ExSift (ex_sift v0.2.0)
MongoDB-style query filtering for Elixir collections.
ExSift allows you to filter Elixir enumerables using MongoDB-like query syntax.
Examples
# Simple filtering
ExSift.filter([%{name: "Alice", age: 30}, %{name: "Bob", age: 25}], %{name: "Alice"})
# => [%{name: "Alice", age: 30}]
# Using operators
ExSift.filter([%{age: 30}, %{age: 25}], %{age: %{"$gt" => 28}})
# => [%{age: 30}]Supported Operators
Comparison Operators
$eq- Equals$ne- Not equals$gt- Greater than$gte- Greater than or equal$lt- Less than$lte- Less than or equal
Logical Operators
$and- All conditions must match$or- At least one condition must match$nor- No conditions match$not- Negation
Array Operators
$in- Value in array$nin- Value not in array$all- Array contains all values$elemMatch- Array element matches query$size- Array has specific length
Other Operators
$exists- Field exists$regex- Regular expression match$type- Type checking$mod- Modulus operation
Performance
ExSift compiles queries into optimized Elixir functions. This means that for repeated filtering operations, the query parsing overhead is paid only once.
The compile/1 function returns a closure that can be used with Enum.filter/2, Enum.find/2,
or called directly on individual items.
Summary
Functions
Returns true if all items match the query.
Returns true if any item matches the query.
Compiles a query into a testing function.
Counts the number of items that match the query.
Filters an enumerable based on a MongoDB-style query.
Returns the first item that matches the query, or nil.
Tests if a single item matches a query.
Functions
Returns true if all items match the query.
Examples
iex> ExSift.all?([%{a: 1}, %{a: 2}], %{a: %{"$gte" => 1}})
true
iex> ExSift.all?([%{a: 1}, %{a: 2}], %{a: 1})
falseReturns true if any item matches the query.
Examples
iex> ExSift.any?([%{a: 1}, %{a: 2}], %{a: 2})
true
iex> ExSift.any?([%{a: 1}, %{a: 2}], %{a: 3})
falseCompiles a query into a testing function.
Returns a function that takes an item and returns true if it matches the query.
Examples
iex> tester = ExSift.compile(%{age: %{"$gt" => 25}})
iex> tester.(%{age: 30})
true
iex> tester.(%{age: 20})
falseCounts the number of items that match the query.
Examples
iex> ExSift.count([%{a: 1}, %{a: 2}, %{a: 1}], %{a: 1})
2Filters an enumerable based on a MongoDB-style query.
Returns a list of items that match the query.
Examples
iex> ExSift.filter([%{a: 1}, %{a: 2}], %{a: 1})
[%{a: 1}]
iex> ExSift.filter([%{a: 1}, %{a: 2}], %{a: %{"$gt" => 1}})
[%{a: 2}]Returns the first item that matches the query, or nil.
Examples
iex> ExSift.find([%{a: 1}, %{a: 2}], %{a: 2})
%{a: 2}
iex> ExSift.find([%{a: 1}, %{a: 2}], %{a: 3})
nilTests if a single item matches a query.
Examples
iex> ExSift.test(%{name: "Alice", age: 30}, %{age: 30})
true
iex> ExSift.test(%{name: "Bob", age: 25}, %{age: %{"$gte" => 30}})
false