5.18 Documentation Strings

The “docstring”, or documentation string, of a variable or function gives the description on it, given at its definition.

Function: documentation symbol structure value

Returns the documentation-string for symbol. It should be the name of a special variable, function, macro, or a special form. If it’s not a variable, then value should be the function itself, like a closure.

Returns nil when not found. This function is defined in rep.lang.doc module.

structure can be nil. It was required in the old syntax.

Docstring is stored in a very complicated way. Those from installed files are stored in DOC file. Others use the plist for the name. If it’s a special variable, then docstring is in documentation property, and a closure and a macro, in documentation#MODULE.