module Genlex: Genlex
type
token =
| |
Kwd of |
| |
Ident of |
| |
Int of |
| |
Float of |
| |
String of |
| |
Char of |
The type of tokens. The lexical classes are: Int
and Float
for integer and floating-point numbers; String
for
string literals, enclosed in double quotes; Char
for
character literals, enclosed in single quotes; Ident
for
identifiers (either sequences of letters, digits, underscores
and quotes, or sequences of 'operator characters' such as
+
, *
, etc); and Kwd
for keywords (either identifiers or
single 'special characters' such as (
, }
, etc).
val make_lexer : string list -> char Stream.t -> token Stream.t
Construct the lexer function. The first argument is the list of
keywords. An identifier s
is returned as Kwd s
if s
belongs to this list, and as Ident s
otherwise.
A special character s
is returned as Kwd s
if s
belongs to this list, and cause a lexical error (exception
Stream.Error
with the offending lexeme as its parameter) otherwise.
Blanks and newlines are skipped. Comments delimited by (*
and *)
are skipped as well, and can be nested. A Stream.Failure
exception
is raised if end of stream is unexpectedly reached.