Added AST introspection routines as a part of the standard library

tests/accept/compile/tdumpast.nim

@@ -1,29 +1,12 @@
 # Dump the contents of a PNimrodNode
 
 import macros
-
-proc dumpit(n: PNimrodNode): string {.compileTime.} = 
-  if n == nil: return "nil"
-  result = $n.kind
-  add(result, "(")
-  case n.kind
-  of nnkEmpty: nil # same as nil node in this representation 
-  of nnkNilLit:                  add(result, "nil")
-  of nnkCharLit..nnkInt64Lit:    add(result, $n.intVal)
-  of nnkFloatLit..nnkFloat64Lit: add(result, $n.floatVal)
-  of nnkStrLit..nnkTripleStrLit: add(result, $n.strVal)
-  of nnkIdent:                   add(result, $n.ident)
-  of nnkSym, nnkNone:            assert false
-  else:
-    add(result, dumpit(n[0]))
-    for j in 1..n.len-1:
-      add(result, ", ")
-      add(result, dumpit(n[j]))
-  add(result, ")")
   
 macro dumpAST(n: stmt): stmt = 
   # dump AST as a side-effect and return the inner node
-  echo dumpit(n)
+  echo n.prettyPrint
+  echo n.toYaml
+
   result = n[1]
   
 dumpAST: