Sloperator

A SlopLang interpreter.

Language Reference

Files use the .slop extension and run with:

uv run sloperator.py path/to/program.slop

Example

— Comments start with an em dash. Statements end with sparkles.
clanker describe(count) {
    vibe count > 1 {
        ship “big slop”✨
    } nah {
        ship “small slop”✨
    }
}

slop MAX = 3✨
slop count = 0✨

ralph count < MAX {
    hallucinate(describe(count))✨
    count = count + 1✨
}

Prints small slop twice, then big slop.

The Slop Words

SlopLang	Conventional	Meaning
slop	let	Declare a mutable variable
clanker	fn	Define a function
vibe	if	Conditional
nah	else	Else branch
ralph	while	Loop while a condition is ✅
hallucinate	print	Print one value, then a newline
ship	return	Return one value from a function
✨	;	Statement terminator (required)
—	//	Start a line comment
“ ”	" "	String delimiters (straight quotes are a lexical error)
✅	true	Boolean true literal
❌	false	Boolean false literal

There are no other reserved words, and no break, continue, for, or else if.

Source Text

UTF-8, case-sensitive. Identifiers match [A-Za-z_][A-Za-z0-9_]*. Spaces, tabs, and newlines are whitespace; newlines do not end statements.

Emoji tokens are ✨ (U+2728), ✅ (U+2705), and ❌ (U+274C), each optionally followed by the variation selector U+FE0F, which some keyboards emit. ✨ must follow variable declarations, assignments, ship, and expression statements. It never follows a block's closing brace. — (U+2014) starts a comment that runs to end of line.

Strings open with “ (U+201C), close with ” (U+201D), and support escapes \n, \t, \”, and \\. A string cannot contain a raw newline. Unknown escapes and unterminated strings are lexical errors.

Values

Type	Examples	Notes
Number	0, 42, 9001	Arbitrary-precision integers
String	“hello”	Immutable Unicode text
Boolean	✅, ❌	Required by conditions
Nil	Result of a function with no ship	No source literal
Function	hallucinate, describe	Built-in or user-defined

No implicit conversions.

Variables

slop declares a mutable variable and requires an initializer. A scope cannot declare a name twice, but an inner block may shadow an outer name.

slop score = 10✨
slop LIMIT = 100✨
score = score + 5✨
score = score + 1✨

Assignment is a statement, not an expression: name = expression✨. It updates the nearest existing slop variable. Reading or assigning an undefined name is a runtime error.

Every brace block is a lexical scope. Assignment searches the current scope, then each enclosing scope.

Control Flow

Conditions take no parentheses and must be booleans; there is no truthiness.

vibe score >= 10 {
    hallucinate(“ship it”)✨
} nah {
    hallucinate(“keep working”)✨
}

ralph score > 0 {
    score = score - 1✨
}

nah must be followed by a block; nest a vibe for another condition. ralph checks its condition before each iteration.

A tree-walking interpreter for SlopLang, written in Python.

uv run sloperator.py examples/fib.slop

Layout

Path	What it is
sloperator.py	Command-line entrypoint
sloperator/lexer/	Source text to tokens
sloperator/parser/	Tokens to AST (ast.py holds the node definitions)
sloperator/evaluator/	Walks the AST: values, environments, the interpreter
sloperator/runner.py	Runs source through all three stages
docs/spec.md	The language specification
examples/	Example programs
tests/	Pytest suite
playground/	A tiny web server and editor page for running programs

Validation

uv run pytest              # tests
uv run ruff format --check # formatting
uv run ruff check          # linting
uv run ty check            # type checking

Playground

uv run playground/server.py

Then open http://localhost:8080.