graphql_parser: drop the re dependency

CHANGES.md

@@ -1,3 +1,8 @@
+Unreleased
+---------------------------------
+
+- Drop the `re` dependency from `graphql_parser` (#221)
+
 0.14.0 2022-07-08
 ---------------------------------
 

graphql_parser.opam

@@ -17,7 +17,6 @@ depends: [
   "menhir" {build}
   "alcotest" {with-test & >= "0.8.1"}
   "fmt"
-  "re" {>= "1.5.0"}
 ]
 
 synopsis: "Library for parsing GraphQL queries"

graphql_parser/src/ast.ml

@@ -77,15 +77,20 @@ module Pp = struct
   let colon : unit Fmt.t = Fmt.(const string ":")
 
   let quote_string s =
-    let open Re in
-    s
-    |> replace_string (compile (char '\\')) ~by:"\\\\"
-    |> replace_string (compile (char '"')) ~by:"\\\""
-    |> replace_string (compile (char '\b')) ~by:"\\b"
-    |> replace_string (compile (char '\012')) ~by:"\\f"
-    |> replace_string (compile (char '\n')) ~by:"\\n"
-    |> replace_string (compile (char '\r')) ~by:"\\r"
-    |> replace_string (compile (char '\t')) ~by:"\\t"
+    let b = Buffer.create (String.length s) in
+    String.iter
+      (fun c ->
+        match c with
+        | '\\' -> Buffer.add_string b "\\\\"
+        | '"' -> Buffer.add_string b "\\\""
+        | '\b' -> Buffer.add_string b "\\b"
+        | '\012' -> Buffer.add_string b "\\f"
+        | '\n' -> Buffer.add_string b "\\n"
+        | '\r' -> Buffer.add_string b "\\r"
+        | '\t' -> Buffer.add_string b "\\t"
+        | c -> Buffer.add_char b c)
+      s;
+    Buffer.contents b
 
   let rec pp_value fmt = function
     | `Null -> Fmt.string fmt "null"

graphql_parser/src/block_string.ml

@@ -24,6 +24,23 @@ let get_block_string_indentation (s : string) : int =
   done;
   match !common_indent with None -> 0 | Some num -> num
 
+let split_lines (s : string) : string list =
+  let lines = ref [] in
+  let b = Buffer.create 32 in
+  let i = ref 0 in
+  let n = String.length s in
+  while !i < n do
+    ( match s.[!i] with
+    | ('\r' as c) | ('\n' as c) ->
+        if c == '\r' && try s.[!i + 1] == '\n' with _ -> false then incr i;
+        lines := Buffer.contents b :: !lines;
+        Buffer.clear b
+    | c -> Buffer.add_char b c );
+    incr i
+  done;
+  lines := Buffer.contents b :: !lines;
+  List.rev !lines
+
 exception NotBlank
 
 let is_blank (s : string) : bool =
@@ -33,14 +50,7 @@ let is_blank (s : string) : bool =
   with NotBlank -> false
 
 let dedent_block_string_value (s : string) : string =
-  let lines =
-    (let open Re in
-    split
-      (compile
-         (alt [ seq [ char '\r'; char '\n' ]; alt [ char '\n'; char '\r' ] ]))
-      s)
-    |> Array.of_list
-  in
+  let lines = split_lines s |> Array.of_list in
   let start_line = ref 0 in
   while !start_line < Array.length lines && is_blank lines.(!start_line) do
     incr start_line

graphql_parser/src/dune

@@ -7,6 +7,6 @@
 (library
  (name graphql_parser)
  (public_name graphql_parser)
- (libraries fmt re)
+ (libraries fmt)
  (flags
   (:standard -w -30)))