iters

package
v0.4.135 Latest Latest
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 Go to latest Published: Dec 3, 2023 License: ISC Imports: 7 Imported by: 2

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Constants

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Variables

This section is empty.

Functions

This section is empty.

Types

type BaseIterator added in v0.4.117 

type BaseIterator[T any] struct {
	// contains filtered or unexported fields
}

BaseIterator implements:

  • the DelegateAction[T] function required by Delegator[T]
  • Cond and Cancel methods part of iters.Iterator
  • consumer needs to implement Init method

func NewBaseIterator added in v0.4.117 

func NewBaseIterator[T any](iteratorAction IteratorAction[T]) (iterator *BaseIterator[T])

NewFunctionIterator returns a parli.Iterator based on a function. functionIterator is thread-safe and re-entrant.

func (BaseIterator) Cancel added in v0.4.117 

func (i BaseIterator) Cancel(errp ...*error) (err error)

Cancel stops an iteration

  • after Cancel invocation, Cond, Next and Same indicate no value available
  • Cancel returns the first error that occurred during iteration, if any
  • an iterator implementation may require Cancel invocation to release resources
  • Cancel is deferrable

func (BaseIterator) Cond added in v0.4.118 

func (i BaseIterator) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • condition is true if iterationVariable was assigned a value and the iteration should continue
  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution

Usage: 

for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
  // i is pointer to slice element

func (BaseIterator) Next added in v0.4.135 

func (i BaseIterator) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (BaseIterator) Same added in v0.4.135 

func (i BaseIterator) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type Converter added in v0.4.135 

type Converter[K any, V any] struct {

	// BaseIterator implements Cancel and the DelegateAction[T] function required by
	// Delegator[T]
	//	- receives invokeConverterFunction function
	//	- provides delegateAction function
	*BaseIterator[V]
	// contains filtered or unexported fields
}

Converter traverses another iterator and returns converted values

func (Converter) Cancel added in v0.4.135 

func (i Converter) Cancel(errp ...*error) (err error)

Cancel stops an iteration

  • after Cancel invocation, Cond, Next and Same indicate no value available
  • Cancel returns the first error that occurred during iteration, if any
  • an iterator implementation may require Cancel invocation to release resources
  • Cancel is deferrable

func (Converter) Cond added in v0.4.135 

func (i Converter) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • condition is true if iterationVariable was assigned a value and the iteration should continue
  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution

Usage: 

for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
  // i is pointer to slice element

func (*Converter[K, T]) Init added in v0.4.135 

func (i *Converter[K, T]) Init() (iterationVariable T, iterator Iterator[T])

Init implements the right-hand side of a short variable declaration in the init statement for a Go “for” clause

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (Converter) Next added in v0.4.135 

func (i Converter) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (Converter) Same added in v0.4.135 

func (i Converter) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type ConverterFunction added in v0.4.117 

type ConverterFunction[K any, V any] func(key K, isCancel bool) (value V, err error)

ConverterFunction is the signature used by NewConverterIterator

  • ConverterFunction receives a key and returns the corresponding value.
  • if isCancel true, it means this is the last invocation of ConverterFunction and ConverterFunction should release any resources. Any returned value is not used
  • ConverterFunction signals end of values by returning parl.ErrEndCallbacks. Any returned value is not used
  • if ConverterFunction returns error, it will not be invoked again. Any returned value is not used
  • ConverterFunction must be thread-safe
  • ConverterFunction is invoked by at most one thread at a time

type Empty added in v0.4.135 

type Empty[T any] struct{}

Empty is an iterator with no values. thread-safe.

