Pooh program example 03-stack.p
Test 03-stack.p
Source of programm
# test stack data structure - stack.inc
include 'stack.inc'
println( ~msg 'stack of numbers' )
l = make_stack()
l . push( ~data 1 )
l . push( ~data 2 )
l . push( ~data 3 )
l . push( ~data 4 )
while l . count() != 0
r = l . pop( )
println( ~msg r )
end
println( ~msg 'stack of arrays' )
l . push( ~data [ 1, 2] )
l . push( ~data [ 2, 3] )
l . push( ~data [ 3, 4] )
l . push( ~data [ 5, 6] )
while l . count() != 0
r = l . pop( )
println( ~msg join( ~array r ~separator ' - ' ) )
end
print( ~msg '*** eof stack test ***' )
Included file: stack.inc
sub make_stack_node( data optional )
# this ugly construct forces to return a node in heap memory.
# i think the notion of a clear language has to be revised a bit ;-)
l = [ [ Null, data ] ]
return l[1]
end
# constructs a linked list stack
sub make_stack()
e := make_stack_node( )
return {
'head' : e,
'ncount' : 0,
# add new element to the top of the stack
'push' : sub( data )
newnode := make_stack_node( ~data data )
if defined( ~arg this . head[ 1 ] )
newnode[ 1 ] := this . head [ 1 ]
end
this . head[ 1 ] := newnode
this . ncount = this . ncount + 1
#dump( ~arg this . head )
#println( ~msg '***' )
end,
# removes an element from the stack; the last value inserted with push is the first one returned by pop.
'pop' : sub( )
if ! defined( ~arg this . head[ 1 ] )
return Null
end
rt := this . head[ 1 ]
this . head[ 1 ] := rt[ 1 ]
this . ncount = this . ncount - 1
#dump( ~arg this . head )
#println( ~msg '***' )
return rt[ 2 ]
end,
'count' : sub()
return this . ncount
end
}
end
Standard output for 03-stack.p
stack of numbers
4
3
2
1
stack of arrays
5 - 6
3 - 4
2 - 3
1 - 2
*** eof stack test ***
Trace output for 03-stack.p
003|println( ~msg 'stack of numbers' )...
005|... = make_stack( )...
012| ... := make_stack_node( )...
006| l = [ [ Null , data:Null] ]
007| return l[1]:[ -> Null, -> Null ]
012| e := make_stack_node( ):-> [ -> Null, -> Null ]
013| return { 'head' : e:-> [ -> Null, -> Null ] , 'ncount' : 0 , 'push' : sub (~data) , 'pop' : sub () , 'count' : sub () }
005|l = make_stack( ):{ 'count' : sub , 'head' : -> [ -> Null, -> Null ], 'pop' : sub , 'ncount' : -> 0, 'push' : sub }
007|l{'push'}:sub ( ~data 1 )...
019| ... := make_stack_node( ~data data:1 )...
006| l = [ [ Null , data:1] ]
007| return l[1]:[ -> Null, -> 1 ]
019| newnode := make_stack_node( ~data data:1 ):-> [ -> Null, -> 1 ]
020| if defined( ~arg this{'head'}[1]:Null )...
020| if defined( ~arg this{'head'}[1]:Null ):0
021| end # if
023| this{'head'}[1]:[ -> Null, -> 1 ] := newnode:-> [ -> Null, -> 1 ]
024| this{'ncount'}:1 = (this{'ncount'}:0 + 1):1
008|l{'push'}:sub ( ~data 2 )...
019| ... := make_stack_node( ~data data:2 )...
006| l = [ [ Null , data:2] ]
007| return l[1]:[ -> Null, -> 2 ]
019| newnode := make_stack_node( ~data data:2 ):-> [ -> Null, -> 2 ]
020| if defined( ~arg this{'head'}[1]:[ -> Null, -> 1 ] )...
020| if defined( ~arg this{'head'}[1]:[ -> Null, -> 1 ] ):1
021| newnode[1]:[ -> Null, -> 1 ] := this{'head'}[1]:[ -> Null, -> 1 ]
021| end # if
023| this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ] := newnode:-> [ -> [ -> Null, -> 1 ], -> 2 ]
024| this{'ncount'}:2 = (this{'ncount'}:1 + 1):2
009|l{'push'}:sub ( ~data 3 )...
