower ichar*) | ('_' ichar+)
@@ -361,6 +363,7 @@ rule main = parse
   | tident       { [TIDENT (Lexing.lexeme lexbuf)] }
   | mident       { [MIDENT (Lexing.lexeme lexbuf)] }
   | uint         { [UINT (BI.of_string (Lexing.lexeme lexbuf))] }
+  | uxint        { [UINT (BI.of_string (Lexing.lexeme lexbuf))] }
 
   | (digit+ as n) '.' (digit+ as f) {
       let nv, fv = BI.of_string n, BI.of_string f in