func (*Empty[T]) Cancel added in v0.4.135 

func (i *Empty[T]) Cancel(errp ...*error) (err error)

func (*Empty[T]) Cond added in v0.4.135 

func (i *Empty[T]) Cond(iterationVariablep *T, errp ...*error) (condition bool)

func (*Empty[T]) Init added in v0.4.135 

func (i *Empty[T]) Init() (iterationVariable T, iterator Iterator[T])

func (*Empty[T]) Next added in v0.4.135 

func (i *Empty[T]) Next() (value T, hasValue bool)

func (*Empty[T]) Same added in v0.4.135 

func (i *Empty[T]) Same() (value T, hasValue bool)

type Function added in v0.4.135 

type Function[T any] struct {

	// BaseIterator implements the DelegateAction[T] function required by
	// Delegator[T] and Cancel
	//	- provides its delegateAction method to Delegator
	*BaseIterator[T]
	// contains filtered or unexported fields
}

Function traverses a function generating values

func (Function) Cancel added in v0.4.135 

func (i Function) Cancel(errp ...*error) (err error)

Cancel stops an iteration

  • after Cancel invocation, Cond, Next and Same indicate no value available
  • Cancel returns the first error that occurred during iteration, if any
  • an iterator implementation may require Cancel invocation to release resources
  • Cancel is deferrable

func (Function) Cond added in v0.4.135 

func (i Function) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • condition is true if iterationVariable was assigned a value and the iteration should continue
  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution

Usage: 

for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
  // i is pointer to slice element

func (*Function[T]) Init added in v0.4.135 

func (i *Function[T]) Init() (iterationVariable T, iterator Iterator[T])

Init implements the right-hand side of a short variable declaration in the init statement for a Go “for” clause

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (Function) Next added in v0.4.135 

func (i Function) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (Function) Same added in v0.4.135 

func (i Function) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type IntegerIterator added in v0.4.135 

type IntegerIterator[T constraints.Integer] struct {
	// contains filtered or unexported fields
}

func (*IntegerIterator[T]) Cancel added in v0.4.135 

func (i *IntegerIterator[T]) Cancel(errp ...*error) (err error)

Cancel stops an iteration

  • after Cancel invocation, Cond, Next and Same indicate no value available
  • Cancel returns the first error that occurred during iteration, if any
  • an iterator implementation may require Cancel invocation to release resources
  • Cancel is deferrable

func (*IntegerIterator[T]) Cond added in v0.4.135 

func (i *IntegerIterator[T]) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • condition is true if iterationVariable was assigned a value and the iteration should continue
  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution

Usage: 

for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
  // i is pointer to slice element

func (*IntegerIterator[T]) Init added in v0.4.135 

func (i *IntegerIterator[T]) Init() (iterationVariable T, iterator Iterator[T])

Init implements the right-hand side of a short variable declaration in the init statement of a Go “for” clause 

	for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*IntegerIterator[T]) Next added in v0.4.135 

func (i *IntegerIterator[T]) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (*IntegerIterator[T]) Same added in v0.4.135 

func (i *IntegerIterator[T]) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type Iterator 

type Iterator[T any] interface {
	// Init implements the right-hand side of a short variable declaration in
	// the init statement of a Go “for” clause
	//
	//		for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
	//	   // i is pointer to slice element
	Init() (iterationVariable T, iterator Iterator[T])
	// Cond implements the condition statement of a Go “for” clause
	//   - condition is true if iterationVariable was assigned a value and the iteration should continue
	//   - the iterationVariable is updated by being provided as a pointer.
	//     iterationVariable cannot be nil
	//   - errp is an optional error pointer receiving any errors during iterator execution
	//
	// Usage:
	//
	//  for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
	//    // i is pointer to slice element
	Cond(iterationVariablep *T, errp ...*error) (condition bool)
	// Next advances to next item and returns it
	//	- if hasValue true, value contains the next value
	//	- otherwise, no more items exist and value is the data type zero-value
	Next() (value T, hasValue bool)
	// Same returns the same value again
	//	- if hasValue true, value is valid
	//	- otherwise, no more items exist and value is the data type zero-value
	//	- If Next or Cond has not been invoked, Same first advances to the first item
	Same() (value T, hasValue bool)
	// Cancel stops an iteration
	//	- after Cancel invocation, Cond, Next and Same indicate no value available
	//	- Cancel returns the first error that occurred during iteration, if any
	//	- an iterator implementation may require Cancel invocation
	//		to release resources
	//	- Cancel is deferrable
	Cancel(errp ...*error) (err error)
}

Iterator allows traversal of values.

