> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sdf.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Lambda Functions

## `reduce_agg`

Reduces all input values into a single value. inputFunction will be invoked for each non-null input value. In addition to taking the input value, inputFunction takes the current state, initially initialState, and returns the new state. combineFunction will be invoked to combine two states into a new state. The final state is returned.

*Supported Signatures*

```sql theme={null}
function reduce_agg($1, $10, function($10, $1, $10), function($10, $10, $10)) returns $10
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/aggregate.html#reduce_agg)

## `regexp_replace`

Removes every instance of the substring matched by the regular expression pattern from string.

*Examples:*

```sql examples.sql theme={null}
SELECT REGEXP_REPLACE('text foo another text', 'foo', 'bar') -- value 'text bar another text'
```

*Supported Signatures*

```sql theme={null}
function regexp_replace(varchar, joniregexp) returns varchar
function regexp_replace(varchar, joniregexp, varchar) returns varchar
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/regexp.html#regexp_replace)