S-Lang function to find defined symbols (functions and variables)
apropos( match )
apropos( match, namespace )
The S-Lang run-time library provides the _apropos() function
which returns a list of defined symbol names (i.e. functions and
variables) that contain a given string.
The Varmm apropos() function is a wrapper around this
function to make it simpler to use from the
ChIPS and Sherpa prompts.
When called with only one argument, apropos() searches for
all S-Lang functions and variables which match the argument
and are defined in the default namespace (which is called "Global").
Therefore will report on any symbol that contains the
string "state".
When called with two arguments, the search is
restricted to only those symbols defined in the given
namespace that match.
So, if the namespace "foo" is defined then
will report on any symbol that contains the
string "state" in the namespace "foo".
Any matches are printed to the standard output, which makes it
easy to use in interactive sessions. If you want more control
over the output then use the S-Lang intrinsic function _apropos().
chips> apropos("scale")
Found 6 matches in Global namespace:
chips_set_xscale chips_get_yscale chips_get_xscale
chips_get_zscale chips_set_yscale chips_set_zscale
In this example we find that there are six S-Lang symbols available in
ChIPS that contain the name scale.
It is not possible to tell from this output whether they are
functions or variables.
To find this out you can use either of the S-Lang intrinsic
functions is_defined() or _apropos():
chips> is_defined("chips_get_xscale")
2
In this example they all happen to be user-defined functions,
as indicated by the return value of 2 (see "ahelp is_defined"
for more information).
chips> apropos("version")
Found 5 matches in Global namespace:
_slang_version _varmm_version _slang_version_string
_chips_version_string _chips_version
The set of defined symbols depends on what modules have been loaded.
ChIPS, by default, has the ChIPS and Varmm modules loaded and, as shown
above, this provides a number of symbols (this time all read-only variables) that
contain the string "version" in their name.
However, we can change this by loading in more S-Lang modules
into ChIPS, as shown in the following example where we load
Sherpa into ChIPS and then see if the number of "version"
variables has changed:
chips> require("sherpa")
Abundances set to Anders & Grevesse
chips> apropos("version")
Found 9 matches in Global namespace:
_slxpa_version_string _slang_version sherpa_version
_varmm_version xpa_version _slxpa_version
_slang_version_string _chips_version_string _chips_version
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