diff -r adb8b1a1d517 -r e52ee17bca47 yml2/grammar.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/yml2/grammar.py	Thu Apr 08 14:37:11 2021 +0200
@@ -0,0 +1,110 @@
+# YML 2.7.0 language definition
+
+# written by VB.
+
+import re
+from .pyPEG import keyword, _and, _not
+
+# pyPEG:
+#
+#   basestring:     terminal symbol (characters)
+#   keyword:        terminal symbol (keyword)
+#   matchobj:       terminal symbols (regex, use for scanning symbols)
+#   function:       named non-terminal symbol, recursive definition
+#                   if you don't want naming in output, precede name with an underscore
+#   tuple:          production sequence
+#   integer:        count in production sequence:
+#                    0: following element is optional
+#                   -1: following element can be omitted or repeated endless
+#                   -2: following element is required and can be repeated endless
+#   list:           options, choose one of them
+#   _not:           next element in production sequence is matched only if this would not
+#   _and:           next element in production sequence is matched only if this would, too
+
+newSyntax = True
+
+def oldSyntax():
+    global newSyntax
+    newSyntax = False
+
+def _if(cond, val):
+    if cond:
+        return val
+    else:
+        return ()
+
+def listing(x):     return x, -1, (",", x)
+r = re.compile
+
+comment = [r(r"//.*"), r(r"/\*.*?\*/", re.S)]
+_symbol = r"(?=\D)\w(\w|:)*"
+symbol = r(_symbol, re.U)
+pointer = r(r"\*" + _symbol, re.U)
+ppointer = r(r"\*\*" + _symbol, re.U)
+macro = r(r"\%" + _symbol, re.U)
+reference = r(r"\&" + _symbol, re.U)
+
+NameStartChar = r''':|[A-Z]|_|[a-z]|[\u00C0-\u00D6]|[\u00D8-\u00F6]|[\u00F8-\u02FF]|[\u0370-\u037D]|[\u037F-\u1FFF]|[\u200C-\u200D]|[\u2070-\u218F]|[\u2C00-\u2FEF]|[\u3001-\uD7FF]|[\uF900-\uFDCF]|[\uFDF0-\uFFFD]'''
+NameChar = NameStartChar + r'''|-|\.|[0-9]|\u00B7|[\u0300-\u036F]|[\u203F-\u2040]'''
+
+_xmlSymbol = "(" + NameStartChar + ")(" + NameChar + ")*"
+xmlSymbol = r(_xmlSymbol)
+aliasSymbol = r(r"-|(" + _xmlSymbol + r")")
+
+literal = [r(r'""".*?"""', re.S), r(r"'''.*?'''", re.S), r(r"""0x[a-f0-9]+|-?\d+\.\d*|-?\.\d+|-?\d+|".*?"|'.*?'""")]
+filename = [("'", r(r"[^']*"), "'"), ('"', r(r'[^"]*'), '"'), r(r"[^\s;]+")]
+ws = r(r"\s+", re.U)
+
+def pyExp():        return "!", r(r"(!=|\\!|[^!])+"), "!"
+value = [literal, pyExp]
+
+def tagQuote():     return r(r"\].*|\<.*?\>")
+def lineQuote():    return r(r"\|.*")
+def quote():        return [r(r"\d*>.*"), (literal, 0, [";", "."])]
+def parm():         return [([xmlSymbol, pyExp, pointer, macro], "=", [value, pointer, symbol]), value, pointer]
+def parm_eq():      return [xmlSymbol, pyExp, pointer, macro], "=", [value, pointer, symbol]
+parm_eq.__name__ = "parm"
+_func = [symbol, ppointer, pointer, reference], _if(newSyntax, (-1, ("[", listing(parm), "]"))), 0, ("(", listing(parm), ")"), 0, listing(parm), -1, parm_eq
+def pythonCall():   return keyword("python"), _func, [";", "."]
+def declParm():     return [pointer, macro, xmlSymbol], 0, ("=", [literal, symbol])
+def alias():        return keyword("alias"), aliasSymbol
+def descend():      return r(r"[+@*]" + _symbol, re.U)
+def base():         return keyword("is"), symbol
+def shape():        return symbol
+def decl():         return symbol, 0, base, 0, ("<", listing(shape), ">"), -1, descend, _if(newSyntax, (-1, ("[", 0, listing(declParm), "]"))), 0, ("(", 0, listing(declParm), ")"), 0, alias, 0, content
+def python():       return [r(r"!!.*?!!", re.S), r(r"!.*")]
+def operator():     return 0, keyword("define"), keyword("operator"), literal, keyword("as"), r(r".*")
+def constant():     return 0, keyword("define"), [pointer, symbol], "=", literal, 0, [";", "."]
+def in_ns():        return keyword("in"), xmlSymbol, [_decl, ("{", -2, _decl, "}")]
+_decl = keyword("decl"), listing(decl), [";", "."]
+def textsection():  return r(r'(\|\|(\>*)(.*?)\|\|(\>*))\s*$', re.S | re.M)
+def textsectionu(): return r(r'(\>\>.*?\>\>)', re.S)
+def include():      return keyword("include"), 0, reverse, 0, [ktext, kxml], [(kpointer, pointer), filename], 0, [";", "."]
+def func():         return _func, 0, content
+def funclist():     return listing(func)
+_cmd = funclist, 0, [";", "."]
+_inner = [include, textsection, textsectionu, pythonCall, _cmd, quote, lineQuote, tagQuote, pyExp]
+_cc = "{", -1, _inner, "}"
+def content_plain(): return [ (_l, 0, _p, 0, _b, 0, _cc), (_p, 0, _b, 0, _cc), (_b, 0, _cc), _cc ]
+content_plain.__name__ = "content"
+def func_plain():   return _func, 0, content_plain
+func_plain.__name__ = "func"
+def flist_plain():  return -2, func_plain
+flist_plain.__name__ = "funclist"
+def xbase():        return flist_plain
+def generic():      return flist_plain
+def subscript():    return flist_plain
+def parentheses():  return "(", 0, funclist, ")"
+def fparm():        return flist_plain
+
+_l = _if(newSyntax, ("<", listing(generic), ">"))
+_p = _if(not newSyntax, parentheses), _if(newSyntax, ("(", 0, listing(fparm), ")"))
+_b = (":", listing(xbase))
+_c = [_inner, _cc]
+
+def content():      return [ (_l, 0, _p, 0, _b, 0, _c), (_p, 0, _b, 0, _c), (_b, 0, _c), _c ]
+def reverse():      return keyword("reverse")
+def ktext():        return keyword("text")
+def kxml():         return keyword("xml")
+def kpointer():     return keyword("pointer")
+def ymlCStyle():    return -1, [_decl, in_ns, include, python, operator, constant, tagQuote, lineQuote, quote, _cmd]