  • iterate over an unimported type using an iterator returning a derived value such as an interface type
  • convert a slice value-by-value, ie. return interface-type values from a struct slice
  • iterate over pointers to slice values
  • iterate over function
  • obtain errors occurring in the iterator or release iterator resources

The iterator interface is optimized for use in the Go “for” clause. Iterators in the iters package are thread-safe but thread-safety depends on iterator implementation.

Usage in Go “for” clause: 

for i, iterator := NewIterator().Init(); iterator.Cond(&i); {
  println(i)

var err error
for i, iterator := NewIterator().Init(); iterator.Cond(&i, &err); {
  println(i)
}
if err != nil {

var err error
var iterator = NewIterator()
for i := 0; iterator.Cond(&i); {
  println(i)
}
if err = iterator.Cancel(); err != nil {

func NewConverterIterator 

func NewConverterIterator[K any, V any](
	keyIterator Iterator[K],
	converter ConverterFunction[K, V],
) (iterator Iterator[V])

NewConverterIterator returns a converting iterator.

  • converterFunction receives cancel and can return error
  • ConverterIterator is thread-safe and re-entrant.
  • stores self-referencing pointers

func NewEmptyIterator 

func NewEmptyIterator[T any]() (iterator Iterator[T])

NewEmptyIterator returns an empty iterator of values type T.

  • EmptyIterator is thread-safe.

func NewFunctionIterator 

func NewFunctionIterator[T any](
	iteratorFunction IteratorFunction[T],
) (iterator Iterator[T])

NewFunctionIterator returns an Iterator iterating over a function

  • thread-safe

func NewIntegerIterator added in v0.4.135 

func NewIntegerIterator[T constraints.Integer](firstValue, lastValue T) (iterator Iterator[T])

func NewSimpleConverterIterator added in v0.4.135 

func NewSimpleConverterIterator[K any, V any](
	keyIterator Iterator[K],
	simpleConverter SimpleConverter[K, V],
) (iterator Iterator[V])

NewConverterIterator returns a converting iterator.

  • converterFunction receives cancel and can return error
  • ConverterIterator is thread-safe and re-entrant.
  • stores self-referencing pointers

func NewSimpleFunctionIterator added in v0.4.135 

func NewSimpleFunctionIterator[T any](
	iteratorFunction SimpleIteratorFunc[T],
) (iterator Iterator[T])

NewFunctionIterator returns an Iterator iterating over a function

  • thread-safe

func NewSliceInterfaceIterator added in v0.4.125 

func NewSliceInterfaceIterator[I any, E any](slice []E) (iterator Iterator[I])

NewSliceInterfaceIterator returns an iterator over slice []E returning those elements as interface I values

  • [I ~*E, E any] as an expression of interface I implemented by &E does not actually hold true at compile time. The check whether I is an interface implemented by &E has to take place at runtime
  • uses self-referencing pointers

func NewSliceIterator 

func NewSliceIterator[T any](slice []T) (iterator Iterator[T])

NewSliceIterator returns an iterator iterating over slice T values

  • thread-safe

func NewSlicePointerIterator added in v0.4.117 

func NewSlicePointerIterator[E any](slice []E) (iterator Iterator[*E])

NewSlicePointerIterator returns an iterator of pointers to T

  • the difference is that:
  • instead of copying a value from the slice,
  • a pointer to the slice value is returned
  • the returned Iterator value cannot be copied, the pointer value must be used
  • uses self-referencing pointers

func NewSlicePointerIteratorField added in v0.4.125 

func NewSlicePointerIteratorField[E any](fieldp *SlicePointer[E], slice []E) (iterator Iterator[*E])

type IteratorAction added in v0.4.135 

type IteratorAction[T any] func(isCancel bool) (
	value T,
	isPanic bool,
	err error,
)

