6.3 Compound Dictionary Values

If you want to associate a non-string value with a dictionary variable, then you will need to use a compound value. Compound dictionary values are derived using EIEIO from a base class for handling arbitrary data in a macro.

Type: srecode-dictionary-compound-value ¶

A compound dictionary value. Values stored in a dictionary must be a string, a dictionary for showing sections, or an instance of a subclass of this class.

Compound dictionary values derive from this class, and must provide a sequence of method implementations to convert into a string.

Your new subclass of the compound value needs to implement these methods:

Function: srecode-compound-toString cp function dictionary ¶

Convert the compound dictionary value cp to a string. If function is non-nil, then function is somehow applied to an aspect of the compound value. The function could be a fraction of some function symbol with a logical prefix excluded.

The next method is for dumping out tables during debugging.

Function: srecode-dump cp &optional indent ¶

Display information about this compound value.

Here is an example of wrapping a semantic tag in a compound value:

(defclass srecode-semantic-tag (srecode-dictionary-compound-value)
 ((prime :initarg :prime
 :type semantic-tag
 :documentation
 "This is the primary insertion tag.")
 )
 "Wrap up a collection of semantic tag information.
This class will be used to derive dictionary values.")
(cl-defmethod srecode-compound-toString ((cp srecode-semantic-tag)
 function
 dictionary)
 "Convert the compound dictionary value CP to a string.
If FUNCTION is non-nil, then FUNCTION is somehow applied to an
aspect of the compound value."
 (if (not function)
 ;; Just format it in some handy dandy way.
 (semantic-format-tag-prototype (oref cp :prime))
 ;; Otherwise, apply the function to the tag itself.
 (funcall function (oref cp :prime))
 ))

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