[DGD] Re: parse string difficulties

[Robert Forshaw]

It seems my limited understanding has been reconfirmed, since now I'm 
thinking about extending the datafile interpretation, I don't know what to 
do next. This is essentially the grammar that Erwin wrote, plus a few small 
changes:

"whitespace = /[\b\r\t ]+/\n" +
	    "newline    = /\n/\n" +
	    "word       = /[a-zA-Z0-9,\"]+/\n" +
	    "operator   = /[\\.\\+\\=\\-]+/\n" +

	    "SENTENCE   : OPERATION          ? dop_a\n" +
	    "SENTENCE   : SENTENCE OPERATION ? dop_b\n" +

	    "OPERATION  : word operator word newline ? dop_1\n" +
	    "OPERATION  : word operator      newline ? dop_2\n" +
	    "OPERATION  :      operator word newline ? dop_3\n"


Note that the "word" regexp now accepts " and , as valid symbols. What I 
want is, to add a fourth element to an 'OPERATION' element, and if it sees 
',' or '"' in an operator (specifically, the suffix-parameter), it will 
assume a certain type. If its a comma, it will assume an array, and set the 
third element as a comma delimited array and the fourth element as "array", 
if it is in double quotes, it will assume a string, and set the third 
element as a string (as it would normally) and the fourth element as 
"string". And finally have it normally assumes integer, setting the fourth 
element to "int", unless it contains symbols "a-Z" in which case it again 
assumes a string (and sets the fourth element accordingly). It seems very 
complicated and I'm not sure where to begin... I'm wondering whether it 
would be better to break it down into several parse_string operations, but 
ideally I'd like to at least know how it would be done with a single 
parse_string...

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