better / more tests

Author: anmonteiro

formatTest/unit_tests/expected_output/infix.re

@@ -1202,3 +1202,5 @@ let x = a >< b;
 let (=\>) = (a, b) => a + b;
 
 let x = a =\> b;
+
+let (=>>) = (a, b) => a + b;

formatTest/unit_tests/input/infix.re

@@ -919,3 +919,5 @@ let x = a >< b;
 let (=\>) = (a, b) => a + b;
 
 let x = a =\> b;
+
+let (=>>) = (a, b) => a + b;

src/reason-parser/reason_lexer.mll

@@ -611,7 +611,7 @@ rule token = parse
             { INFIXOP0(lexeme_operator lexbuf) }
   (* `=\>` is treated especially due to conflicts with the function declaration
      syntax *)
-  | '\\'? '=' '\\'? '>' operator_chars*
+  | '\\'? "=\\>"
             { INFIXOP0(lexeme_operator lexbuf) }
   | '\\'? '@' operator_chars*
             { INFIXOP1(lexeme_operator lexbuf) }