M2-T01: full ECMAScript value model (closes #27) by ncdevshiv · Pull Request #106 · ncdevshiv/R2N

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv · 2026-08-31T04:22:43Z

What

Closes#27. The Level-2 foundation: the complete ECMAScript value vocabulary with observable behavior (not just enum arms):

letb=BigInt(42);// 42n, typeof "bigint", 0n falsylets=Symbol("tag");// identity-distinct (s1 != s2 same key)leto=Object();// dynamic prop bag: o.name = "r2n"; o.name -> "r2n"// missing prop -> undefined; typeof "object"letadd=(a,b)=>a+b;// first-class Function: add(2,3) -> 5, add(1) -> NaNletu=undefined;// keyword literal, typeof "undefined", falsy

Value::Undefined (keyword literal — lowers to a literal, not an unbound var), BigInt (bounded i64; BigInt() conversion), Symbol (id+key; identity-distinct), Object (shared mutable bag — member get/set/index; missing prop → undefined), Function (first-class: JsExpr::Closure now evaluates to a real Function value — it was Null; call_value invokes with param binding, missing arg → undefined), External (opaque).
ECMA ToBoolean (undefined/null/±0/NaN/""/0n falsy), ToNumber (undefined→NaN, null→0, bool→0|1, string parse), typeof builtin, ECMA display.
Fixes a latent correctness issue: 1 + undefined was "non-number operand", now NaN (ECMA parity).

Verification

7 tests in tests/value_model.rs: undefined keyword + falsiness, full truthiness matrix, BigInt semantics, symbol identity, object dynamic bags, first-class functions, external/opaque invariants. Suite 170 green; clippy -D warnings clean; fmt clean; audit green. Records: M2 1/15 in progress, overall 55/106.

…unction/External) - Value::Undefined (keyword literal; typeof 'undefined') - Value::BigInt(i64) (bounded; BigInt() conversion from number/bool; 0n falsy; display 42n) - Value::Symbol { id, key } (identity-distinct; Symbol(key) builtin) - Value::Object (Rc<RefCell<Map>>): dynamic prop bag — Object() builtin, member get/set, index access, missing prop -> undefined - Value::Function { params, body }: first-class — Closure eval now yields a real Function value (was Null); call_value invokes with param binding (missing arg -> undefined) - Value::External(u64): opaque; truthy; typeof 'external' - ECMA ToBoolean + ToNumber (undefined->NaN, null->0, bool->0|1, string parse) + typeof builtin; 1 + undefined now NaN (was 'non-number operand') - 'undefined' keyword lowers to a literal (not an unbound var) 7 tests in tests/value_model.rs; suite 170 green; clippy/fmt/audit clean. Records: M2 in progress 1/15, 55/106 overall. Closes#27

ncdevshiv merged commit 9e9975f into mainAug 31, 2026
2 checks passed

ncdevshiv deleted the feat/m2-t01-value-model branch August 31, 2026 04:25