Support conditional breakpoints

[TamaMcGlinn]

If anyone wants to help me in adding support for conditional breakpoints, please do.

For example, gdb will accept this command:

break filename:20 if strcmp(y, "hello") == 0

So the basic idea is to add a function like ./std.vim:351:function! vebugger#std#toggleBreakpoint(file,line) but which accepts an additional expression, which is provided in the mapping using input, for example, adding in plugin/vebugger.vim:75:

"	\'k':'exe "VBGaddConditionalBreakpointThisLine ".input("Conditional> ")',

If there is already a breakpoint on that line, this could give an error (the user should have done a toggle first to remove the breakpoint) - this has the advantage of not throwing away data (the condition) silently. On the other hand, it might be more intuitive to just remove the existing one first, effectively overwriting the condition.

You can already use :VBGrawWrite to achieve the conditional breakpoint, with the disadvantages:

• there is no highlighting of the line, since vebugger hasn't registered this as a breakpoint. subsequently 'toggling' the breakpoint in fact removes the conditional breakpoint and adds a regular one.
• you have to type in the name of the file and the current line number (this can be solved with %h and something to get the line number, and creating your own mapping)

[TamaMcGlinn]

Another very useful feature in this would be to display the condition somehow when the cursor is on the line of a conditional breakpoint.

[TamaMcGlinn]

I'm sure I've made important mistakes, as I never code in vimscript and my vimscript langserver isn't working, but I've put my first attempt up here: https://github.com/TamaMcGlinn/vim-vebugger/tree/feature/conditional_breakpoints