Struct tidb_query_codegen::rpn_function::RpnFnAttr

struct RpnFnAttr {
    is_varg: bool,
    is_raw_varg: bool,
    nullable: bool,
    writer: bool,
    max_args: Option<usize>,
    min_args: Option<usize>,
    extra_validator: Option<TokenStream>,
    metadata_type: Option<TokenStream>,
    metadata_mapper: Option<TokenStream>,
    captures: Vec<Expr>,
}

Parses an attribute like #[rpn_fn(varg, capture = [ctx, output_rows]).

Fields

is_varg: bool

Whether or not the function is a varg function. Varg function accepts &[&Option<T>].

is_raw_varg: bool

Whether or not the function is a raw varg function. Raw varg function accepts &[ScalarValueRef].

nullable: bool

Whether or not the function needs extra logic on None value.

writer: bool

Whether or not to use writer / guard pattern.

max_args: Option<usize>

The maximum accepted arguments, which will be checked by the validator.

Only varg or raw_varg function accepts a range of number of arguments. Other kind of function strictly stipulates number of arguments according to the function definition.

min_args: Option<usize>

The minimal accepted arguments, which will be checked by the validator.

extra_validator: Option<TokenStream>

Extra validator.

metadata_type: Option<TokenStream>

Metadata type.

metadata_mapper: Option<TokenStream>

Metadata mapper.

captures: Vec<Expr>

Special variables captured when calling the function.

Trait Implementations

impl Debug for RpnFnAttr

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

Formats the value using the given formatter.

impl Default for RpnFnAttr

fn default() -> Self

Returns the “default value” for a type.

impl Parse for RpnFnAttr

fn parse(input: ParseStream<'_>) -> Result<Self>