Enum Operand 

pub enum Operand {
    Prop {
        var: String,
        field: String,
    },
    Lit(Value),
    Param(String),
    Var(String),
    FuncCall {
        name: String,
        args: Vec<Operand>,
    },
    BinArith {
        op: ArithOp,
        left: Box<Operand>,
        right: Box<Operand>,
    },
    Index {
        base: Box<Operand>,
        index: Box<Operand>,
    },
    Case {
        branches: Vec<(Expr, Operand)>,
        default: Option<Box<Operand>>,
    },
}

Variants

Prop

Fields

var: String

field: String

Lit(Value)

Param(String)

Var(String)

Bare variable reference (used in WITH … WHERE alias > 2).

FuncCall

Scalar function call: toLower(n.name), size(n.tags), type(r), etc.

Supported functions (case-insensitive): toLower, toUpper, size, coalesce, type, abs, round, textMatches, contains, startsWith, endsWith, toInteger, toFloat, toString, decay, key, id. Unknown names → named error at execution time listing the supported set (see SCALAR_FUNCS in exec.rs).

Fields

name: String

args: Vec<Operand>

BinArith

Arithmetic expression inside a function argument: abs(n.age - 27), round(n.score * 1.5). Supports +, -, *, /.

Fields

op: ArithOp

left: Box<Operand>

right: Box<Operand>

Index

List subscript: n.tags[0], n.location[1], $list[$i].

Evaluates base, which must be a Value::List, and returns the element at index. A negative index counts from the end (openCypher §3.4.4). An out-of-range index, a non-list base, or a non-integer index all evaluate to null rather than erroring, so a subscript behaves like a missing property.

Fields

base: Box<Operand>

index: Box<Operand>

Case

Generic CASE WHEN <cond> THEN <value> [WHEN …] [ELSE <value>] END. Evaluates each branch’s condition in order, returning the first matching value; the default (ELSE) or null if none match.

Fields

branches: Vec<(Expr, Operand)>

default: Option<Box<Operand>>

Trait Implementations

impl Clone for Operand

fn clone(&self) -> Operand

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Operand

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

Formats the value using the given formatter.

impl PartialEq for Operand

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Operand