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>,
    },
    Le {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Gt {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Ge {
        lhs: Box<Expr>,
        rhs: Box<Expr>,
    },
    Not {
        operand: Box<Expr>,
    },
    And {
        operands: Vec<Expr>,
    },
    Or {
        operands: Vec<Expr>,
    },
    Exists {
        at: String,
    },
    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>,
    },
    Len {
        of: Box<Expr>,
    },
    In {
        needle: Box<Expr>,
        haystack: Box<Expr>,
    },
}

flow.ir Expr op.

Discriminated with op tag, deny_unknown_fields, rename_all = "snake_case".

Ops:

• read / literal: Path / Lit
• comparison: Eq / Ne / Lt / Le / Gt / Ge
• boolean: Not / And / Or
• existence: Exists (Path lookup that returns bool instead of erroring)
• arithmetic: Add / Sub / Mul / Div
• aggregate: Len (length of array / string / object) / In (membership in array)

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 — numeric lhs < rhs (both sides coerced to f64).

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Le

Le — numeric lhs <= rhs.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Gt

Gt — numeric lhs > rhs.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Ge

Ge — numeric lhs >= rhs.

Fields

lhs: Box<Expr>

rhs: Box<Expr>

Not

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

Fields

operand: Box<Expr>

And

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

Fields

operands: Vec<Expr>

Or

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

Fields

operands: Vec<Expr>

Exists

Exists — read a path; return true if it resolves, false if missing. Distinct from Path (which raises PathNotFound) and from IsNull (a present-but-null value resolves to true here).

Fields

at: String

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>

Len

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

Fields

of: Box<Expr>

In

In — true if needle equals any element of haystack (which must evaluate to an array).

Fields

needle: Box<Expr>

haystack: Box<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