问题
I'm developing an extension in VS Code to add language support for OpenSCAD (Script-based 3D modeling program). Currently, I have been working on a way to open / preview a file in OpenSCAD from VS Code, which I have been able to do successfully using my own preview manager.
My issue is that I want to add configurable naming formats when exporting an OpenSCAD file that use environment variables similar to those used in the tasks.json file. More info can be found here: https://code.visualstudio.com/docs/editor/variables-reference. As an example, taking the file test.scad and the export configuration ${fileBasenameNoExtension}.stl would export to the file test.stl.
Additionally, I want to add a custom variable, ${#} that would evaluate after all other variables as a unique version number to avoid duplicate exported files. Using the example file: test.scad and the export configuration, ${fileBasenameNoExtension}_${#}.stl, the extension would export to the file test_1.stl for the first time. Then, seeing that test_1.stl exists, it would export to test_2.stl, and so on. I implement similar functionality in all of my exporting utilities, so it is important I can implement it here.
Now that the intro is done, on to the actual question: To anyone who knows more about the VS Code API than I do, in order to best get the functionality described above, should I implement environment variable evaluation into my custom preview manager or reimplement the preview manager I have using tasks? Because I have already implemented my own preview manager that I am happy with, I would prefer to do the former. However, I have been unable to find any functions in the VS Code API that will evaluate the environment variables in a string. Is there a typescript function to evaluate environment variables in the API that I have missed?
If re-implementing this functionality using tasks is a better way to achieve my goal, would I have to sacrifice the control I have in my preview manager, such as being able to selectively kill open previews and dispalying active exports?
Or, is there a compromise that could use all of the power from tasks without losing any functionality I've already developed?
Link to branch of my extension's repository: https://github.com/Antyos/vscode-openscad/tree/PreviewModel
来源：https://stackoverflow.com/questions/61830915/evaluating-environment-variables-in-vs-code-extension