mylang-compiler 1.0.0

MyLang — a statically-typed language that compiles to Python

MyLang Compiler

A statically-typed programming language that compiles to Python — built from scratch in Python with zero dependencies.

Install

pip install mylang-compiler

Quick Start

Create a file hello.myl:

program HelloWorld

  let name: text = "World"
  print "Hello, " + name + "!"

  thinkstep 2 ** 10

endprogram

Compile and run:

mylang hello.myl

Output:

Hello, World!
  [thinkstep] 2 ** 10  ==>  1024

CLI Flags

mylang hello.myl                  # compile + run (clean output)
mylang hello.myl --phases         # show all 7 compiler phases
mylang hello.myl --show-tokens    # Phase 1: token stream
mylang hello.myl --show-ast       # Phase 2: Abstract Syntax Tree
mylang hello.myl --show-symbols   # Phase 3: symbol table
mylang hello.myl --show-tac       # Phase 4: Three Address Code
mylang hello.myl --show-python    # Phase 5: generated Python source
mylang hello.myl --compile-only   # compile only, don't execute

The 7 Compiler Phases

Source (.myl)
    │
    ▼  Phase 1 — Lexical Analysis     tokens from raw text
    ▼  Phase 2 — Syntax Analysis      Abstract Syntax Tree
    ▼  Phase 3 — Semantic Analysis    type & scope checking
    ▼  Phase 4 — Intermediate Rep.    Three Address Code
    ▼  Phase 5 — Code Generation      emit Python source
    ▼  Phase 6 — Optimisation         constant folding, dead code
    ▼  Phase 7 — Execute              run via Python runtime

Language Features

Feature	Syntax
Variable	let age: num = 25
Function	fun add(a: num, b: num) as num
If / else	if x > 0 then ... else ... endif
For loop	for i from 1 to 10 step 1
While	while x > 0 begin ... end
Repeat N	repeat 5 times begin ... end
Do-while	do ... while cond enddo
Switch	switch x begin case 1: ... endswitch
Struct	struct Point begin x: num endstruct
Pointer	let p: ptr = &x then *p = 10
Type check	type(expression)
Debug step	thinkstep expression

Run Without Installing

python -m mylang hello.myl

Built For

Compiler Design coursework. All 7 phases are in separate, self-contained files under mylang/. 36/36 tests passing across all phases.