Re: [Yaml-core] Re: Lookahead Required

[Clark C . E. <cc...@cl...>]

On Sun, Apr 14, 2002 at 12:17:09PM -0700, Neil Watkiss wrote:
|    1. It's not that simple. The _parser_ lookahead is theoretically
|       unbounded. For instance, in the following structure stream, the parser
|       would have to keep the entire tree on the input buffer before knowing
|       what to report:
| 
|       --- #YAML:1.0
|       - 1
|       - { foo: bar, baz: com }: nya nya!

Why?  As I see it, as soon as "- " token is received, the parser
can send the series-begin event.  The problem seems to be with the
second line... and we could fix this by making it illegal...

[094] nested_keyed_entry(n) ::= inline_leaf_node line_space *
                                keyed_entry_separator
                                value_node(>n)

Thus, with this "compressed" version, we could limit the lookahead
to exactly one inline_leaf_node.

|    NAME: Address
|    HASH:
|     + NAME: City
|       SCALAR: string
|     + NAME: State
|       SCALAR: string
|     + NAME: zipcode
|       SCALAR: integer

Interesting idea, although I think a one inline_leaf_node lookahead
is probably preferable to introducing yet another indicator.  ;)

Finding-ballence-is-hardly-yours,

Clark