Add menhir support (#781)

* Add menhir support

* Add menhir support

* Fixed bug with Menhir

---------

Co-authored-by: XAMPPRocky <[email protected]>
Co-authored-by: Basile Pesin <[email protected]>

languages.json

@@ -940,6 +940,16 @@
     "Max": {
       "extensions": ["maxpat"]
     },
+    "Menhir": {
+      "nested": true,
+      "quotes": [["\\\"", "\\\""]],
+      "line_comment": ["//"],
+      "multi_line_comments": [
+        ["(*", "*)"],
+        ["/*", "*/"]
+      ],
+      "extensions": ["mll", "mly", "vy"]
+    },
     "Meson": {
       "line_comment": ["#"],
       "quotes": [["'", "'"], ["'''", "'''"]],
@@ -1042,7 +1052,7 @@
     "OCaml": {
       "quotes": [["\\\"", "\\\""]],
       "multi_line_comments": [["(*", "*)"]],
-      "extensions": ["ml", "mli", "mll", "mly", "re", "rei"]
+      "extensions": ["ml", "mli", "re", "rei"]
     },
     "Odin": {
       "extensions": ["odin"],

tests/data/menhir.mly

@@ -0,0 +1,47 @@
+// 47 lines 31 code 7 comments 9 blanks
+
+(* Example from the menhir development with instrumented comments.
+ * (* Note: nested C style comments are not allowed. *)
+ * https://gitlab.inria.fr/fpottier/menhir/-/tree/master/demos/calc-alias *)
+
+%token<int> INT  "42"
+%token PLUS       "+"
+%token MINUS      "-"
+%token TIMES      "*"
+%token DIV        "/"
+%token LPAREN     "("
+%token RPAREN     ")"
+%token EOL
+
+(* Token aliases can be used throughout the rest of the grammar. E.g.,
+   they can be used in precedence declarations: *)
+
+%left "+" "-"       /* lowest " precedence */
+%left "*" "/"       /* medium precedence */
+%nonassoc UMINUS    // highest "precedence"
+
+%start <int> main
+
+%%
+
+main:
+| e = expr EOL
+    { e }
+
+(* Token aliases can also be used inside rules: *)
+
+expr:
+| i = "42"
+    { i }
+| "(" e = expr ")"
+    { e }
+| e1 = expr "+" e2 = expr
+    { e1 + e2 }
+| e1 = expr "-" e2 = expr
+    { e1 - e2 }
+| e1 = expr "*" e2 = expr
+    { e1 * e2 }
+| e1 = expr "/" e2 = expr
+    { e1 / e2 }
+| "-" e = expr %prec UMINUS
+    { - e }