feat/schema: add lexer

schema/azschema.bnf

@@ -0,0 +1,18 @@
+string: '`' {.} '`' | '"' {.} '"';
+
+_bin_digit: '0' - '1';
+_oct_digit: _bin_digit | '2' - '7';
+_dec_digit: _oct_digit | '8' - '9';
+_hex_digit: _dec_digit | 'A' - 'F' | 'a' - 'f';
+_negative: '-';
+number: [_negative] '0' 'b' _bin_digit {_bin_digit}
+    | [_negative] '0' 'o' _oct_digit {_oct_digit}
+    | [_negative] _dec_digit {_dec_digit}
+    | [_negative] '0' 'x' _hex_digit {_hex_digit};
+
+_name_initial: 'A' - 'Z' | 'a' - 'z' | '_' | '~' | '!' | '@' | '#' | '$' | '%' | '^' | '&' | '*' | '-' | '_' | '+' | '=' | '?' | '/' | '.' | '\'';
+_name_char: _name_initial | _dec_digit;
+name: _name_initial {_name_char};
+
+!whitespace: ' ' | '\t' | '\n' | '\r';
+!comment: ';' {.} '\n';