Specifiers are strings beginning with the character ‘#’. They perform additional operations in grammar productions or supply extra meaning to them.
Top-down template grammars support the following specifiers.
#su…A spur update mode switch.
Only the adaptive top-down parser atd-parser supports this specifier.
#dAn operator for deferring an input terminal symbol.
#pt-…A marker for the end of a PCFG production with terminal symbols at the right-hand side.
Only the adaptive bottom-up parser abu-parser supports this specifier.
#pn-…A marker for the end of a PCFG production with nonterminal symbols at the right-hand side.
Only the adaptive bottom-up parser abu-parser supports this specifier.
The rege-markup-cfg tool marks up PCFG productions in a bottom-up template grammar for subsequent conversion to a top-down template grammar by the rege-bottom-up tool.
The specifiers #su… and #d use the context of a sequence or grouping.