dirstate-tree: Add tree traversal/iteration
Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.
Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.
This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.
Differential Revision: https://phab.mercurial-scm.org/D10370
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.SH NAME
chg \- a fast client for Mercurial command server
.SH SYNOPSIS
.B chg
.IR command " [" options "] [" arguments "]..."
.br
.SH DESCRIPTION
The
.B chg
command is the wrapper for
.B hg
command.
It uses the Mercurial command server to reduce start-up overhead.
.SH OPTIONS
This program accepts the same command line syntax as the
.B hg
command. Additionally it accepts the following options.
.TP
.B \-\-kill\-chg\-daemon
Terminate the background command servers.
.SH SEE ALSO
.BR hg (1)
.SH AUTHOR
Written by Yuya Nishihara <yuya@tcha.org>.