# vim:se syntax=tcl:

source [file dirname [info script]]/testing.tcl

needs cmd tailcall
needs cmd try tclcompat

test tailcall-1.1 {Basic tailcall} {
	# Demo -- a tail-recursive factorial function
	proc fac {x {val 1}} {
		if {$x <= 2} {
			expr {$x * $val}
		} else {
			tailcall fac [expr {$x -1}] [expr {$x * $val}]
		}
	}
	fac 10
} {3628800}

test tailcall-1.2 {Tailcall in try} {
	set x 0
	proc a {} { upvar x x; incr x }
	proc b {} { upvar x x; incr x 4; try { tailcall a } finally { incr x 8 }}
	b
	set x
} {13}

test tailcall-1.3 {Tailcall does return} {
	set x 0
	proc a {} { upvar x x; incr x }
	proc b {} { upvar x x; incr x 4; tailcall a; incr x 8}
	b
	set x
} {5}

test tailcall-1.5 {interaction of uplevel and tailcall} {
	proc a {cmd} {
		tailcall $cmd
	}
	proc b {} {
		lappend result [uplevel 1 a c]
		lappend result [uplevel 1 a c]
	}
	proc c {} {
		return c
	}
	a b
} {c c}

test tailcall-1.6 {tailcall pass through return} {
	proc a {script} {
		# return from $script should pass through back to the caller
		tailcall foreach i {1 2 3} $script
	}
	proc b {} {
		a {return ok}
		# Should not get here
		return bad
	}
	b
} {ok}

test tailcall-1.7 {tailcall with namespaces} jim {
	proc a::b {} {
		proc c {} {
			return 1
		}
		set d [local lambda {} { c }]
		# $d should resolve in namespace 'a', not ""
		tailcall $d
	}
	a::b
} 1

test tailcall-1.8 {tailcall with local} jim {
	proc a {} {
		tailcall [local proc b {} { return c }]
	}
	a
} {c}

test tailcall-1.9 {tailcall with large number of invocations} {
	proc a {n} {
		if {$n == 0} {
			return 1
		}
		incr n -1
		tailcall a $n
	}
	a 1000
} 1

test tailcall-1.10 {tailcall through uplevel} {
	proc a {} { tailcall b }
	proc b {} { uplevel 1 c }
	proc c {} { tailcall d }
	proc d {} { return [info level] }
	a
} 1

test tailcall-1.11 {chained tailcall} {
	proc a {} { b }
	proc b {} { tailcall tailcall c }
	proc c {} { return [info level] }
	a
} 1

test tailcall-1.12 {uplevel tailcall} {
	proc a {} { b }
	proc b {} { uplevel 1 tailcall c }
	proc c {} { return [info level] }
	a
} 1

testreport
