def ntd(x, d):
nt = BGF.Nonterminal()
nt.setName(x)
w = d()
w.setExpr(BGF.Expression(nt))
return BGF.Expression(w)
# # ???
# else:
# prevline = alt[cx:]
# cx = len(alt)+10
# break
# nonterminals
if alt[cx] == '{':
curly += 1
cx += 1
continue
if alt[cx][0].isupper() or alt[cx][0] == '&':
if sym:
seq.add(sym)
if alt[cx][-1] == '+':
sym = BGF.Plus()
sym.setExpr(BGF.Nonterminal())
sym.data.setName(alt[cx][:-1])
elif alt[cx][-1] == '*':
sym = BGF.Star()
sym.setExpr(BGF.Nonterminal())
sym.data.setName(alt[cx][:-1])
elif alt[cx][-1] == '?':
sym = BGF.Optional()
sym.setExpr(BGF.Nonterminal())
sym.data.setName(alt[cx][:-1])
elif alt[cx] in layouts:
print 'Occurrence of layout nonterminal', alt[
cx], 'is disregarded.'
sym = BGF.Epsilon()
else:
sym = BGF.Nonterminal()