Collection Class Operators 

List operators 

lhs LIST_:: rhs              // ::
lhs LIST_::: rhs             // :::
lhs SEQ_++ rhs               // ++
lhs SEQ_/: rhs               // /:
lhs SEQ_:\ rhs               // :\

Collection operators 

When the right-hand side expression is an anonymous function block or a case sequence function, the collection operators form an infix application tree. Otherwise, they form a selection or an application tree:

REF("list") MAP LAMBDA(PARAM("x")) ==> BLOCK(
  REF("x") INT_+ LIT(1)
)

REF("list") MAP (WILDCARD INT_+ LIT(1))

These print as:

list map { x =>
  x + 1
}

foo.map(_ + 1)

Here are the operators:

lhs FOREACH rhs              // foreach
lhs MAP rhs                  // map
lhs FLATMAP rhs              // flatMap
lhs COLLECT rhs              // collect
lhs FIND rhs                 // find
lhs SLICE (from, to)         // slice
lhs TAKE rhs                 // take
lhs DROP rhs                 // drop
lhs TAKEWHILE rhs            // take
lhs DROPWHILE rhs            // drop
lhs FILTER rhs               // filter
lhs WITHFILTER rhs           // withFilter
lhs FILTERNOT rhs            // filterNot
lhs SPLITAT rhs              // splitAt
lhs SPAN rhs                 // span
lhs PARTITION rhs            // partition
lhs GROUPBY rhs              // groupBy
lhs FORALL rhs               // forall
lhs EXISTS rhs               // exists
lhs COUNT rhs                // count
lhs FOLDLEFT rhs             // foldLeft
lhs FOLDRIGHT rhs            // foldRight
lhs REDUCELEFT rhs           // reduceLeft
lhs REDUCERIGHT rhs          // reduceRight

Collection Constructors 

Here are built-in constructors and values:

LIST(arg, ...)               // List
NIL                          // Nil
pat1 UNLIST_:: pat2          // ::
SOME(arg, ...)               // Some
NONE                         // None
RIGHT(arg)                   // Right
LEFT(arg)                    // Left
ARRAY(arg, ...)              // Array
SEQ(arg, ...)                // Seq
VECTOR(arg, ...)             // Vector
MAKE_MAP(k ANY_-> v, ...)    // Map