Support named capture groups

.ocamlformat

@@ -1,4 +1,4 @@
-version=0.19.0
+#version=0.19.0
 profile = conventional
 break-separators = after
 space-around-lists = false

examples/dune

@@ -1,5 +1,12 @@
 (executables
- (names tokenizer regressions complement subtraction repeat performance)
+ (names
+  tokenizer
+  regressions
+  complement
+  subtraction
+  repeat
+  performance
+  number_lexer)
  (libraries sedlex sedlex_ppx)
  (preprocess
   (pps sedlex.ppx))
@@ -46,3 +53,10 @@
   (:< performance.exe))
  (action
   (run %{<})))
+
+(rule
+ (alias runtest)
+ (deps
+  (:< number_lexer.exe))
+ (action
+  (run %{<})))

examples/number_lexer.ml

@@ -0,0 +1,93 @@
+let digit_2 = [%sedlex.regexp? '0' .. '1']
+let digit_8 = [%sedlex.regexp? '0' .. '7']
+let digit = [%sedlex.regexp? '0' .. '9']
+let digit_16 = [%sedlex.regexp? digit | 'A' .. 'F' | 'a' .. 'f']
+let prefix_2 = [%sedlex.regexp? "0b"]
+let prefix_8 = [%sedlex.regexp? "0o"]
+let prefix_16 = [%sedlex.regexp? "0x"]
+let sign = [%sedlex.regexp? "" | '+' | '-']
+let sign_op = [%sedlex.regexp? '+' | '-']
+let num_2 = [%sedlex.regexp? Plus digit_2]
+let num_8 = [%sedlex.regexp? Plus digit_8]
+let num_10 = [%sedlex.regexp? Plus digit]
+let num_16 = [%sedlex.regexp? Plus digit_16]
+
+let rec token buf =
+  let sub (a, b) = Sedlexing.Latin1.sub_lexeme buf a b in
+  match%sedlex buf with
+    (* {Integers} *)
+    | (sign as s), prefix_2, (num_2 as n) ->
+        Printf.printf "Bin %s%s\n" (sub s) (sub n);
+        token buf
+    | (sign as s), prefix_8, (num_8 as n) ->
+        Printf.printf "Oct %s%s\n" (sub s) (sub n);
+        token buf
+    | (sign as s), (num_10 as n) ->
+        Printf.printf "Dec %s%s\n" (sub s) (sub n);
+        token buf
+    | (sign as s), prefix_16, (num_16 as n) ->
+        Printf.printf "Hex %s%s\n" (sub s) (sub n);
+        token buf
+    (* {Fractions} *)
+    | (sign as s), prefix_2, (num_2 as n), '/', (num_2 as d) ->
+        Printf.printf "Bin %s%s/%s\n" (sub s) (sub n) (sub d);
+        token buf
+    | (sign as s), prefix_8, (num_8 as n), '/', (num_8 as d) ->
+        Printf.printf "Oct %s%s/%s\n" (sub s) (sub n) (sub d);
+        token buf
+    | (sign as s), (num_10 as n), '/', (num_10 as d) ->
+        Printf.printf "Dec %s%s/%s\n" (sub s) (sub n) (sub d);
+        token buf
+    | (sign as s), prefix_16, (num_16 as n), '/', (num_16 as d) ->
+        Printf.printf "Hex %s%s/%s\n" (sub s) (sub n) (sub d);
+        token buf
+    (* {Complex Numbers} *)
+    | (sign as s), prefix_2, (num_2 as r), (sign_op as o), (num_2 as i), 'i' ->
+        Printf.printf "Bin %s%s%s%si\n" (sub s) (sub r) (sub o) (sub i);
+        token buf
+    | (sign as s), prefix_8, (num_8 as r), (sign_op as o), (num_8 as i), 'i' ->
+        Printf.printf "Oct %s%s%s%si\n" (sub s) (sub r) (sub o) (sub i);
+        token buf
+    | (sign as s), (num_10 as r), (sign_op as o), (num_10 as i), 'i' ->
+        Printf.printf "Dec %s%s%s%si\n" (sub s) (sub r) (sub o) (sub i);
+        token buf
+    | (sign as s), prefix_16, (num_16 as r), (sign_op as o), (num_16 as i), 'i'
+      ->
+        Printf.printf "Hex %s%s%s%si\n" (sub s) (sub r) (sub o) (sub i);
+        token buf
+    (* {Others} *)
+    | Plus xml_blank -> token buf
+    | 128 .. 255 -> print_endline "Non ASCII"
+    | eof -> print_endline "EOF"
+    | _ -> failwith "Unexpected character"
+
+let () =
+  let lexbuf =
+    Sedlexing.Latin1.from_string
+      {|
+        123
+        +123
+        -123
+        0b01010101
+        -0b11110000
+        +0b11111111
+        0o12345670
+        +0o76543210
+        -0o17263540
+        0x123abcdef
+        -0x456DEFabc
+        +0x789ABCdef
+        123/456
+        -456/789
+        +987/654
+        0o777/100
+        +0o200/666
+        1+1i
+        1-1i
+        0x1f+2ei
+        +0x1f-2ei
+        0b10+11i
+        -0b10-11i
+      |}
+  in
+  token lexbuf

src/lib/sedlexing.mli

@@ -151,7 +151,7 @@ val next : lexbuf -> Uchar.t option
     lexer buffer and increments to current position. If the input stream
     is exhausted, the function returns -1.
     If a ['\n'] is encountered, the tracked line number is incremented.
-    
+
     This is a private API, it should not be used by code using this module's
     API and can be removed at any time. *)
 val __private__next_int : lexbuf -> int