Minus in w3c specification grammar

问题

What does the minus sign mean?

[14]    CharData ::= [^<&]* - ([^<&]* ']]>' [^<&]*)

From the w3c XML 1.0 specification

Also, where can I find information related to the syntax grammar? I'm having troubling finding the specification about the specification, if that makes any sense.

回答1:

Minus (-) is part of the Extended Backus-Naur Form (EBNF) notation used by the W3C XML Recommendation to define the formal grammar of XML:

Minus (-) in A - B matches any string that matches A but does not match B.

How to interpret the CharData production

[14] CharData ::= [^<&]* - ([^<&]* ']]>' [^<&]*)

[^<&]* is a string of any characters except the markup start characters, < and &.
']]>' is a literal string that is used to mark the end of CDATA.
([^<&]* ']]>' [^<&]*) is any string without < and & that doesn't contain the end marker for a CDATA section.

Therefore, altogether, CharData can be any string that doesn't contain the markup start characters, < and &, and doesn't contain the CDATA end marker, ]]>.

Minus in w3c specification grammar

问题

回答1:

How to interpret the CharData production

See also