IteratorAction is a delegated request from iters.BaseIterator

  • isCancel true requests cancel of iteration. No further invocations will occur. The iterator should release resources. The iterator may return an error
  • otherwise, the iterator can:
  • — return the next value
  • — return an error. No further invocations will occur
  • — return err == parl.ErrEndCallbacks requesting an end to iterations. No further invocations will occur ErrEndCallbacks error is not returned to the consumer
  • the returned value is used if:
  • — returned err is nil and
  • — provided isCancel was false and
  • — returned didCancel is false
  • isPanic indicates that err is the result of a panic. isPanic is only used if err is non-nil

type IteratorFunction added in v0.4.117 

type IteratorFunction[T any] func(isCancel bool) (value T, err error)

IteratorFunction is the signature used by NewFunctionIterator

  • if isCancel true, it means this is the last invocation of IteratorFunction and IteratorFunction should release any resources. Any returned value is not used
  • IteratorFunction signals end of values by returning parl.ErrEndCallbacks. Any returned value is not used
  • if IteratorFunction returns error, it will not be invoked again. Any returned value is not used
  • IteratorFunction must be thread-safe
  • IteratorFunction is invoked by at most one thread at a time

type NextAction 

type NextAction bool

NextAction is a unique named type that indicates whether the next or the same value again is sought by Delegate.Next

  • IsSame IsNext
const (
	// IsSame indicates to Delegate.Next that
	// this is a Same-type incovation
	IsSame NextAction = false
	// IsNext indicates to Delegate.Next that
	// this is a Next-type incovation
	IsNext NextAction = true
)

func (NextAction) String 

func (a NextAction) String() (s string)

type Simple added in v0.4.135 

type Simple[K any, V any] struct {

	// BaseIterator implements Cancel and the DelegateAction[T] function required by
	// Delegator[T]
	//	- receives invokeConverterFunction function
	//	- provides delegateAction function
	BaseIterator[V]
	// contains filtered or unexported fields
}

Converter traverses another iterator and returns converted values

func (Simple) Cancel added in v0.4.135 

func (i Simple) Cancel(errp ...*error) (err error)

Cancel stops an iteration

  • after Cancel invocation, Cond, Next and Same indicate no value available
  • Cancel returns the first error that occurred during iteration, if any
  • an iterator implementation may require Cancel invocation to release resources
  • Cancel is deferrable

func (Simple) Cond added in v0.4.135 

func (i Simple) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • condition is true if iterationVariable was assigned a value and the iteration should continue
  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution

Usage: 

for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
  // i is pointer to slice element

func (*Simple[K, T]) Init added in v0.4.135 

func (i *Simple[K, T]) Init() (iterationVariable T, iterator Iterator[T])

Init implements the right-hand side of a short variable declaration in the init statement for a Go “for” clause

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (Simple) Next added in v0.4.135 

func (i Simple) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (Simple) Same added in v0.4.135 

func (i Simple) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type SimpleConverter added in v0.4.135 

type SimpleConverter[K any, V any] func(key K) (value V)

type SimpleFunc added in v0.4.135 

type SimpleFunc[T any] struct {

	// BaseIterator implements the DelegateAction[T] function required by
	// Delegator[T] and Cancel
	//	- provides its delegateAction method to Delegator
	*BaseIterator[T]
	// contains filtered or unexported fields
}

Function traverses a function generating values

func (SimpleFunc) Cancel added in v0.4.135 

func (i SimpleFunc) Cancel(errp ...*error) (err error)

Cancel stops an iteration

  • after Cancel invocation, Cond, Next and Same indicate no value available
  • Cancel returns the first error that occurred during iteration, if any
  • an iterator implementation may require Cancel invocation to release resources
  • Cancel is deferrable

func (SimpleFunc) Cond added in v0.4.135 

func (i SimpleFunc) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • condition is true if iterationVariable was assigned a value and the iteration should continue
  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution

Usage: 

for i, iterator := iters.NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
  // i is pointer to slice element

func (*SimpleFunc[T]) Init added in v0.4.135 

func (i *SimpleFunc[T]) Init() (iterationVariable T, iterator Iterator[T])

Init implements the right-hand side of a short variable declaration in the init statement for a Go “for” clause

