# Eachable1 type

## Direct parent types

- Eachable
Parent type of all types that have each() method Direct subtypes: 2

## Direct children types

- Arr
Array - ordered list of items accessed by zero-based index

- ArrIter
Arr (array) iterator.

- ArrLike
Parent type for user-defined types with array-like behaviour. Use in cases when you would like to inherit from built-in Arr. Inheriting from built-ins is not possible for now. Direct subtypes: 3

- Box
A box which might (FullBox) or might not (EmptyBox) contain a value. Box is somewhat similar to Arr of zero (EmptyBox) or exactly one (FullBox) element. This analogy helps understanding each() and filter() operation. Direct subtypes: 2

- ConstIter
Iterator that returns given value forever.

- FilterIter
EXPERIMENTAL! Do not use!

- FunIter
EXPERIMENTAL! Do not use!

- Int
Integer type. On 64 bit platforms it's a 61 bit signed integer

- MapIter
EXPERIMENTAL! Do not use!

- MultiMethod
MultiMethod, container for methods.

- NumRange
Numerical range

- RangeIter
Iterates over a Range

- ResDef
Abstract resource definition Direct subtypes: 2

- Set
Represents a set of items

- Str
String type. Contains sequential bytes.

- Table
Holds tabular data

## Methods

- +(a:Eachable1, b:Eachable1) Source: stdlib.ngs:650
Undocumented

- +(s:Str, a:Eachable1) Source: stdlib.ngs:3603
Prepend each line in a with s #### Returns

Type of ret is same as type of a#### Example

"a " + ["1", "2"] # ["a 1", "a 2"]

- +(a:Eachable1, s:Str) Source: stdlib.ngs:3613
Append s to each line in a #### Returns

Type of ret is same as type of a#### Example

["1", "2"] + " a" # ["1 a", "2 a"]

- any(e:Eachable1, predicate:Any) Source: stdlib.ngs:1683
Check whether there is any element in e that satisfies the given predicate. #### Parameters

e The items to check predicate Test function #### Returns

Bool#### Example

[1,2,10].any(F(elt) elt > 5) # true [1,2,10].any(F(elt) elt > 15) # false

- Arr(something:Eachable1) Source: stdlib.ngs:2021
Convert Eachable1 (anything with "each" method that takes callback of one parameter) to an array #### Example

Arr(1..3) # [1,2] Arr(1...3) # [1,2,3]

- count(e:Eachable1, predicate:Any) Source: stdlib.ngs:1863
Count number of items that satisfy the predicate. #### Parameters

e Items to look at predicate Test function #### Returns

Int#### Example

[1,2,3,11,12].count(X>10) # 2

- dflt(e:Eachable1, k:Any, v:Any) Source: stdlib.ngs:1066
Set a field on all elements if it's not already set #### Parameters

e Eachable1 with elements of type NormalTypeInstance or Hash #### Returns

e#### Example

my_items.dflt("source", "(unknown)")

- drop(e:Eachable1, predicate:Any)experimental Source: stdlib.ngs:506
EXPERIMENTAL! Do not use! Filters out items that satisfy predicate at the begginning of e. #### Example

[1,2,3,1,2].drop(X<3) # [3,1,2]

- each_chunk(e:Eachable1, n:Int, cb:Fun)experimental Source: stdlib.ngs:2333
Call cb with array of maximum length of n, repeatedely for all items of e. TODO: better doc

- each_idx_val(e:Eachable1, cb:Fun) Source: stdlib.ngs:1757
Iterates over elements of e, passing each in turn to cb along with index and args: cb(INDEX, ITEM) #### Returns

e#### Example

"abc".each_idx_val(F(idx, val) echo("Element #$idx equals to $val"))

- filter(e:Eachable1, predicate:Any) Source: stdlib.ngs:324
Filter e using predicate. #### Parameters

e Eachable1. WARNING: instances of same type as e must have empty constructor and push() method. predicate Decision function to be called with each item as first argument. When predicate(item) returns true, the item will appear in the resulting array. #### Returns

Of same type as e#### Example

(1...10).filter(F(num) num % 2 == 0) # Gives [2,4,6,8,10] (1...10).filter(X<5) # Gives [1,2,3,4], predicate called as predicate(item, 5)

- filter(something:Eachable1, field:Str, predicate:Any)deprecated Source: stdlib.ngs:339
DEPRECATED! Do not use! Use something.filter({field: predicate}) instead.

