function extract(value){// Value will not have the expression property when we recurse.
var expression=value.expression||value;var type=expression.type;if(TYPES[type]===undefined){throw new Error(errorMessage(type));}return TYPES[type](expression);}
This function maps an AST value node
to its correct extractor function for its
given type.

This will map correctly for *all* possible expression types.

@param - value - AST Value object with type `JSXExpressionContainer`
@returns The extracted value.