Merge pull request #2503 from ReneSac/arrowLike

Restrict arrow-like operators to those ending with `->`, `~>` or `=>`

tests/parser/tstrongspaces.nim

@@ -15,6 +15,10 @@ true
 tester args
 all
 all args
+19
+-3
+false
+-2
 '''
 """
 
@@ -67,3 +71,13 @@ const
 echo tester & " " & args|"all"
 echo "all"  |  tester & " " & args
 echo "all"|tester & " " & args
+
+# Test arrow like operators. See also tests/macros/tclosuremacro.nim
+proc `+->`(a, b: int): int = a + b*4
+template `===>`(a, b: int): expr = a - b shr 1
+
+echo 3 +-> 2 + 2 and 4
+var arrowed = 3+->2 + 2 and 4  # arrowed = 4
+echo arrowed ===> 15
+echo (2 * 3+->2) == (2*3 +-> 2)
+echo arrowed ===> 2 + 3+->2