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (SimpleFunc) Next added in v0.4.135 

func (i SimpleFunc) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (SimpleFunc) Same added in v0.4.135 

func (i SimpleFunc) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type SimpleIteratorFunc added in v0.4.135 

type SimpleIteratorFunc[T any] func() (value T, hasValue bool)

type Slice added in v0.4.135 

type Slice[T any] struct {
	// contains filtered or unexported fields
}

Slice traverses a slice container. thread-safe

func (*Slice[T]) Cancel added in v0.4.135 

func (i *Slice[T]) Cancel(errp ...*error) (err error)

Cancel release resources for this iterator. Thread-safe

  • not every iterator requires a Cancel invocation

func (*Slice[T]) Cond added in v0.4.135 

func (i *Slice[T]) Cond(iterationVariablep *T, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution
  • condition is true if iterationVariable was assigned a value and the iteration should continue

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*Slice[T]) Init added in v0.4.135 

func (i *Slice[T]) Init() (iterationVariable T, iterator Iterator[T])

Init implements the right-hand side of a short variable declaration in the init statement for a Go “for” clause

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*Slice[T]) Next added in v0.4.135 

func (i *Slice[T]) Next() (value T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (*Slice[T]) Same added in v0.4.135 

func (i *Slice[T]) Same() (value T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type SliceInterface added in v0.4.135 

type SliceInterface[I any, E any] struct {
	SlicePointer[E]
}

func (*SliceInterface[I, E]) Cond added in v0.4.135 

func (i *SliceInterface[I, E]) Cond(iterationVariablep *I, errp ...*error) (condition bool)

Cond updates I interface pointers

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*SliceInterface[I, E]) Init added in v0.4.135 

func (i *SliceInterface[I, E]) Init() (iterationVariable I, iterator Iterator[I])

Init initializes I interface values and returns an I iterator

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*SliceInterface[I, E]) Next added in v0.4.135 

func (i *SliceInterface[I, E]) Next() (value I, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (*SliceInterface[I, E]) Same added in v0.4.135 

func (i *SliceInterface[I, E]) Same() (value I, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

type SlicePointer added in v0.4.135 

type SlicePointer[E any] struct {
	// contains filtered or unexported fields
}

SlicePointer traverses a slice container using pointers to value. thread-safe.

  • the difference is that:
  • instead of copying a value from the slice,
  • a pointer to the slice value is returned

func (*SlicePointer[E]) Cancel added in v0.4.135 

func (i *SlicePointer[E]) Cancel(errp ...*error) (err error)

Cancel release resources for this iterator. Thread-safe

  • not every iterator requires a Cancel invocation

func (*SlicePointer[E]) Cond added in v0.4.135 

func (i *SlicePointer[E]) Cond(iterationVariablep **E, errp ...*error) (condition bool)

Cond implements the condition statement of a Go “for” clause

  • the iterationVariable is updated by being provided as a pointer. iterationVariable cannot be nil
  • errp is an optional error pointer receiving any errors during iterator execution
  • condition is true if iterationVariable was assigned a value and the iteration should continue

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*SlicePointer[E]) Init added in v0.4.135 

func (i *SlicePointer[E]) Init() (iterationVariable *E, iterator Iterator[*E])

Init implements the right-hand side of a short variable declaration in the init statement for a Go “for” clause

Usage: 

	for i, iterator := NewSlicePointerIterator(someSlice).Init(); iterator.Cond(&i); {
   // i is pointer to slice element

func (*SlicePointer[T]) Next added in v0.4.135 

func (i *SlicePointer[T]) Next() (value *T, hasValue bool)

Next advances to next item and returns it

  • if hasValue true, value contains the next value
  • otherwise, no more items exist and value is the data type zero-value

func (*SlicePointer[T]) Same added in v0.4.135 

func (i *SlicePointer[T]) Same() (value *T, hasValue bool)

Same returns the same value again

  • if hasValue true, value is valid
  • otherwise, no more items exist and value is the data type zero-value
  • If Next or Cond has not been invoked, Same first advances to the first item

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