- filter(e:Eachable1)deprecated Source: stdlib.ngs:464
Filter nulls out. DEPRECATED, USE something.without(null) INSTEAD. #### Returns

Arr (array) of original items without nulls

- first(e:Eachable1, predicate:Any, default:Any) Source: stdlib.ngs:368
Find first element in e that satisfies the predicate. #### Returns

Either the element or the provided default if element was not found.#### Example

(10..20).first(F(x) x % 3 == 0) # 12 - first item divisible by 3 (10..20).first(F(x) x % 50 == 0, 1000) # 1000

- first(e:Eachable1, predicate:Any) Source: stdlib.ngs:384
Find first element in e that satisfies the predicate. Throws ElementNotFound exception if no such element is found. #### Returns

The element.#### Example

(10..20).first(F(x) x % 3 == 0) # 12 - first item divisible by 3 (10..20).first(F(x) x % 50 == 0) # ElementNotFound exception

- first(e:Eachable1) Source: stdlib.ngs:399
Find first element in e that satisfies Bool(e) == true. Exactly same as first(e, identity). #### Example

[false, 0, null, "xyz", 100].first() # "xyz" [].first() # ElementNotFound exception

- flatten(e:Eachable1) Source: stdlib.ngs:1886
Flatten one level. #### Parameters

e Eachable with each element also Eachable #### Returns

Arr#### Example

[[1], [2,3]].flatten() # [1,2,3]

- get(e:Eachable1, field:Str) Source: stdlib.ngs:1600
Return array made of given field of each element of given Eachable1 where present #### Returns

Arr#### Example

[{"x": 1}, {"y": 2}].get("x") # [1] ``aws ec2 describe-instances``.Tags.get("role").uniq() # Returns Arr of Str with roles. Does not crash if some machines do not have "role" tag.

- get(e:Eachable1, field:Str, dflt:Any) Source: stdlib.ngs:1608
Return array made of given field of each element of given Eachable1 where present or default value where the field is not present. #### Returns

Arr#### Example

[{"x": 1}, {"y": 2}].get("x", null) # [1, null]

- group(e:Eachable1, cb:Fun) Source: stdlib.ngs:2732
Group items from e by key returned by cb #### Returns

Hash with Arr values#### Example

["ab", "ac", "ba", "bc", "bd"].group(F(x) x[0]) # {a=[ab,ac], b=[ba,bc,bd]}

- Hash(e:Eachable1, key_field:Str, val_field:Str) Source: stdlib.ngs:2674
Create Hash from Arr of something that has key and value fields #### Parameters

e Eachable1 with all the keys and values key_field Name of the field holding the keys of newly created Hash val_field Name of the field holding the values of newly created Hash #### Returns

Hash#### Example

Hash([{"Name": "n1", "Value": "v1"},{"Name": "n2", "Value": "v2"}], "Name", "Value") # {"n1": "v1", "n2": "v2"}

- in(x:Any, e:Eachable1) Source: stdlib.ngs:632
Checks whether element x is in Eachable1 #### Parameters

x Needle e Haystack #### Returns

Bool#### Example

1 in [1,2,3].Iter() # true 10 in [1,2,3].Iter() # false

- indexes(e:Eachable1, predicate:Any) Source: stdlib.ngs:1936
Find all indexes of values that satisfy the predicate #### Parameters

predicate Test function #### Returns

Arr of Int#### Example

[1,5,1,10].indexes(X>2) # [1,3]

- init(s:Set, e:Eachable1) Source: autoload/Set.ngs:12
Convert array to set

- map_idx_val(e:Eachable1, mapper:Fun) Source: stdlib.ngs:1779
Map an Eachable1 to an Arr (array) of values using mapper mapper is called as mapper(INDEX, ITEM) #### Returns

New Arr#### Example

echo("Array items: " + ArrLike().push(10).push(20).push(30).map_idx_val(F(idx, val) "[$idx]=$val").join(", ")) # Outputs: Array items: [0]=10, [1]=20, [2]=30

- mapo(e:Eachable1, mapper:Fun)experimental Source: stdlib.ngs:290
EXPERIMENTAL! Do not use! Map e to same type. Mnemonics: "map original" / "MAP to Original type". #### Parameters

e object of any type that has each(e, callback) implemented Eachable1. WARNING: instances of same type as e must have empty constructor and push() method. #### Returns

Of same type as e#### Example

Set([1,2]).mapo(X*2) # Set([2,4])

- max(e:Eachable1) Source: stdlib.ngs:2191
Find maximal element under (>)

- max(e:Eachable1, cb:Fun)deprecated Source: stdlib.ngs:2208
EXPERIMENTAL! Do not use!

- min(e:Eachable1) Source: stdlib.ngs:2189
Find minimal element under (<)

- min(e:Eachable1, cb:Fun)deprecated Source: stdlib.ngs:2202
EXPERIMENTAL! Do not use!

