Enum aws_sdk_dynamodb::model::ComparisonOperator

#[non_exhaustive]
pub enum ComparisonOperator {
    BeginsWith,
    Between,
    Contains,
    Eq,
    Ge,
    Gt,
    In,
    Le,
    Lt,
    Ne,
    NotContains,
    NotNull,
    Null,
    Unknown(UnknownVariantValue),
}

When writing a match expression against ComparisonOperator, it is important to ensure your code is forward-compatible. That is, if a match arm handles a case for a feature that is supported by the service but has not been represented as an enum variant in a current version of SDK, your code should continue to work when you upgrade SDK to a future version in which the enum does include a variant for that feature.

Here is an example of how you can make a match expression forward-compatible:

# let comparisonoperator = unimplemented!();
match comparisonoperator {
    ComparisonOperator::BeginsWith => { /* ... */ },
    ComparisonOperator::Between => { /* ... */ },
    ComparisonOperator::Contains => { /* ... */ },
    ComparisonOperator::Eq => { /* ... */ },
    ComparisonOperator::Ge => { /* ... */ },
    ComparisonOperator::Gt => { /* ... */ },
    ComparisonOperator::In => { /* ... */ },
    ComparisonOperator::Le => { /* ... */ },
    ComparisonOperator::Lt => { /* ... */ },
    ComparisonOperator::Ne => { /* ... */ },
    ComparisonOperator::NotContains => { /* ... */ },
    ComparisonOperator::NotNull => { /* ... */ },
    ComparisonOperator::Null => { /* ... */ },
    other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
    _ => { /* ... */ },
}

The above code demonstrates that when comparisonoperator represents NewFeature, the execution path will lead to the second last match arm, even though the enum does not contain a variant ComparisonOperator::NewFeature in the current version of SDK. The reason is that the variable other, created by the @ operator, is bound to ComparisonOperator::Unknown(UnknownVariantValue("NewFeature".to_owned())) and calling as_str on it yields "NewFeature". This match expression is forward-compatible when executed with a newer version of SDK where the variant ComparisonOperator::NewFeature is defined. Specifically, when comparisonoperator represents NewFeature, the execution path will hit the second last match arm as before by virtue of calling as_str on ComparisonOperator::NewFeature also yielding "NewFeature".

Explicitly matching on the Unknown variant should be avoided for two reasons:

• The inner data UnknownVariantValue is opaque, and no further information can be extracted.
• It might inadvertently shadow other intended match arms.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

BeginsWith

Between

Contains

Eq

Ge

Gt

In

Le

Lt

Ne

NotContains

NotNull

Null

Unknown(UnknownVariantValue)

Unknown contains new variants that have been added since this code was generated.

Implementations

impl ComparisonOperator

pub fn as_str(&self) -> &str

Returns the &str value of the enum member.

Examples found in repository

src/model.rs (line 7939)

    fn as_ref(&self) -> &str {
        self.as_str()
    }

src/json_ser.rs (line 2174)

pub fn serialize_structure_crate_model_expected_attribute_value(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::model::ExpectedAttributeValue,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_479) = &input.value {
        #[allow(unused_mut)]
        let mut object_480 = object.key("Value").start_object();
        crate::json_ser::serialize_union_crate_model_attribute_value(&mut object_480, var_479)?;
        object_480.finish();
    }
    if let Some(var_481) = &input.exists {
        object.key("Exists").boolean(*var_481);
    }
    if let Some(var_482) = &input.comparison_operator {
        object.key("ComparisonOperator").string(var_482.as_str());
    }
    if let Some(var_483) = &input.attribute_value_list {
        let mut array_484 = object.key("AttributeValueList").start_array();
        for item_485 in var_483 {
            {
                #[allow(unused_mut)]
                let mut object_486 = array_484.value().start_object();
                crate::json_ser::serialize_union_crate_model_attribute_value(
                    &mut object_486,
                    item_485,
                )?;
                object_486.finish();
            }
        }
        array_484.finish();
    }
    Ok(())
}

pub fn serialize_structure_crate_model_parameterized_statement(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::model::ParameterizedStatement,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_487) = &input.statement {
        object.key("Statement").string(var_487.as_str());
    }
    if let Some(var_488) = &input.parameters {
        let mut array_489 = object.key("Parameters").start_array();
        for item_490 in var_488 {
            {
                #[allow(unused_mut)]
                let mut object_491 = array_489.value().start_object();
                crate::json_ser::serialize_union_crate_model_attribute_value(
                    &mut object_491,
                    item_490,
                )?;
                object_491.finish();
            }
        }
        array_489.finish();
    }
    Ok(())
}

