Option -- the class of all pairs x => y

i1 : a => 5

o1 = a => 5

o1 : Option

i2 : peek (a => 5)

o2 = Option{a, 5}

i3 : new HashTable from {a => 5, b => 7}

o3 = HashTable{a => 5}
               b => 7

o3 : HashTable

Functions and methods returning an option :

• Thing => Thing, see => -- produce an Option

Methods that use an option :

• directSum(Option), see directSum -- direct sum of modules or maps
• Option ++ Option, see directSum -- direct sum of modules or maps
• installAssignmentMethod(Symbol,HashTable,HashTable,Option), see installAssignmentMethod -- install methods assignment to the value of an operator
• installAssignmentMethod(Symbol,HashTable,Option), see installAssignmentMethod -- install methods assignment to the value of an operator
• Option ? Option (missing documentation)
• substitute(Ideal,Option), see substitute -- substituting values for variables
• substitute(Matrix,Option), see substitute -- substituting values for variables
• substitute(Module,Option), see substitute -- substituting values for variables
• substitute(RingElement,Option), see substitute -- substituting values for variables
• substitute(Vector,Option), see substitute -- substituting values for variables

For the programmer

The object Option is a type, with ancestor classes BasicList < Thing.