Module signature 

Analysis of a #[sqlfunc]-annotated function’s signature.

These helpers read syn types and answer what a generated trait impl needs to know about the function it wraps: its associated types once generic parameters are erased, which input positions reject NULL, and the output type a polymorphic signature implies. Nothing here reads the attribute’s modifiers or the arity tables, so it stays a leaf of the crate.

Enums

GenericUsage 🔒

How a generic type parameter T appears in a type.

Functions

camel_case 🔒

Convert an identifier to a camel-cased identifier.

classify_generic_usage 🔒

Classifies how a generic type parameter appears in a type.

container_idents_match 🔒

Compare two container type paths by their ident segments (ignoring lifetimes and generic arguments). Two containers are “same” if their path idents match.

derive_output_type_for_generic 🔒

Derives an output_type_expr for a single generic parameter, which appears in the output type as output_usage.

derive_output_type_for_generics 🔒

Derives an output_type_expr TokenStream from the structural relationship between input types and the output type, based on where generic parameters appear.

element_type_expr 🔒

Generates a token stream that extracts the T-level SQL type from an input access expression, based on how T is used in that input.

elide_lifetimes 🔒

Replaces all lifetime parameters in a syn::TypePath with '_.

elide_lifetimes_in_type 🔒

Recursively replaces all lifetime parameters in a syn::Type with '_.

erase_all_generic_params 🔒

Erases all generic type parameters from a type, replacing each with Datum<'a>.

erase_generic_param 🔒

Replaces occurrences of a generic type parameter with Datum<'a> in a type.

find_generic_type_params 🔒

Extracts generic type parameters from a function signature. Returns an empty Vec if there are no type parameters.

has_receiver 🔒

Checks if the function takes a self receiver.

is_nullable_type 🔒

Checks if a parameter type accepts NULL.

is_option_wrapped 🔒

Returns whether the outermost wrapper of a type is Option.

is_variadic_arg 🔒

Checks whether a parameter’s type is Variadic<...> or OptionalArg<...>, which makes the function variadic regardless of parameter count.

is_variadic_type 🔒

Checks if a type is Variadic<T>.

last_is_arena 🔒

Checks if the last parameter of the function is a &RowArena.

non_nullable_position_checks 🔒

Generates per-position nullability checks for non-nullable parameters.

output_type 🔒

Determine the output type for a function. Returns an error if the function does not return a value.

patch_lifetimes 🔒

Recursively patches lifetimes in a type, adding 'a to references without a lifetime and recursing into generic arguments and tuples.

sql_args 🔒

The parameters that carry SQL arguments, which excludes a &self receiver and a trailing &RowArena.

type_contains_ident 🔒

Returns whether a type syntactically contains an identifier.

variadic_element_is_nullable 🔒

For a Variadic<T> type, checks if T accepts NULL.