Hi HN, I wrote an assembler for the LC-3. This is part of my journey of learning how to write a compiler. The assembler is written in Python, and tries to sti

Hi HN, I wrote an assembler for the LC-3. This is part of my journey of learning how to write a compiler. The assembler is written in Python, and tries to stick to as simple a subset of Python as possible (essentially, just functions and dictionaries with dot syntax sugar). All control flow leaf terminations are explicit (e.g. continue, break). Idiomatic Python style is not a goal. Rather, the goal is to minimize the amount of syntax knowledge needed to follow the code. The code could be made much shorter with some clever refactoring, but brevity is a non-goal. This trivial coding style will hopefully make hacking on the code more approachable for others just learning about lexers / parsers / assemblers / compilers. The assembler is a simple two-pass implementation: create the symbol table (determine the addresses of all labels) in pass 1, then generate the machine code in pass 2. This is described in chapter 8 of the LC-3 book (Introduction to Computing Systems: From Bits and Gates to C and Beyond). The LC-3 ISA consists of only 15 instructions, making this a simple task. One oddity is that the ISA is word-addressable, not byte-addressable. The lexer is a simple regex-based implementation, and the parser is simple recursive descent. This approach is described in Gary Bernhardt's "A Compiler From Scratch" https://www.destroyallsoftware.com/screencasts/catalog/a-compiler-from-scratch https://www.destroyallsoftware.com/screencasts/catalog/a-com... The lexer and parser output can be dumped (in JSON format) via command-line flags. Additionally, the assembler also _accepts_ pre-parsed JSON input. This allows one to build a custom assembly syntax front-end and use this assembler as the back-end: all they have to do is generate the appropriate JSON output. Again, hackability is a goal! (How I wish other compilers allowed AST input!) A good practice project would be a reimplementation in Golang, focusing on speed. If you enjoyed this, you may also enjoy my trivial lisp interpreter in C series: https://gist.github.com/cellularmitosis/d8d4034c82b0ef817913a01138b115bf https://gist.github.com/cellularmitosis/d8d4034c82b0ef817913... or my lang-related list of links: https://gist.github.com/cellularmitosis/1f55f9679f064bcff02905acb44ca510 https://gist.github.com/cellularmitosis/1f55f9679f064bcff029... Happy hacking!