- vm: don't store symbol names in instructions to make optimizing the IR easier? but what about jumps to labels. And it's no longer readable by humans.
- vm: rather than being able to jump to any 'address' (IPTR), use 'blocks' that have entry and exit points -> even better dead code elimination possible too
- when the vm is stable and *if* its language can get promoted to prog8 IL, the variable allocation should be changed.
It's now done before the vm code generation, but the IL should probably not depend on the allocations already performed.
So the CodeGen doesn't do VariableAlloc *before* the codegen, but as a last step.
- make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as ``p8v_``? Or not worth it (most 3 letter opcodes as variables are nonsensical anyway)
then we can get rid of the instruction lists in the machinedefinitions as well?
- [problematic due to using 64tass:] add a compiler option to not remove unused subroutines. this allows for building library programs. But this won't work with 64tass's .proc ...
- Zig-like try-based error handling where the V flag could indicate error condition? and/or BRK to jump into monitor on failure? (has to set BRK vector for that)
- add special (u)word array type (or modifier?) that puts the array into memory as 2 separate byte-arrays 1 for LSB 1 for MSB -> allows for word arrays of length 256 and faster indexing
- ast: don't rewrite by-reference parameter type to uword, but keep the original type (str, array)
BUT that makes the handling of these types different between the scope they are defined in, and the
scope they get passed in by reference... unless we make str and array types by-reference ALWAYS? BUT that
makes simple code accessing them in the declared scope very slow because that then has to always go through
the pointer rather than directly referencing the variable symbol in the generated asm....
- rethink the whole "isAugmentable" business. Because the way this is determined, should always also be exactly mirrorred in the AugmentableAssignmentAsmGen or you'll get a crash at code gen time.
note: the new Ast doesn't need this any more so maybe we can get rid of it altogether in the old AST - but it's still used for something in the UnusedCodeRemover.
- rewrite expression tree evaluation such that it doesn't use an eval stack but flatten the tree into linear code that uses a fixed number of predetermined value 'variables'?
What if we were to re-introduce Structs in prog8? Some thoughts:
- can contain only numeric types (byte,word,float) - no nested structs, no reference types (strings, arrays) inside structs
- is just some syntactic sugar for a scoped set of variables -> ast transform to do exactly this before codegen
- no arrays of struct -- because too slow on 6502 to access those, rather use struct of arrays instead.
can we make this a compiler/codegen only issue? i.e. syntax is just as if it was an array of structs?
or make it explicit in the syntax so that it is clear what the memory layout of it is.
- ability to assign struct variable to another? this is slow but can be quite handy sometimes.
however how to handle this in a function that gets the struct passed as reference? Don't allow it there? (there's no pointer dereferencing concept in prog8)
- ability to be passed as argument to a function (by reference)?
however there is no typed pointer in prog8 at the moment so this can't be implemented in a meaningful way yet,
because there is no way to reference it as the struct type again. (current ast gets the by-reference parameter
type replaced by uword)
So-- maybe don't replace the parameter type in the ast? Should fix that for str and array types as well then
