Re: [Yaml-core] Specification production prefixes clarification

[Michael N. <Mic...@ya...>]

On Sunday 31 July 2005 11:18, Baptiste Lepilleur wrote:
>     The production prefixes are messing up with my mind. I don't really
> understand them:
>
>  [125] ns-l+block-node(n,c) ::=   ns-l+block-in-block(n,c) |
> ns-l+flow-in-block(n,c)
>
> ns-l+block-node: according to the production prefixes spec, 'ns-l' has the
> following meaning:
>
> ns-
> A production matching one or more characters starting and ending with *a
> non-space* character.
>
> l-
> A production matching one or more lines (shorthand for s-b-).
>
> And '-s-b':
>
> s-
> A production matching one or more characters starting and ending with *a
> space* character.
>
> b-
> A production matching a single line break.
>
> My understanding is that it is not possible for a production to match both
> 'ns-' and 's-' (and 'b-' implies ending with a space).
>
> What am I missing ?

I think that 'l-' is not really a shorthand of 's-b-' (in this point 
specification seems to be wrong), as we have 

[69]    l-comment        ::=     s-ignored-space* c-b-comment

and l-comment can starting with a non-space character.

I guess that  'l-' means that the production match sequence of characters, 
which ending with a line break.

Also we have the following:
-----------------------------
  X-Y-
    A production matching a sequence of one or more characters, starting with 
an X- character and ending with a Y- character.
  X+, X-Y+
    A production as above, with the additional property that the indentation 
level used is greater than the specified n parameter.
-----------------------------

So 's-b' means characters starting with a space and ending with a line break 
character.
'ns-l+block-node' means sequence which starts with a non-space and ends with a 
line break character.

Hope this helps.
Michael Nedzelsky