Slices

The Slices registry provides utilities for working with slice data structures, including functions for filtering, sorting, and transforming slices in a flexible manner.

You can easily import all the functions from the slices registry by including the following import statement in your code

import "github.com/go-sprout/sprout/registry/slices"

list

The function creates a list from the provided elements, collecting them into a single array-like structure.

Signature

List(values ...any) []any

Template Example

{{ 1, 2, 3 | list }} // Output: [1, 2, 3]

append

The function adds an element to the end of an existing list, extending the list by one item.

Signature

Append(v any, list any) ([]any, error)

Template Example

{{ ["a", "b"] | append "c"  }} // Output: ["a", "b", "c"], nil
{{ nil | append "c"  }} // Error

prepend

The function adds an element to the beginning of an existing list, placing the new item before all others.

Signature

Prepend(v any, list any) ([]any, error)

Template Example

{{ ["b", "c"] | prepend "a" }} // Output: ["a", "b", "c"]
{{ nil | prepend "c" }} // Error

concat

The function merges multiple lists into a single, unified list, combining all elements from the provided lists.

Signature

Concat(lists ...any) any

Template Example

{{ ["c", "d"] | concat ["a", "b"] }} // Output: ["a", "b", "c", "d"]

chunk

The function divides a list into smaller, equally sized chunks based on the specified size, breaking the original list into manageable sub-lists.

Signature

Chunk(size int, list any) ([][]any, error)

Template Example

{{ ["a", "b", "c", "d"] | chunk 2 }}
// Output: [["a", "b"], ["c", "d"]], nil
{{ chunk 2 nil }}
// Output: nil, error

uniq

The function removes duplicate elements from a list, ensuring that each element appears only once in the resulting list.

Signature

Uniq(list any) ([]any, error)

Template Example

{{ ["a", "b", "a", "c"] | mustUniq }} // Output: ["a", "b", "c"], nil
{{ nil | mustUniq }} // Error

compact

The function removes nil and zero-value elements from a list, leaving only non-empty and meaningful values.

Signature

Compact(list any) ([]any, error)

Template Example

{{ [0, 1, nil, 2, "", 3] | compact }} // Output: [1, 2, 3], nil
{{ nil | compact }} // Error

flatten

The function flattens a list into a single-dimensional array, removing nested lists and combining all elements into a single list.

Signature

Flatten(list any) ([]any, error)

Template Example

{{ flatten [[1, 2], [3, 4], 5] }} // Output: [1, 2, 3, 4, 5]
{{ flatten [[1, [2]], [3, 4], 5] }} // Output: [1, 2, 3, 4, 5]
{{ nil | flatten }} // Error

flattenDepth

The function flattens a list into a single-dimensional array up to a specified depth, removing nested lists and combining all elements into a single list up to the specified depth.

Signature

FlattenDepth(deep int, list any) ([]any, error)

Template Example

{{ [[1, [2]], [3, [4]], 5] | flattenDepth -1 }} // Output: [1, 2, 3, 4, 5]
{{ [[1, [2]], [3, [4]], 5] | flattenDepth 1 }} // Output: [1, [2], 3, [4], 5]
{{ nil | flattenDepth }} // Error

slice

The function extracts a portion of a list, creating a new slice based on the specified start and end indices.

Signature

Slice(indices ...any, list any) (any, error)

Template Example

{{ [1, 2, 3, 4, 5] | slice 1, 3 }} // Output: [2, 3]
{{ slice 1 }} // Error

has

The function checks if a specified element is present within a collection, returning true if the element is found.

Signature

Has(element any, list any) (bool, error)

Template Example

{{ [1, 2, 3, 4] | has 3 }} // Output: true, nil
{{ 3 | has 3 }} // Error

without

The function returns a new list that excludes the specified elements, effectively filtering out unwanted items from the original list.

Signature

Without(omit ...any, list any) ([]any, error)

Template Example

{{ [1, 2, 3, 4] | without 2, 4 }} // Output: [1, 3], nil
{{ without nil, nil }} // Error

rest

The function returns all elements of a list except for the first one, effectively giving you the "rest" of the list.

Signature

Rest(list any) ([]any, error)

Template Example

{{ [1, 2, 3, 4] | rest }} // Output: [2, 3, 4], nil
{{ rest 1 }} // Error

initial

The function returns all elements of a list except the last one, effectively providing the "initial" portion of the list.

Signature

Initial(list any) ([]any, error)

Template Example

{{ [1, 2, 3, 4] | initial }} // Output: [1, 2, 3]
{{ initial 1 }} // Error

first

The function returns the first element of a list.

Signature

First(list any) (any, error)

Template Example

{{ [1, 2, 3, 4] | first }} // Output: 1
{{ first nil }} // Error

last

The function returns the last element of a list.

Signature

Last(list any) (any, error)

Template Example

{{ [1, 2, 3, 4] | last }} // Output: 4
{{ last nil }} // Error

reverse

The function returns a new list with the elements in reverse order, flipping the sequence of the original list.

Signature

Reverse(list any) ([]any, error)

Template Example

{{ [1, 2, 3, 4] | reverse }} // Output: [4, 3, 2, 1]
{{ reverse nil }} // Error

sortAlpha

The function sorts a list of strings in alphabetical order.

Signature

SortAlpha(list any) []string

Template Example

{{ ["d", "b", "a", "c"] | sortAlpha }} // Output: ["a", "b", "c", "d"]
{{ [4, 3, 2, 1, "a"] | sortAlpha }} // Output: ["1", "2", "3", "4", "a"]

splitList

The function splits a string into a slice of substrings based on the specified separator.

This function may be renamed in the future to better reflect its purpose.

Signature

SplitList(sep string, str string) []string

Template Example

{{ "one, two, three" | splitList ", " }} // Output: ["one", "two", "three"]

strSlice

The function converts a given value into a slice of strings, handling various input types including []string, []any, and other slice types, ensuring flexible type conversion to a string slice.

Signature

StrSlice(value any) []string

Template Example

{{ strSlice ["a", "b", "c"] }} // Output: ["a", "b", "c"]
{{ strSlice [5, "a", true, nil, 1] }} // Output: ["5", "a", "true", "1"]

until

The function generates a slice of integers starting from 0 up to, but not including, the specified count. If count is negative, it produces a descending slice from 0 down to count, inclusive, stepping by -1. The function utilizes UntilStep to dynamically determine the range and step size.

Signature

Until(count int) []int

Template Example

{{ 5 | until }} // Output: [0 1 2 3 4]
{{ -3 | until }} // Output: [0 -1 -2]

untilStep

The function generates a slice of integers from start to stop (exclusive), incrementing by the specified step. If step is positive, the sequence ascends; if negative, it descends. The function returns an empty slice if the sequence is logically invalid, such as when a positive step is used but start is greater than stop, or vice versa.

Signature

UntilStep(start, stop, step int) []int

Template Example

{{ 0, 10, 2 | untilStep }} // Output: [0 2 4 6 8]
{{ 10, 0, -2 | untilStep }} // Output: [10 8 6 4 2]