Enum Type 

pub enum Type {
    Unspecified,
    Number,
    String,
    Bool,
    Array(TypeRef),
    Record(Record),
    Subject,
    App {
        args: FunArgs,
        result: TypeRef,
        aggregate: bool,
    },
    Date,
    Time,
    DateTime,
    Custom(StrRef),
}

Type information for expressions.

This enum represents the type of expressions in the EventQL type system. Types can be inferred during semantic analysis or left as Unspecified.

Variants

Unspecified

Type has not been determined yet

Number

Numeric type (f64)

String

String type

Bool

Boolean type

Array(TypeRef)

Array type

Record(Record)

Record (object) type

Subject

Subject pattern type

App

Function type with support for optional parameters.

The args field uses FunArgs to support both required and optional parameters. Optional parameters are indicated when args.needed < args.values.len().

Fields

args: FunArgs

Function argument types, supporting optional parameters

result: TypeRef

Return type of the function

aggregate: bool

Whether this is an aggregate function (operates on grouped data)

Date

Date type (e.g., 2026-01-03)

Used when a field is explicitly converted to a date using the AS DATE syntax.

Time

Time type (e.g., 13:45:39)

Used when a field is explicitly converted to a time using the AS TIME syntax.

DateTime

DateTime type (e.g., 2026-01-01T13:45:39Z)

Used when a field is explicitly converted to a datetime using the AS DATETIME syntax.

Custom(StrRef)

Custom type not defined in the EventQL reference

Used when a field is converted to a custom type registered in the analysis options. The string contains the custom type name as it appears in the query.

Examples

use eventql_parser::Session;

let mut session = Session::builder()
    .declare_custom_type("CustomTimestamp")
    .build();
let query = session.parse("FROM e IN events PROJECT INTO { ts: e.data.timestamp as CustomTimestamp }").unwrap();
let typed_query = session.run_static_analysis(query).unwrap();

Implementations

impl Type

pub fn as_record_or_panic(&self) -> Record

Returns the inner Record reference, panicking if this is not a Type::Record.

Trait Implementations

impl Clone for Type

fn clone(&self) -> Type

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Type

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

Formats the value using the given formatter.

impl Default for Type

fn default() -> Type

Returns the “default value” for a type.

impl Hash for Type

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Type

fn eq(&self, other: &Type) -> 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 Type

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for Type

impl Eq for Type

impl StructuralPartialEq for Type