pub fn serialize_structure_crate_model_s3_bucket_source(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::model::S3BucketSource,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_492) = &input.s3_bucket_owner {
        object.key("S3BucketOwner").string(var_492.as_str());
    }
    if let Some(var_493) = &input.s3_bucket {
        object.key("S3Bucket").string(var_493.as_str());
    }
    if let Some(var_494) = &input.s3_key_prefix {
        object.key("S3KeyPrefix").string(var_494.as_str());
    }
    Ok(())
}

pub fn serialize_structure_crate_model_input_format_options(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::model::InputFormatOptions,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_495) = &input.csv {
        #[allow(unused_mut)]
        let mut object_496 = object.key("Csv").start_object();
        crate::json_ser::serialize_structure_crate_model_csv_options(&mut object_496, var_495)?;
        object_496.finish();
    }
    Ok(())
}

pub fn serialize_structure_crate_model_table_creation_parameters(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::model::TableCreationParameters,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_497) = &input.table_name {
        object.key("TableName").string(var_497.as_str());
    }
    if let Some(var_498) = &input.attribute_definitions {
        let mut array_499 = object.key("AttributeDefinitions").start_array();
        for item_500 in var_498 {
            {
                #[allow(unused_mut)]
                let mut object_501 = array_499.value().start_object();
                crate::json_ser::serialize_structure_crate_model_attribute_definition(
                    &mut object_501,
                    item_500,
                )?;
                object_501.finish();
            }
        }
        array_499.finish();
    }
    if let Some(var_502) = &input.key_schema {
        let mut array_503 = object.key("KeySchema").start_array();
        for item_504 in var_502 {
            {
                #[allow(unused_mut)]
                let mut object_505 = array_503.value().start_object();
                crate::json_ser::serialize_structure_crate_model_key_schema_element(
                    &mut object_505,
                    item_504,
                )?;
                object_505.finish();
            }
        }
        array_503.finish();
    }
    if let Some(var_506) = &input.billing_mode {
        object.key("BillingMode").string(var_506.as_str());
    }
    if let Some(var_507) = &input.provisioned_throughput {
        #[allow(unused_mut)]
        let mut object_508 = object.key("ProvisionedThroughput").start_object();
        crate::json_ser::serialize_structure_crate_model_provisioned_throughput(
            &mut object_508,
            var_507,
        )?;
        object_508.finish();
    }
    if let Some(var_509) = &input.sse_specification {
        #[allow(unused_mut)]
        let mut object_510 = object.key("SSESpecification").start_object();
        crate::json_ser::serialize_structure_crate_model_sse_specification(
            &mut object_510,
            var_509,
        )?;
        object_510.finish();
    }
    if let Some(var_511) = &input.global_secondary_indexes {
        let mut array_512 = object.key("GlobalSecondaryIndexes").start_array();
        for item_513 in var_511 {
            {
                #[allow(unused_mut)]
                let mut object_514 = array_512.value().start_object();
                crate::json_ser::serialize_structure_crate_model_global_secondary_index(
                    &mut object_514,
                    item_513,
                )?;
                object_514.finish();
            }
        }
        array_512.finish();
    }
    Ok(())
}

pub fn serialize_structure_crate_model_condition(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::model::Condition,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_515) = &input.attribute_value_list {
        let mut array_516 = object.key("AttributeValueList").start_array();
        for item_517 in var_515 {
            {
                #[allow(unused_mut)]
                let mut object_518 = array_516.value().start_object();
                crate::json_ser::serialize_union_crate_model_attribute_value(
                    &mut object_518,
                    item_517,
                )?;
                object_518.finish();
            }
        }
        array_516.finish();
    }
    if let Some(var_519) = &input.comparison_operator {
        object.key("ComparisonOperator").string(var_519.as_str());
    }
    Ok(())
}

pub const fn values() -> &'static [&'static str]

Returns all the &str values of the enum members.

Trait Implementations

impl AsRef<str> for ComparisonOperator

fn as_ref(&self) -> &str

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for ComparisonOperator

fn clone(&self) -> ComparisonOperator

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ComparisonOperator

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

Formats the value using the given formatter.

impl From<&str> for ComparisonOperator

fn from(s: &str) -> Self

Converts to this type from the input type.

impl FromStr for ComparisonOperator

type Err = Infallible

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for ComparisonOperator

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 Ord for ComparisonOperator

fn cmp(&self, other: &ComparisonOperator) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<ComparisonOperator> for ComparisonOperator

fn eq(&self, other: &ComparisonOperator) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<ComparisonOperator> for ComparisonOperator

fn partial_cmp(&self, other: &ComparisonOperator) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for ComparisonOperator

impl StructuralEq for ComparisonOperator

impl StructuralPartialEq for ComparisonOperator