zsh/Doc/Zsh/mod_parameter.yo

texinode(The parameter Module)(The sched Module)(The files Module)(Zsh Modules)
sect(The parameter Module)
cindex(parameters, special)
The tt(parameter) module gives access to some of the internal hash
tables used by the shell, by defining four special associative arrays.

startitem()
vindex(options)
item(tt(options))(
The keys for this associative array are the names of the options that
can be set and unset using the tt(setopt) and tt(unsetopt)
builtins. The value of each key is either the string tt(on) if the
option is currently set, or the string tt(off) if the option is unset.
Setting a key to one of these strings is like setting or unsetting
the option, respectively. Unsetting a key in this array is like
setting it to the value tt(off).
)
vindex(commands)
item(tt(command))(
This array gives access to the command hash table. The keys are the
names of external commands, the values are the pathnames of the files
that would be executed when the command would be invoked. Setting a
key in this array defines a new entry in this table in the same way as
with the tt(hash) builtin. Unsetting a key as in `tt(unset
"commands[foo]")' removes the entry for the given key from the command 
hash table.
)
vindex(functions)
item(tt(functions))(
This association maps function names to their definitions. Setting a
key in it is like defining a function with the name given by the key
and the body given by the value. Unsetting a key removes the
definition for the function named by the key.
)
vindex(parameters)
item(tt(parameters))(
The keys in this associative array are the names of the parameters
currently defined. The values are strings describing the type of the
parameter, in the same format used by the tt(t) parameter flag, see
ifzman(\
zmanref(zshexpn)
)\
ifnzman(\
noderef(Parameter Expansion)
)\
.
Setting or unsetting keys in this array is not possible.
)
enditem()