String wrapper that supports meta-data...

[Jim foo.bar]

Hi all,

I often find myself wanting to attach meta-data to built-in Java classes 
and particularly to the 'String' class.  In a text-mining and NLP 
context, it is very useful for example to have a dictionary of strings 
where each string 'knows' its synonyms...Of course one can get around 
that by having a giant map from entities to synonyms. However, this adds 
an extra preprocessing step and also Java programmers enjoy this sort of 
encapsulation. Being able to store the synonyms as meta-data in the 
String object itself, essentially means that the object can be queried 
individually with no fuss...I'm not advocating any universally correct 
approaches here... I'm just sharing my experiences and where they led 
me...:-)
Both approaches (map-based, metadata-based) worked just fine...
In case anyone else is struggling to attach meta-data to any built-in 
Java type, here is what I did for the String class (file attached). It 
is very straight forward...basically you need to wrap the object in 
question and implement IObj...

Voila! Now MString instances support meta-data...YAY!

Jim

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import clojure.lang.IPersistentMap;
import clojure.lang.IObj;

//a wrapper around the String class that supports Clojure maps as meta-data
public final class MString implements IObj {

	private final String value;
	private final IPersistentMap meta;

	public MString(IPersistentMap meta, String value) {
		this.meta = meta;
		this.value = value;
	}
	public MString(String value) {
		this(null, value);
	}
	
	public String getString(){
	        return value;
	}

	public IObj withMeta(IPersistentMap meta) {
		return new MString(meta, value);
	}

	public IPersistentMap meta() {
		return meta;
	}
}