aws-sdk-dynamodb 1.109.0

// Code generated by software.amazon.smithy.rust.codegen.smithy-rs. DO NOT EDIT.

/// <p>Represents the input of a <code>GetItem</code> operation.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct GetItemInput {
    /// <p>The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub table_name: ::std::option::Option<::std::string::String>,
    /// <p>A map of attribute names to <code>AttributeValue</code> objects, representing the primary key of the item to retrieve.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub key: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    /// <p>This is a legacy parameter. Use <code>ProjectionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html">AttributesToGet</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub attributes_to_get: ::std::option::Option<::std::vec::Vec<::std::string::String>>,
    /// <p>Determines the read consistency model: If set to <code>true</code>, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.</p>
    pub consistent_read: ::std::option::Option<bool>,
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub return_consumed_capacity: ::std::option::Option<crate::types::ReturnConsumedCapacity>,
    /// <p>A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.</p>
    /// <p>If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.</p>
    /// <p>For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub projection_expression: ::std::option::Option<::std::string::String>,
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>). To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information on expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub expression_attribute_names: ::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>>,
}
impl GetItemInput {
    /// <p>The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub fn table_name(&self) -> ::std::option::Option<&str> {
        self.table_name.as_deref()
    }
    /// <p>A map of attribute names to <code>AttributeValue</code> objects, representing the primary key of the item to retrieve.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn key(&self) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>> {
        self.key.as_ref()
    }
    /// <p>This is a legacy parameter. Use <code>ProjectionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html">AttributesToGet</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    ///
    /// If no value was sent for this field, a default will be set. If you want to determine if no value was sent, use `.attributes_to_get.is_none()`.
    pub fn attributes_to_get(&self) -> &[::std::string::String] {
        self.attributes_to_get.as_deref().unwrap_or_default()
    }
    /// <p>Determines the read consistency model: If set to <code>true</code>, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.</p>
    pub fn consistent_read(&self) -> ::std::option::Option<bool> {
        self.consistent_read
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn return_consumed_capacity(&self) -> ::std::option::Option<&crate::types::ReturnConsumedCapacity> {
        self.return_consumed_capacity.as_ref()
    }
    /// <p>A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.</p>
    /// <p>If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.</p>
    /// <p>For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn projection_expression(&self) -> ::std::option::Option<&str> {
        self.projection_expression.as_deref()
    }
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>). To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information on expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expression_attribute_names(&self) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, ::std::string::String>> {
        self.expression_attribute_names.as_ref()
    }
}
impl GetItemInput {
    /// Creates a new builder-style object to manufacture [`GetItemInput`](crate::operation::get_item::GetItemInput).
    pub fn builder() -> crate::operation::get_item::builders::GetItemInputBuilder {
        crate::operation::get_item::builders::GetItemInputBuilder::default()
    }
}

