[TESTS][LAMBDA][MINOR] Fix GRAMMAR

tests/lambda/GRAMMAR

 expr = id
-| integer
+| INTEGER
 | "`true"
 | "`false"
 | STRING
+| CHAR
 | abstr
 | "let" LIDENT ":" type_id "=" expr "in" expr ":" type_id
 | "if" expr "then" expr
@@ -42,8 +43,11 @@ abstr = "fun" id id ":" type_id params ":" type_id "->" expr
 ;;
 
 match_value = id ":" type_id
-| integer
+| INTEGER
+| "`true"
+| "`false"
 | STRING
+| CHAR
 | match_value "," match_value
 | match_value "::" match_value
 | "(" match_value ")"
@@ -80,6 +84,4 @@ complex_type_id = UIDENT (* [A-Z][A-Za-z0-9_]* *)
 | complex_type_id "->" complex_type_id
 | "[" complex_type_id "]"
 | "(" complex_type_id ")"
-;;
 
-integer = INTEGER (* [0-9]+ *)

tests/lambda/tests/src/compute.ml

@@ -70,6 +70,7 @@ let rec g_token n = function
       | "UIDENT" -> g_uident 3 ""
       | "STRING" -> "\"" ^ g_ident 3 "" ^ "\""
       | "INTEGER" -> string_of_int (Random.int 1000)
+      | "CHAR" -> "'" ^ Char.escaped(Char.chr (Random.int 128)) ^ "'"
       | _ ->
 	let l = Loc.start_line loc in
 	let cbegin = Loc.start_off loc - Loc.start_bol loc in