4.2 KiB
Functions for lists
every
every(f, arr)
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
filter(f, arr)
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
find(f, arr)
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.
Furthermore 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
map(f, arr)
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
once(f, arr)
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
pick(f, arr)
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
some(f, arr)
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
unique
unique(arr)
Return a new list with unique items in it.
Example:
unique(["foo", "bar", "foo", "baz"]) // ["foo", "bar", "baz"]
PARAMETERS
| Name | Description | Default Value |
|---|---|---|
| arr | List to iterate over | none |
RETURNS
A new list with unique items