Convert strings in a label to a function
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@VRonin The function evaluate() seems the one I need. However, JavaScript is totally new to me. I thought lambda function in C++ can do the same thing. I will post the question on other forums, and when I find the answer, I will share it with you guys.
@WuliTiger said in Convert strings in a label to a function:
I thought lambda function in C++ can do the same thing
No, C++ is not an interpreted language as already noted.
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@VRonin The function evaluate() seems the one I need. However, JavaScript is totally new to me. I thought lambda function in C++ can do the same thing. I will post the question on other forums, and when I find the answer, I will share it with you guys.
The only way to do this without using an embedded scripting language or a C++ interpreter (I heard Clang provides something in this direction), is indeed to write your own parser. If you know a bit about compiler theory (like in http://www.diku.dk/~torbenm/Basics/basics_lulu2.pdf) then you simply write your own interpreter that can evaluate whatever you want.
Note that it may take a bit more than a weekend to do so.
Qt has to stay free or it will die.
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The only way to do this without using an embedded scripting language or a C++ interpreter (I heard Clang provides something in this direction), is indeed to write your own parser. If you know a bit about compiler theory (like in http://www.diku.dk/~torbenm/Basics/basics_lulu2.pdf) then you simply write your own interpreter that can evaluate whatever you want.
Note that it may take a bit more than a weekend to do so.
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Embed a Python interpreter.
I believe this is perfectly doable/available (from C++).
The advantage is that Python/PyQt is ready-made to call Qt functions, so you gain immediate access to all things Qt in the GUI without any work!
Thinking about it, this is actually seriously possible/simple, I believe....
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Embed a Python interpreter.
I believe this is perfectly doable/available (from C++).
The advantage is that Python/PyQt is ready-made to call Qt functions, so you gain immediate access to all things Qt in the GUI without any work!
Thinking about it, this is actually seriously possible/simple, I believe....
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@WuliTiger said in Convert strings in a label to a function:
I have been starting to write an interpreter. lol
How about, before diving head first in this hell, you take a look at stuff like https://github.com/root-project/cling that's already done?
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@WuliTiger said in Convert strings in a label to a function:
@JonB I have been starting to write an interpreter. lol
Also, I don't really understand what you want the interpreter for? Is it to be able to call Qt UI stuff, perhaps from within your own app you are writing in Qt, or does it have nothing to do with Qt and you just happen to be in this forum? Is it to write code? Is it to write arbitrary control systems control stuff?
My point being, it's not obvious to me why/whether you would wish to write/use any kind of C++ interpreter in the first place? It would not be my first thought for anything to "allow end users to write code" or "type in the system model"...
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@WuliTiger said in Convert strings in a label to a function:
@JonB I have been starting to write an interpreter. lol
Also, I don't really understand what you want the interpreter for? Is it to be able to call Qt UI stuff, perhaps from within your own app you are writing in Qt, or does it have nothing to do with Qt and you just happen to be in this forum? Is it to write code? Is it to write arbitrary control systems control stuff?
My point being, it's not obvious to me why/whether you would wish to write/use any kind of C++ interpreter in the first place? It would not be my first thought for anything to "allow end users to write code" or "type in the system model"...
@JonB You are right. I am trying to write a GUI for arbitrary control systems. It seems useless. However, I am passionate about that. I am writing the interpret for myself. Almost done. I will post it on the forum or Github. Thanks for your kind advises.
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@JonB You are right. I am trying to write a GUI for arbitrary control systems. It seems useless. However, I am passionate about that. I am writing the interpret for myself. Almost done. I will post it on the forum or Github. Thanks for your kind advises.
@WuliTiger said in Convert strings in a label to a function:
@JonB You are right. I am trying to write a GUI for arbitrary control systems. It seems useless. However, I am passionate about that. I am writing the interpret for myself. Almost done. I will post it on the forum or Github. Thanks for your kind advises.
Is your main goal to allow the user to insert arbitrary UI/code at runtime? If so, using Qt Quick might be easier. QML files can be interpreted at run-time (although this is usually considered a security risk).
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If you guys are still interested in the topic. See https://github.com/chalkwu/control-system.
I think it is a basic DIY solution. Cheers.
