63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
package commands
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type cmdHistory struct {
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// rolling buffer of prior commands
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//
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// most recent command is at the end of the list,
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// least recent is index 0
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cmdList []string
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// current placement in list
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current int
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}
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// number of commands to keep in history
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const cmdLimit = 1000
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// CmdHistory is the history of executed commands
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var CmdHistory = cmdHistory{}
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func (h *cmdHistory) Add(cmd string) {
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// if we're at cap, cut off the first element
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if len(h.cmdList) >= cmdLimit {
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h.cmdList = h.cmdList[1:]
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}
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h.cmdList = append(h.cmdList, cmd)
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// whenever we add a new command, reset the current
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// pointer to the "beginning" of the list
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h.Reset()
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}
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// Prev returns the previous command in history.
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// Since the list is reverse-order, this will return elements
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// increasingly towards index 0.
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func (h *cmdHistory) Prev() string {
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if h.current <= 0 || len(h.cmdList) == 0 {
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h.current = -1
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return "(Already at beginning)"
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}
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h.current--
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return h.cmdList[h.current]
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}
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// Next returns the next command in history.
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// Since the list is reverse-order, this will return elements
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// increasingly towards index len(cmdList).
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func (h *cmdHistory) Next() string {
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if h.current >= len(h.cmdList)-1 || len(h.cmdList) == 0 {
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h.current = len(h.cmdList)
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return "(Already at end)"
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}
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h.current++
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return h.cmdList[h.current]
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}
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// Reset the current pointer to the beginning of history.
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func (h *cmdHistory) Reset() {
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h.current = len(h.cmdList)
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}
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