Enum Expr 

pub enum Expr {
    Path {
        at: String,
    },
    Lit {
        value: Value,
    },
    Eq {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Ne {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Lt {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Lte {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Gt {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Gte {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Not {
        arg: Box<Expr>,
    },
    And {
        args: Vec<Expr>,
    },
    Or {
        args: Vec<Expr>,
    },
    Exists {
        arg: Box<Expr>,
    },
    Add {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Sub {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Mul {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Div {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Mod {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Len {
        arg: Box<Expr>,
    },
    In {
        needle: Box<Expr>,
        haystack: Box<Expr>,
    },
    CallExtern {
        ref_: String,
        args: Vec<Expr>,
    },
}

flow.ir Expr op.

Discriminated with op tag, deny_unknown_fields, rename_all = "snake_case". Wire format (op tag / field names) follows the canonical flow-ir-lua schema (flow/ir/schema.lua) verbatim: gte/lte (not ge/le), args on and/or, arg on not/len/exists.

Ops:

• read / literal: Path / Lit
• comparison: Eq / Ne / Lt / Lte / Gt / Gte (numbers or strings)
• boolean: Not / And / Or
• existence: Exists (truthy iff arg evaluates to a non-null value)
• arithmetic: Add / Sub / Mul / Div / Mod
• aggregate: Len (length of array / string / object) / In (membership in array)
• hatch: CallExtern (host-registered pure function, resolved via Externs)

Variants

Path

Path — read a value from ctx by simple $.a.b.c form.

Fields

at: String

Lit

Lit — literal JSON value.

Fields

value: Value

Eq

Eq — boolean equality of two sub-expressions.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Ne

Ne — boolean inequality.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Lt

Lt — lhs < rhs. Both numbers (f64) or both strings (lexicographic), mirroring canonical Lua < semantics. Mixed / other types raise.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Lte

Lte — lhs <= rhs (canonical wire tag lte).

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Gt

Gt — lhs > rhs.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Gte

Gte — lhs >= rhs (canonical wire tag gte).

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Not

Not — boolean negation of arg (truthy-based; null/false → true).

Fields

arg: Box<Expr>

And

And — variadic boolean conjunction (short-circuit). Empty list → true.

Fields

args: Vec<Expr>

Or

Or — variadic boolean disjunction (short-circuit). Empty list → false.

Fields

args: Vec<Expr>

Exists

Exists — evaluate arg; true iff it resolves to a non-null value. A Path arg that raises PathNotFound yields false (canonical arg ~= nil semantics — JSON null maps to Lua nil).

Fields

arg: Box<Expr>

Add

Add — numeric lhs + rhs (f64).

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Sub

Sub — numeric lhs - rhs.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Mul

Mul — numeric lhs * rhs.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Div

Div — numeric lhs / rhs. Division by zero raises DispatcherError.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Mod

Mod — numeric lhs % rhs (Lua % semantics: result takes the sign of rhs). Modulo by zero raises DispatcherError.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Len

Len — length of arg: array → element count, string → char count, object → key count. Other types raise DispatcherError.

Fields

arg: Box<Expr>

In

In — true if needle equals any element of haystack (which must evaluate to an array). Rust-side extension (not in canonical schema).

Fields

needle: Box<Expr>

haystack: Box<Expr>

CallExtern

CallExtern — value-shape Hatch: resolve a host-injected pure function by opaque key via the Externs registry, apply it to evaluated args, return the value. The registered function MUST be pure (no side effects, no flow control) — see canonical doc/ir.md §call_extern.

Fields

ref_: String

args: Vec<Expr>

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Expr

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Expr

fn deserialize<__D>( __deserializer: __D, ) -> Result<Expr, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Expr

fn eq(&self, other: &Expr) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Expr

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Expr