mm2-stdlib

mm2-stdlib is a helper library for MORK. It adds relational operators, boolean operations, and list manipulations (fold, car, cons, length, first, append, sort, etc.) without bloating the core MORK kernel. Since the main branch of MORK does not include these operations natively, integrating mm2-stdlib provides them in a modular way.

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Integration

To use mm2-stdlib with your MORK fork, apply the following four changes.

Step 1: Add bool deserialization to MORK

The upstream MORK library does not implement DeserializableExpr for bool. Open expr/src/macros.rs in your MORK project and add the following block after the impl DeserializableExpr for &str { ... } block:

impl DeserializableExpr for bool {
    #[inline(always)]
    fn advanced(e: Expr) -> usize {
        unsafe {
            let Tag::SymbolSize(arity) = byte_item(*e.ptr) else { panic!("wrong symbol for bool") };
            1usize + (arity as usize)
        }
    }

    #[inline(always)]
    fn check(e: Expr) -> bool {
        unsafe {
            let Tag::SymbolSize(arity) = byte_item(*e.ptr) else { return false; };
            let s = std::ptr::slice_from_raw_parts(e.ptr.add(1), arity as _);
            let bytes = s.as_ref().unwrap();
            bytes == b"true" || bytes == b"false"
        }
    }

    #[inline(always)]
    fn deserialize_unchecked(e: Expr) -> Self {
        unsafe {
            let Tag::SymbolSize(arity) = byte_item(*e.ptr) else { unreachable!() };
            let s = std::ptr::slice_from_raw_parts(e.ptr.add(1), arity as _);
            let bytes = s.as_ref().unwrap();
            bytes == b"true"
        }
    }
}

Step 2: Add mm2-stdlib as a dependency

Open kernel/Cargo.toml in your MORK workspace and add:

[dependencies]
mm2-stdlib = { git = "https://github.com/abnsol/mm2-stdlib" }

Step 3: Register the library in the kernel

Open kernel/src/sinks.rs and make two changes:

1. Add the import at the top of the file:

use mm2_stdlib;

2. Inside the PureSink constructor, register mm2-stdlib alongside the built-in pure functions:

impl Sink for PureSink {
    fn new(e: Expr) -> Self {
        let mut scope = EvalScope::new();
        pure::register(&mut scope);
        mm2_stdlib::register(&mut scope);  // <-- add this line
        PureSink { e, unique: PathMap::new(), scope }
    }
    // ...
}

Step 4: Unify the crate graph with [patch]

MORK's workspace already contains eval, eval-ffi, and mork-expr as path dependencies. When mm2-stdlib fetches the same crates via git, Cargo treats them as separate copies with incompatible types. Add a [patch] section in MORK's root Cargo.toml to redirect the git copies back to your local workspace versions:

[patch."https://github.com/trueagi-io/MORK"]
eval = { path = "experiments/eval" }
eval-ffi = { path = "experiments/eval-ffi" }
mork-expr = { path = "expr" }

For a complete working example, see the test-mm2stdlib branch on the author's fork.

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Features

MM2 function name	Arguments	Returns	Description
bool_from_string	(String)	Bool	Parse a boolean from a string.
and_bool, or_bool, xor_bool, implies_bool	(Bool, Bool)	Bool	Logical operators.
u8_from_string, u16_from_string, u32_from_string, u64_from_string, u128_from_string	(String)	u*	Parse unsigned integer from a string.
<op>_<type>	(Type, Type)	Bool	Numeric comparisons: lt, gt, le, ge, eq, ne for u8–u128, i8–i128, f32, f64.
length, size-atom	(List)	Number	Number of elements in a list.
car, car-atom, first, first-from-pair	(List)	Expr	First element of a list.
cdr, cdr-atom	(List)	List	Rest of the list after the first element.
second-from-pair	(List)	Expr	Second element of a list.
last	(List)	Expr	Last element of a list.
cons	(Expr, List)	List	Prepend an element to a list.
decons	(List)	(Expr, List)	Split list into head and tail.
append	(List, List)	List	Concatenate two lists.
reverse	(List)	List	Reverse a list.
index-atom	(Number, List)	Expr	Element at index (index first, then list).
is-member	(Expr, List)	Bool	Check membership.
exclude-item	(Expr, List)	List	Remove all instances of an element.
unique-atom	(List)	List	Remove duplicates.
union-atom	(List, List)	List	Set union.
intersection-atom	(List, List)	List	Set intersection.
subtraction-atom	(List, List)	List	Set subtraction.
min-atom, max-atom	(List)	Expr	Minimum / maximum numeric element.
sort-math	(List)	List	Numeric sort.
sort-atom	(List)	List	Lexicographic (byte) sort.
foldl, foldl-atom	(Func, Init, List)	Expr	Left fold over a list.

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Test

Download the .mm2 test files from the test/ directory and run them from your MORK workspace:

cargo run -p mork -- run path/to/and.mm2