remove deprecated stuff from the stdlib; introduce better deprecation warnings

lib/pure/pegs.nim

@@ -74,8 +74,8 @@ type
     line: int                     ## line the symbol has been declared/used in
     col: int                      ## column the symbol has been declared/used in
     flags: set[NonTerminalFlag]   ## the nonterminal's flags
-    rule: Node                   ## the rule that the symbol refers to
-  Node {.shallow.} = object
+    rule: Peg                   ## the rule that the symbol refers to
+  Peg* {.shallow.} = object ## type that represents a PEG
     case kind: PegKind
     of pkEmpty..pkWhitespace: nil
     of pkTerminal, pkTerminalIgnoreCase, pkTerminalIgnoreStyle: term: string
@@ -83,13 +83,9 @@ type
     of pkCharChoice, pkGreedyRepSet: charChoice: ref set[char]
     of pkNonTerminal: nt: NonTerminal
     of pkBackRef..pkBackRefIgnoreStyle: index: range[0..MaxSubpatterns]
-    else: sons: seq[Node]
+    else: sons: seq[Peg]
   NonTerminal* = ref NonTerminalObj
 
-  Peg* = Node ## type that represents a PEG
-
-{.deprecated: [TPeg: Peg, TNode: Node].}
-
 proc term*(t: string): Peg {.nosideEffect, rtl, extern: "npegs$1Str".} =
   ## constructs a PEG from a terminal string
   if t.len != 1: