Functions for lists
every(<a href="#every-f">f</a>, <a href="#every-arr">arr</a>)
Check if every item of arr passes function f.
Example: every(lambda i: i.endswith(".js"), ["app.js", "lib.js"]) // True
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
True or False
filter(<a href="#filter-f">f</a>, <a href="#filter-arr">arr</a>)
Filter a list arr by applying a function f to each item.
Example: filter(lambda i: i.endswith(".js"), ["app.ts", "app.js", "lib.ts", "lib.js"]) // ["app.js", "lib.js"]
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
A new list containing items that passed the filter function.
find(<a href="#find-f">f</a>, <a href="#find-arr">arr</a>)
Find a particular item from list arr by a given function f.
Unlike pick, the find method returns a tuple of the index and the value of first item passing by f. Furhermore find does not fail if no item passes f. In this case (-1, None) is returned.
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
Tuple (index, item)
map(<a href="#map-f">f</a>, <a href="#map-arr">arr</a>)
Apply a function f with each item of arr and return a new list.
Example: map(lambda i: i*2, [1, 2, 3]) // [2, 4, 6]
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
A new list with all mapped items.
once(<a href="#once-f">f</a>, <a href="#once-arr">arr</a>)
Check if exactly one item in list arr passes the given function f.
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
True or False
pick(<a href="#pick-f">f</a>, <a href="#pick-arr">arr</a>)
Pick a particular item in list arr by a given function f.
Unlike filter, the pick method returns the first item found by f. If no item has passed f, the function will fail.
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
item
some(<a href="#some-f">f</a>, <a href="#some-arr">arr</a>)
Check if at least one item of arr passes function f.
Example: some(lambda i: i.endswith(".js"), ["app.js", "lib.ts"]) // True
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| f | Function to execute on every item | none |
| arr | List to iterate over | none |
RETURNS
True or False