Module typeconv 

Maintains a catalog of valid casts between mz_repr::SqlScalarTypes, as well as other cast-related functions.

Macros

casts 🔒

Structs

CastImpl 🔒

The implementation of a cast.

CastTemplate 🔒

A cast template is a function that produces a Cast given a concrete input and output type and a failure mode. A template can return None to indicate that it is incapable of producing a cast for the specified types, or for the specified failure mode.

Enums

CastContext

Describes the context of a cast.

CastError

Error returned when a cast is not available or not allowed.

Constants

REG_STRING_CAST_TEMPLATE 🔒

STRING_REG_CAST_TEMPLATE 🔒

STRING to REG*

Statics

REGCLASS_TO_STRING 🔒

REGPROC_TO_STRING 🔒

REGTYPE_TO_STRING 🔒

STRING_TO_REGCLASS_COERCED 🔒

STRING_TO_REGCLASS_EXPLICIT 🔒

STRING_TO_REGPROC 🔒

STRING_TO_REGTYPE 🔒

VALID_CASTS 🔒

Functions

can_cast

Reports whether it is possible to perform a cast from the specified types.

extract_unary_stages_for_try_cast 🔒

The unary functions a strict cast from from applies to its input, innermost first, or None if the cast has any other shape. See CastTemplate::new for the shape a cast must have.

get_cast 🔒

Get casts directly between two SqlScalarTypes, with control over the allowed CastContext.

guess_best_common_type

Guesses the most-common type among a set of SqlScalarTypes that all members can be cast to. Returns None if a common type cannot be deduced.

plan_cast

Plans a cast between SqlScalarTypes, specifying which types of casts are permitted using CastContext.

plan_cast_with_failure_mode

Like plan_cast, but with the given failure mode. Under CastFailureMode::NullFallback every stage of the cast, including the intermediate string cast that string-like types route through, is wrapped so that a failure anywhere yields NULL.

plan_coerce

plan_coerce_with_failure_mode

Like plan_coerce, but the casts that coerce a literal to coerce_to use the given failure mode. TRY_CAST('abc' AS int4) reaches its cast through this coercion, so the mode has to apply here too.

plan_hypothetical_cast

Similar to plan_cast, but for situations where you only know the type of the input expression (from) and not the expression itself. The returned expression refers to the first column of some imaginary row, where the first column is assumed to have type from.

plan_hypothetical_cast_with_failure_mode

Similar to plan_hypothetical_cast, but with a CastFailureMode to specify behavior.

sql_impl_cast 🔒

Like func::sql_impl_func, but for casts.

sql_impl_cast_per_context 🔒

to_jsonb

Converts an expression to SqlScalarType::Jsonb.

to_string

Converts an expression to SqlScalarType::String.

valid_cast_base_type_pairs

The base type pairs that have an entry in the cast table, for tests that want to prove they exercised every one.

validate_range_element_type 🔒

Returns an error if the given type is not a supported range element type (PostgreSQL built-in range types: int32, int64, date, numeric, timestamp, timestamptz).

Type Aliases

Cast 🔒

A cast is a function that takes a ScalarExpr to another ScalarExpr.