/// A builder for [`GetItemInput`](crate::operation::get_item::GetItemInput).
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::default::Default, ::std::fmt::Debug)]
#[non_exhaustive]
pub struct GetItemInputBuilder {
    pub(crate) table_name: ::std::option::Option<::std::string::String>,
    pub(crate) key: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    pub(crate) attributes_to_get: ::std::option::Option<::std::vec::Vec<::std::string::String>>,
    pub(crate) consistent_read: ::std::option::Option<bool>,
    pub(crate) return_consumed_capacity: ::std::option::Option<crate::types::ReturnConsumedCapacity>,
    pub(crate) projection_expression: ::std::option::Option<::std::string::String>,
    pub(crate) expression_attribute_names: ::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>>,
}
impl GetItemInputBuilder {
    /// <p>The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    /// This field is required.
    pub fn table_name(mut self, input: impl ::std::convert::Into<::std::string::String>) -> Self {
        self.table_name = ::std::option::Option::Some(input.into());
        self
    }
    /// <p>The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub fn set_table_name(mut self, input: ::std::option::Option<::std::string::String>) -> Self {
        self.table_name = input;
        self
    }
    /// <p>The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub fn get_table_name(&self) -> &::std::option::Option<::std::string::String> {
        &self.table_name
    }
    /// Adds a key-value pair to `key`.
    ///
    /// To override the contents of this collection use [`set_key`](Self::set_key).
    ///
    /// <p>A map of attribute names to <code>AttributeValue</code> objects, representing the primary key of the item to retrieve.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn key(mut self, k: impl ::std::convert::Into<::std::string::String>, v: crate::types::AttributeValue) -> Self {
        let mut hash_map = self.key.unwrap_or_default();
        hash_map.insert(k.into(), v);
        self.key = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>A map of attribute names to <code>AttributeValue</code> objects, representing the primary key of the item to retrieve.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn set_key(mut self, input: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>) -> Self {
        self.key = input;
        self
    }
    /// <p>A map of attribute names to <code>AttributeValue</code> objects, representing the primary key of the item to retrieve.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn get_key(&self) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>> {
        &self.key
    }
    /// Appends an item to `attributes_to_get`.
    ///
    /// To override the contents of this collection use [`set_attributes_to_get`](Self::set_attributes_to_get).
    ///
    /// <p>This is a legacy parameter. Use <code>ProjectionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html">AttributesToGet</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn attributes_to_get(mut self, input: impl ::std::convert::Into<::std::string::String>) -> Self {
        let mut v = self.attributes_to_get.unwrap_or_default();
        v.push(input.into());
        self.attributes_to_get = ::std::option::Option::Some(v);
        self
    }
    /// <p>This is a legacy parameter. Use <code>ProjectionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html">AttributesToGet</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_attributes_to_get(mut self, input: ::std::option::Option<::std::vec::Vec<::std::string::String>>) -> Self {
        self.attributes_to_get = input;
        self
    }
    /// <p>This is a legacy parameter. Use <code>ProjectionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html">AttributesToGet</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_attributes_to_get(&self) -> &::std::option::Option<::std::vec::Vec<::std::string::String>> {
        &self.attributes_to_get
    }
    /// <p>Determines the read consistency model: If set to <code>true</code>, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.</p>
    pub fn consistent_read(mut self, input: bool) -> Self {
        self.consistent_read = ::std::option::Option::Some(input);
        self
    }
    /// <p>Determines the read consistency model: If set to <code>true</code>, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.</p>
    pub fn set_consistent_read(mut self, input: ::std::option::Option<bool>) -> Self {
        self.consistent_read = input;
        self
    }
    /// <p>Determines the read consistency model: If set to <code>true</code>, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.</p>
    pub fn get_consistent_read(&self) -> &::std::option::Option<bool> {
        &self.consistent_read
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn return_consumed_capacity(mut self, input: crate::types::ReturnConsumedCapacity) -> Self {
        self.return_consumed_capacity = ::std::option::Option::Some(input);
        self
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn set_return_consumed_capacity(mut self, input: ::std::option::Option<crate::types::ReturnConsumedCapacity>) -> Self {
        self.return_consumed_capacity = input;
        self
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn get_return_consumed_capacity(&self) -> &::std::option::Option<crate::types::ReturnConsumedCapacity> {
        &self.return_consumed_capacity
    }
    /// <p>A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.</p>
    /// <p>If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.</p>
    /// <p>For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn projection_expression(mut self, input: impl ::std::convert::Into<::std::string::String>) -> Self {
        self.projection_expression = ::std::option::Option::Some(input.into());
        self
    }
    /// <p>A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.</p>
    /// <p>If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.</p>
    /// <p>For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_projection_expression(mut self, input: ::std::option::Option<::std::string::String>) -> Self {
        self.projection_expression = input;
        self
    }
    /// <p>A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.</p>
    /// <p>If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.</p>
    /// <p>For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_projection_expression(&self) -> &::std::option::Option<::std::string::String> {
        &self.projection_expression
    }
    /// Adds a key-value pair to `expression_attribute_names`.
    ///
    /// To override the contents of this collection use [`set_expression_attribute_names`](Self::set_expression_attribute_names).
    ///
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>). To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information on expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expression_attribute_names(
        mut self,
        k: impl ::std::convert::Into<::std::string::String>,
        v: impl ::std::convert::Into<::std::string::String>,
    ) -> Self {
        let mut hash_map = self.expression_attribute_names.unwrap_or_default();
        hash_map.insert(k.into(), v.into());
        self.expression_attribute_names = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>). To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information on expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_expression_attribute_names(
        mut self,
        input: ::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>>,
    ) -> Self {
        self.expression_attribute_names = input;
        self
    }
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>). To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information on expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_expression_attribute_names(
        &self,
    ) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>> {
        &self.expression_attribute_names
    }
    /// Consumes the builder and constructs a [`GetItemInput`](crate::operation::get_item::GetItemInput).
    pub fn build(self) -> ::std::result::Result<crate::operation::get_item::GetItemInput, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::operation::get_item::GetItemInput {
            table_name: self.table_name,
            key: self.key,
            attributes_to_get: self.attributes_to_get,
            consistent_read: self.consistent_read,
            return_consumed_capacity: self.return_consumed_capacity,
            projection_expression: self.projection_expression,
            expression_attribute_names: self.expression_attribute_names,
        })
    }
}