- none(e:Eachable1, predicate:Fun) Source: stdlib.ngs:1718
Check that there is no element in e that satisfies the given predicate. Exactly same as not(any(e, predicate)) . #### Returns

Bool#### Example

[0,1,2].none(X>2) # true [0,1,2].none(X<2) # false

- partition(something:Eachable1, predicate:Any) Source: stdlib.ngs:350
Partition elements in something according to the predicate into two arrays. First array contains all elements for which predicate(elt) is true and the second array contains all elements for which predicate(elt) is false. #### Parameters

something Eachable1 #### Returns

Array with two arrays in it#### Example

partition([1,10,2,20], X>=10) # [[10, 20], [1, 2]]

- pmap(e:Eachable1, mapper:Fun) Source: stdlib.ngs:3901
Parallel map. Runs mapper in threads. Each thread processes one element from the array but this might change in future (preserving the total number of calls to mapper and the order of results). #### Returns

Arr, result of applying mapper to elements of e, preserving the order.#### Example

pages_texts = abs_pages_urls.pmap(F(url) `lynx -dump $url`)

- push_all(dst:Any, e:Eachable1) Source: stdlib.ngs:640
Push all elements of e into dst. #### Returns

dst

- reduce(something:Eachable1, start:Any, f:Fun) Source: stdlib.ngs:538
Combine items to a single value using the supplied binary function First f is applied to start and the first element of something then on each step f is applied to previous result and next element of something. #### Parameters

something object of any type that has each(something, callback) implemented start First argument of f, for the first call of f f The combining function #### Example

F sum(something) something.reduce(0, (+))

- reduce(e:Eachable1, f:Fun) Source: stdlib.ngs:559
Combine items to a single value using the supplied binary function First f is applied to the first two elements of e then on each step f is applied to previous result and next element of e. Throws EmptyEachableFail if e has no elements. If e has only one element, that element is returned. #### Parameters

e object of any type that has each(e, callback) implemented f The combining function #### Example

F sum(e) e.reduce((+))

- replace(something:Eachable1, src:Any, dst:Any) Source: stdlib.ngs:525
Replace all occurrences of src with dst TODO: Return same type, not Arr #### Parameters

something object of any type that has each(something, callback) implemented #### Returns

Arr#### Example

["ssh", "IP", "w"].replace("IP", "10.0.0.100") # ['ssh','10.0.0.100','w']

- split(e:Eachable1, delim:Any) Source: stdlib.ngs:2313
Split e into arrays #### Returns

Arr of Arr#### Example

[1, "a", 2, 3, "a", 4].split("a") # [[1], [2, 3], [4]]

- sum(something:Eachable1) Source: stdlib.ngs:1964
Calculate sum of the elements #### Example

[1,2,3].sum() # 6

- take(something:Eachable1, predicate:Any)experimental Source: stdlib.ngs:487
EXPERIMENTAL! Do not use! #### Example

[1,2,3,1,2].take(X<3) # [1,2]

- the_one(e:Eachable1, predicate:Any) Source: stdlib.ngs:405
Find the only element that satisfies the predicate. Throws ElementNotFound exception if there are no elements that satisfy the predicate or if there is more than one element that satisfies the predicate. #### Returns

The only element that satisfies the predicate.

- the_one(e:Eachable1, predicate:Any, body:Fun, found_more:Fun=method, found_none:Fun=method) Source: stdlib.ngs:430
Find the only element that satisfies the predicate and execute given code with the value #### Parameters

body The code to execute when exactly one element that satisfies the predicate was found. Executed with the found value. It's value will be returned as result of the_one(). found_more The code to execute when more than one element satisfies the predicate. It's value will be returned as result of the_one(). Defaults to function returning null. found_none The code to execute when none of the elements satisfy the predicate. It's value will be returned as result of the_one(). Defaults to function returning null. #### Returns

Result of running on of the following: body, found_more, found_none#### Example

F name(dn:MethodDocNode) { dn.children.the_one(MethodNameDocNode).text[0] }

- the_one(e:Eachable1) Source: stdlib.ngs:456
Extract the only element. Throws ElementNotFound exception if there are no elements or if there is more than one element. #### Returns

The only element.#### Example

``aws ec2 describe-security-groups --group-ids $sg_id``.the_one() # {OwnerId=..., VpcId=..., GroupId=..., ...}

- without(e:Eachable1, without_elt:Any) Source: stdlib.ngs:1837
Filter out all occurrences of specific value #### Parameters

e items to filter without_elt The value to filter out #### Returns

Arr#### Example

[1,2,3,2].without(2) # [1,3]