Struct Modifiers

pub(crate) struct Modifiers {
    is_monotone: Option<Expr>,
    sqlname: Option<SqlName>,
    preserves_uniqueness: Option<Expr>,
    inverse: Option<Expr>,
    negate: Option<Expr>,
    is_infix_op: Option<Expr>,
    output_type: Option<Path>,
    output_type_expr: Option<Expr>,
    could_error: Option<Expr>,
    propagates_nulls: Option<Expr>,
    introduces_nulls: Option<Expr>,
}

Modifiers passed as key-value pairs to the #[sqlfunc] macro.

Fields

is_monotone: Option<Expr>

An optional expression that evaluates to a boolean indicating whether the function is monotone with respect to its arguments. Defined for unary and binary functions.

sqlname: Option<SqlName>

The SQL name for the function. Applies to all functions.

preserves_uniqueness: Option<Expr>

Whether the function preserves uniqueness. Applies to unary functions.

inverse: Option<Expr>

The inverse of the function, if it exists. Applies to unary functions.

negate: Option<Expr>

The negated function, if it exists. Applies to binary functions.

is_infix_op: Option<Expr>

Whether the function is an infix operator. Applies to binary functions, and needs to be specified.

output_type: Option<Path>

The output type of the function, if it cannot be inferred. Applies to all functions.

output_type_expr: Option<Expr>

The output type of the function as an expression. Applies to binary functions.

could_error: Option<Expr>

Optional expression evaluating to a boolean indicating whether the function could error. Applies to all functions.

propagates_nulls: Option<Expr>

Whether the function propagates nulls. Applies to binary functions.

introduces_nulls: Option<Expr>

Whether the function introduces nulls. Applies to all functions.

Trait Implementations

impl Debug for Modifiers

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

Formats the value using the given formatter.

impl Default for Modifiers

fn default() -> Modifiers

Returns the “default value” for a type.

impl FromMeta for Modifiers

fn from_list(__items: &[NestedMeta]) -> Result<Self>

Create an instance from a list of nested meta items.

fn from_nested_meta(item: &NestedMeta) -> Result<Self, Error>

fn from_meta(item: &Meta) -> Result<Self, Error>

Create an instance from a syn::Meta by dispatching to the format-appropriate trait function. This generally should not be overridden by implementers.

fn from_none() -> Option<Self>

When a field is omitted from a parent meta-item, from_none is used to attempt recovery before a missing field error is generated.

fn from_word() -> Result<Self, Error>

Create an instance from the presence of the word in the attribute with no additional options specified.

fn from_value(value: &Lit) -> Result<Self, Error>

Create an instance from a literal value of either foo = "bar" or foo("bar"). This dispatches to the appropriate method based on the type of literal encountered, and generally should not be overridden by implementers.

fn from_expr(expr: &Expr) -> Result<Self, Error>

fn from_char(value: char) -> Result<Self, Error>

Create an instance from a char literal in a value position.

fn from_string(value: &str) -> Result<Self, Error>

Create an instance from a string literal in a value position.

fn from_bool(value: bool) -> Result<Self, Error>

Create an instance from a bool literal in a value position.