I would like rename a variable dynamically, Is there any way to do this in perl.
Thanks
Praveen
Do you want to use a reference? This gives you a reference to an existing object. Probably good enough.
Or, do you want to use a Type Glob? This allows you to directly modify the symbol table. There's probably no good reason for using it these days, but it does let you give a new name to an existing variable at a very fundamental level.
Related
Is there an easy way to figure out all places where a variable or parameter is being utilised in annylogic. Trying to locate where each variable is used can be a pain during debugging.
Sure. Just "ignore" it in the properties and compile the model.
You will get a list of errors for all places where it is called. Double-click on each error and AnyLogic even takes you there :)
Else, you can also use the AnyLogic search functionality.
in order to get some relief for that pain if your model is too big, all your variables should be private and you create setters, so each time you change your variable, you required to use a set function.
This doesn't solve your question, but it tells you what to do in future models to make it easier for you
check this video
https://www.youtube.com/watch?v=gNBfdB6YF7o
I'm curious if there is a Swifty, safe way to use AVAsynchronousKeyValueLoading without having to hard code the keys I'm using. Specifically, I'd like to call loadValuesAsynchronously(forKeys:completionHandler:) with the key "availableMdiaCharacteristicsWithMediaSelectionOptions", but it currently isn't possible to get a String from any kind of KeyPath-based solution. I would love it if there was some kind of way to retrieve the name of a property in such a way that it would be checked at compile time whether the property exists. Is there such an API?
The solution was #keyPath. I for some reason thought that KeyPath had replaced #keyPath in Swift, but #keyPath(AVAsset. availableMediaCharacteristicsWithMediaSelectionOptions) gives the string "availableMediaCharacteristicsWithMediaSelectionOptions" which is exactly what I want.
In perl sources GvNAME and GvENAME. Both return name for given gv. But second stands for effective name.
Dumping names I have not seen the difference.
May someone clear what is the difference and provide example which shows it?
UPD
Because this is related to naming too. What is difference between HvNAME vs HvNAME_HEK
The "effective" means who create this gv.
For example your module Module:: define my_sub. Then this sub was imported into Main::.
So the sub name is Main::my_sub but effective name is Module::my_sub
I'm writing a Powershell script which is going to go out into a client's current source control system and do a mass rename on all of the files so that they follow a new naming convention.
Being the diligent TDD developer that I am, I started with putting together a PSUnit test case. At first I was thinking that I would pass in a string to my function for the file name (along with a couple of other relevant parameters) and then return a string. Then it occurred to me that I am going to need to break apart the file name into an extension and a base name. Since System.IO.FileInfo already has that functionality, I thought why not just pass in a file object instead of a string?
If I do that however, then I don't see how I can write my PSUnit test without it being reliant on an external resource (in this case, the file must exist for me to get the FileInfo object - or does it?).
Is there a "clean" way to handle this? How are others approaching these issues?
Thanks for any help or advice!
My suggestion is: Be pragmatic and pass in the base name and extension as two separate strings. For convenience reasons, you can provide an overload that accepts a FileInfo.
Ruby has this very interesting functionality in which when you create a class with 'Class.new' and assign it to a constant (uppercase), the language "magically" sets up the name of the class so it matches the constant.
# This is ruby code
MyRubyClass = Class.new(SuperClass)
puts MyRubyClass.name # "MyRubyClass"
It seems ruby "captures" the assignment and inserts sets the name on the anonymous class.
I'd like to know if there's a way to do something similar in Lua.
I've implemented my own class system, but for it to work I've got to specify the same name twice:
-- This is Lua code
MyLuaClass = class('MyLuaClass', SuperClass)
print(MyLuaClass.name) -- MyLuaClass
I'd like to get rid of that 'MyLuaClass' string. Is there any way to do this in Lua?
When assigning to global variables you can set a __newindex metamethod for the table of globals to catch assignments of class variables and do whatever is needed.
You can eliminate one of the mentions of MyLuaClass...
> function class(name,superclass) _G[name] = {superclass=superclass} end
> class('MyLuaClass',33)
> =MyLuaClass
table: 0x10010b900
> =MyLuaClass.superclass
33
>
Not really. Lua is not an object-orientated language. It can behave like one sometimes. But far from every time. Classes are not special values in Lua. A table has the value you put in it, no more. The best you can do is manually set the key in _G from the class function and eliminate having to take the return value.
I guess that if it REALLY, REALLY bothers you, you could use debug.traceback(), get a stack trace, find the calling file, and parse it to find the variable name. Then set that. But that's more than a little overkill.
With respect at least to Lua 5.2: You can capture assignments to A) the global table of a Lua State, as mentioned in a previous reply, and also B) to any other Lua Object whose __index and __newindex metamethods have been substituted (by replacing the metatable), this I can confirm as I'm currently using both these techniques to hook and redirect assignments made by Lua scripts to external C/C++ resource management.
There is a gotcha with regards to reading them back though, the trick is to NOT let the values be set in a Lua State.
As soon as they exist there, your hooks will fail to be called, so if you want to go down this path, you need to capture ALL get/set attempts, and NEVER store the values in a Lua State.