Associations »

Association ( <|…|> ) — an association between keys and values

Key — indicate a key within a part specification

Keys  ▪  Values  ▪  Lookup  ▪  KeySort  ▪  KeyUnion

Merge — combine elements that have common keys

Counts, CountsBy — associate values with the number of times they occur

GroupBy — group values by collecting those sharing a criterion ("map reduce")

JoinAcross — combine lists of associations that match ("SQL join")

PositionIndex — build an index of positions at which values occur

Templates »

StringTemplate  ▪  FileTemplate  ▪  XMLTemplate  ▪  NotebookTemplate

TemplateObject — general symbolic template

TemplateExpression — an arbitrary expression evaluated when the template is applied

TemplateApply  ▪  TemplateSequence  ▪  TemplateSlot  ▪  TemplateIf  ▪  TemplateWith  ▪  ...

Entities »

EntityValue — get values for properties of entities

Entity — represent a particular entity in the world

EntityProperty  ▪  EntityProperties  ▪  CommonName  ▪  CanonicalName  ▪  EntityTypeName  ▪  ...

Finding Elements »

SelectFirst, FirstCase, FirstPosition — find the first element satisfying a criterion

MaximalBy, MinimalBy — find elements that maximize, minimize a criterion

Testing Expressions »

AllTrue, AnyTrue, NoneTrue — apply a test multiple times across a list

IntersectingQ, DisjointQ, SubsetQ — compare elements of two sets

BooleanQ