Tree @563aaeb (Download .tar.gz)
SixtyPical
SixtyPical is a very low-level programming language, similar to 6502 assembly, with static analysis through abstract interpretation.
In practice, this means it catches things like
- you forgot to clear carry before adding something to the accumulator
- a subroutine that you call trashes a register you thought was preserved
- you tried to write the address of something that was not a routine, to a jump vector
and suchlike. It also provides some convenient operations and abstractions based on common machine-language programming idioms, such as
- copying values from one register to another (via a third register when there are no underlying instructions that directly support it)
- explicit tail calls
- indirect subroutine calls
The reference implementation can execute, analyze, and compile SixtyPical programs to 6502 machine code.
It is a work in progress, currently at the proof-of-concept stage.
The current released version of SixtyPical is 0.6. The current development version of SixtyPical, unreleased as of this writing, is 0.7-PRE.
Documentation
- Design Goals — coming soon.
- SixtyPical specification
- SixtyPical history
- Literate test suite for SixtyPical syntax
- Literate test suite for SixtyPical execution
- Literate test suite for SixtyPical analysis
- Literate test suite for SixtyPical compilation
- 6502 Opcodes used/not used in SixtyPical
TODO
For 0.7:
low
andhigh
address operators (turnword
type intobyte
.)
For 0.8:
word table
type.vector table
type.- zero-page memory locations.
- indirect addressing.
For 0.9
- save registers on stack or in memory (this preserves them = not trashed)
At some point...
- initialized
byte table
memory locations - always analyze before executing or compiling, unless told not to
trash
instruction.interrupt
routines.- 6502-mnemonic aliases (
sec
,clc
) - other handy aliases (
eq
forz
, etc.) - have
copy
instruction able to copy a constant to a user-def mem loc, etc. - add absolute addressing in shl/shr, absolute-indexed for add, sub, etc.
- check and disallow recursion.
- automatic tail-call optimization (could be tricky, w/constraints?)
- re-order routines and optimize tail-calls to fallthroughs
Commit History
@563aaeba479496cff81ba6a6cb73983650d57e22
git clone https://git.catseye.tc/SixtyPical/
- Remove low/high byte operators until I've thought about it more. Chris Pressey 6 years ago
- Fix links in README. Chris Pressey 6 years ago
- Add uncommitted example source, and fix names of 2 others. Chris Pressey 7 years ago
- Low and high address operators, parsing and execution thereof. Chris Pressey 7 years ago
- Compile copy byte to byte and word to word. Chris Pressey 7 years ago
- word types, with syntax and analysis thereof Chris Pressey 7 years ago
- Split scanner off from parser module, into own module. Chris Pressey 7 years ago
- Initial value for locations: changed syntax, executes, compiles. Chris Pressey 7 years ago
- Spec and tests for initial values of locations. Chris Pressey 7 years ago
- Added tag 0.6 for changeset f89772f47de9 Chris Pressey 8 years ago