53 lines
981 B
Go
53 lines
981 B
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// iterator.go
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package kern
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import (
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// "errors"
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"fmt"
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)
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// Operator names
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const (
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InitName = "init"
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CleanName = "clean"
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ResetName = "reset"
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NextName = "next"
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CurrentName = "current"
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IndexName = "index"
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CountName = "count"
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FilterName = "filter"
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MapName = "map"
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KeyName = "key"
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ValueName = "value"
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)
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type Iterator interface {
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Typer
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fmt.Stringer
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Next() (item any, err error) // must return io.EOF after the last item
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Current() (item any, err error)
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Index() int64
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Count() int64
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HasOperation(name string) bool
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CallOperation(name string, args map[string]any) (value any, err error)
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}
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type ExtIterator interface {
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Iterator
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Reset() error
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Clean() error
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}
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func ErrNoOperation(name string) error {
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return fmt.Errorf("no %s() function defined in the data-source", name)
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}
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func IsIterator(v any) (ok bool) {
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_, ok = v.(Iterator)
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return
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}
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