imcvampire / simple-compiler

Simple compiler

Setup

Requirements:

• Poetry for installing dependencies
  • Recommended installation method: the "official installer" i.e. curl -sSL https://install.python-poetry.org | python3 -

Install dependencies specified in pyproject.toml:

poetry install

If you have trouble with Poetry not picking up pyenv's python installation, try poetry env remove --all and then poetry install again.

Typecheck and run tests:

./check.sh

or individually:

poetry run mypy .
poetry run pytest -vv

Run the compiler on a source code file:

./compiler.sh COMMAND [path/to/source/code] [path/to/output]

where COMMAND may be one of these:

asm     ::  Compile to assembly
compile ::  Compile to binary

If no source code file is specified, the compiler will read from stdin. If no output file is specified, the compiler will write to stdout (for asm) or to compiled_program (for compile).

Language spec

An expression is defined recursively as follows, where E, E1, E2, … En represent some other arbitrary expression.

• Integer literal: a whole number between -264 and 263 - 1.
• Boolean literal: either true or false.
• Identifier: a word consisting of letters, underscores or digits, but the first character must not be a digit.
• Unary operator: either -E or not E.
• Binary operator: E1 op E2 where op is one of the following: +, -, *, /, %, ==, !=, <, <=, >, >=, and, or, =.
  • Operator = is right-associative.
  • All other operators are left-associative.
  • Precedences are defined below.
• Parentheses: (E), used to override precedence.
• Block: { E1; E2; ...; En } or { E1; E2; ...; En; } (may be empty, last semicolon optional).
  • Semicolons after subexpressions that end in } are optional.
• Untyped variable declaration: var ID = E where ID is an identifier.
• Typed variable declaration: var ID: T = E where ID is an identifier and T is a type expression (defined below).
• Constant declaration: const ID = E where ID is an identifier.
• Typed constant declaration: const ID: T = E where ID is an identifier and T is a type expression.
• If-then conditional: if E1 then E2
• If-then-else conditional: if E1 then E2 else E3
• While-loop: while E1 do E2
  • break and continue are supported.
  • break exits the innermost active loop, and continue goes back to its beginning.