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Monday, February 06, 2012

Using = and : binding operators to delineate structure

I have messed around with "pseudo-XML" a lot. Oh, heck, whop cares about the XML part, except that it is a standard?  Structured, simple, data.  Trying to make stuff human readable, but also parseable.

Here's a new-to-me trick:

I often use key=value pairs.

Sometimes I use name: value.

I.e. both = and : are nice ways of binding name and value.

How about:
n1: nA=vA, nB=vB, nC=vC
=>  nA=vA, nB=vB, nC=vC
or whatever way you want to express name/value in XML.

I.e. : as a binding operator that can bind to a list of name=value pairs

Or non-XML, if that's what tickles your fancy.  JSON?:
{ "n1": {"nA": "vA", "nB": "vB", "nC": "vC" } }
(BTW, if I ever declare that I am doing pseudo-JSON, it will be to have fewer quotes.)

{ n1: {nA: vA, nB: vB, nC: vC } }

The biggest difference between shell script languages and regular languages is quoting. "Barewords" are a big characteristic of scripting languages.

:s can bind until the next colon - i.e, all colons have the same strength
n1: nA=vA, nB=vB, n2: v2, n3: nX=vX, nY=vY
{ n1: { nA:vA, nB:vB}, n2:v2, n3: {nX:vX, nY: vY} }
To get more levels deep, would need brackets, or indentation. more operators: ::==

Heck, I'm not trying to define a full language here.  There are at least 3 perfectly good data languages - XML, JSON, S-expressions.

I just want to define some notation that is a bit more user friendly, but can fall back to the other notations if necessary.


nedbrek said...

Might I recommend "Tcl Object Notation"?

Andy "Krazy" Glew said...

Thanks, Ed. Yet another...

Anyway, I'll keep stealing ideas for my pseudo-object-notation (oo, I like that, PSON (Pseudo Object Notation).

It looks like the TCL object notatiin is one key value pair per line. I don't necessarily like that. Or ios it parity based, alternating key value?

Andy "Krazy" Glew said...

While we are at it, in Perl SQL I used plain old Perl:

{ key => value, key => [ array, value ], ...}


I admit that I just plain evaled it the first time around (although I did use Safe::eval

nedbrek said...

It is parity based, any whitespace works. You can include whitespace (in a key or value) using "my key" or {my key}. Curlies nest, while " runs to the next "