register-value

Arguments: value &optional index

This function has been renamed register-lisp-value. The old name is maintained for backward compatibility. New code should use the new name.

The value is stored in the table of foreign values at the requested index, if index is given; or in a free slot if index is not given. Two values are returned: the index and the previous value at that index (or nil if there was no previous value at that index).

Note that there is a distinction between registering a symbol and its value. To register the value of a symbol, one wants to evaluate the symbol. To register the symbol object itself, one must quote it. Thus

(ff:register-value 'my-symbol) 

registers the symbol my-symbol, whereas

(ff:register-value my-symbol) 

registers the (current) value of my-symbol. If one registers the value of a symbol and subsequently the value is changed, the change will not be reflected in the value returned by lisp_value() in C (described in foreign-functions.htm). If one registers a symbol, one must use special macros in C to access the value of the symbol.

See ftype.htm for information on foreign types in Allegro CL and foreign-functions.htm for general information on foreign functions in Allegro CL.

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This page was not revised from the 10.0 page.
Created 2019.8.20.