Selenium compiler

Selenium is a small esoteric language with a lunar / poetic surface and a strict, C-like core.
It compiles to C via a Python compiler.

🧶 Also available on Tangled

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Installation

pip install -e .

This installs the seleniumc command.

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Usage

# Compile to a C file
seleniumc hello.sel -o hello.c

# Compile, run with gcc, and execute immediately
seleniumc hello.sel --run

# Use a different C compiler
seleniumc hello.sel --run --cc clang

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Language reference

Types

Selenium	C equivalent	Notes
int	int	32-bit integer
float	double	64-bit float
bool	_Bool	true / false literals
char	char	single-quoted character
string	const char *	double-quoted literal
void	void	return type only

Comments

// single line comment
/* block
   comment */

Variables

wax int x = 5;       // mutable
seal int y = 10;     // immutable (const)

Variables are declared with wax (mutable) or seal (immutable), followed by type and name.
Top-level declarations become C globals. Declarations inside blocks are local.

Functions

ritual add(int a, int b) -> int {
    return a + b;
};

Functions are defined with ritual, take typed parameters, and specify a return type after ->.
Recursion is supported. Functions may be called before they are defined.

I/O

whisper expr;              // print any type, followed by newline
wax int x = read_int();    // read int from stdin
wax float f = read_float();
wax bool b = read_bool();
wax char c = read_char();

Control flow

// if / else
eclipse (condition) {
    ...
} shadow {
    ...
};

// while
tide (condition) {
    ...
};

// for
orbit (wax int i = 0; i < 10; i = i + 1) {
    ...
};

// switch
switch (expr) {
    case 1: { whisper "one"; break; };
    case 2: { whisper "two"; break; };
    default: { whisper "other"; break; };
};

break exits a loop or switch; continue skips to the next loop iteration.

Operators

Category	Operators
Arithmetic	+ - * / %
Comparison	< <= > >= == !=
Logical	&& || !
Bitwise	& | ^ << >>
Prefix	++ --
Ternary	cond ? then : else

Cast

wax float f = cast(float, 5);
wax int i = cast(int, 3.14);

Explicit type conversion between numeric types, bool, and char.

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Examples

Hello, World!

whisper "Hello, World!";

Functions

ritual fact(int n) -> int {
    eclipse (n <= 1) {
        return 1;
    } shadow {
        return n * fact(n - 1);
    };
};

whisper fact(10);

While loop

wax int i = 0;
tide (i < 5) {
    whisper i;
    i = i + 1;
};

Ternary

seal int a = 3;
seal int b = 7;
wax int max = a > b ? a : b;
whisper max;

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Project layout

selenium/
  lexer.py      – tokeniser (keywords, literals, operators)
  parser.py     – recursive-descent parser → AST
  ast.py        – AST node types
  sema.py       – type checker and semantic analyser
  codegen_c.py  – C code generator
  main.py       – CLI entry point
examples/       – sample .sel programs

Notes

• The compiler is intentionally strict — no implicit type coercion.
• All types must be declared explicitly.
• Top-level wax/seal declarations are emitted as C globals; everything else runs in main.
• Function definitions can appear anywhere at the top level; forward calls are supported.