019| ... := make_stack_node( ~data data:3 )...
006| l = [ [ Null , data:3] ]
007| return l[1]:[ -> Null, -> 3 ]
019| newnode := make_stack_node( ~data data:3 ):-> [ -> Null, -> 3 ]
020| if defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ] )...
020| if defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ] ):1
021| newnode[1]:[ -> [ -> Null, -> 1 ], -> 2 ] := this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ]
021| end # if
023| this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] := newnode:-> [ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ]
024| this{'ncount'}:3 = (this{'ncount'}:2 + 1):3
010|l{'push'}:sub ( ~data 4 )...
019| ... := make_stack_node( ~data data:4 )...
006| l = [ [ Null , data:4] ]
007| return l[1]:[ -> Null, -> 4 ]
019| newnode := make_stack_node( ~data data:4 ):-> [ -> Null, -> 4 ]
020| if defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] )...
020| if defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] ):1
021| newnode[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] := this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ]
021| end # if
023| this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ], -> 4 ] := newnode:-> [ -> [ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ], -> 4 ]
024| this{'ncount'}:4 = (this{'ncount'}:3 + 1):4
013|while (l{'count'}:sub ( )...
046| return this{'ncount'}:4
013|while (l{'count'}:sub ( ):-> 4 != 0):true
014| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ], -> 4 ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ], -> 4 ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ], -> 4 ]
036| this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] := rt[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ]
037| this{'ncount'}:3 = (this{'ncount'}:4 - 1):3
042| return rt[2]:4
014| r = l{'pop'}:sub ( ):-> 4
015| println( ~msg r:4 )...
016|end
013|while (l{'count'}:sub ( )...
046| return this{'ncount'}:3
013|while (l{'count'}:sub ( ):-> 3 != 0):true
014| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> [ -> [ -> Null, -> 1 ], -> 2 ], -> 3 ]
036| this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ] := rt[1]:[ -> [ -> Null, -> 1 ], -> 2 ]
037| this{'ncount'}:2 = (this{'ncount'}:3 - 1):2
042| return rt[2]:3
014| r = l{'pop'}:sub ( ):-> 3
015| println( ~msg r:3 )...
016|end
013|while (l{'count'}:sub ( )...
046| return this{'ncount'}:2
013|while (l{'count'}:sub ( ):-> 2 != 0):true
014| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> [ -> Null, -> 1 ], -> 2 ]
036| this{'head'}[1]:[ -> Null, -> 1 ] := rt[1]:[ -> Null, -> 1 ]
037| this{'ncount'}:1 = (this{'ncount'}:2 - 1):1
042| return rt[2]:2
014| r = l{'pop'}:sub ( ):-> 2
015| println( ~msg r:2 )...
016|end
013|while (l{'count'}:sub ( )...
046| return this{'ncount'}:1
013|while (l{'count'}:sub ( ):-> 1 != 0):true
014| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> Null, -> 1 ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> Null, -> 1 ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> Null, -> 1 ]
036| this{'head'}[1]:Null := rt[1]:Null
037| this{'ncount'}:0 = (this{'ncount'}:1 - 1):0
042| return rt[2]:1
014| r = l{'pop'}:sub ( ):-> 1
015| println( ~msg r:1 )...
016|end
013|while (l{'count'}:sub ( )...
046| return this{'ncount'}:0
013|while (l{'count'}:sub ( ):-> 0 != 0):false
016|end # finish loop
018|println( ~msg 'stack of arrays' )...
020|l{'push'}:sub ( ~data [ 1 , 2] )...
019| ... := make_stack_node( ~data data:[ -> 1, -> 2 ] )...
006| l = [ [ Null , data:-> [ -> 1, -> 2 ]] ]
007| return l[1]:[ -> Null, -> [ -> 1, -> 2 ] ]
019| newnode := make_stack_node( ~data data:[ -> 1, -> 2 ] ):-> [ -> Null, -> [ -> 1, -> 2 ] ]
020| if defined( ~arg this{'head'}[1]:Null )...
020| if defined( ~arg this{'head'}[1]:Null ):0
021| end # if
023| this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ] := newnode:-> [ -> Null, -> [ -> 1, -> 2 ] ]
024| this{'ncount'}:1 = (this{'ncount'}:0 + 1):1
021|l{'push'}:sub ( ~data [ 2 , 3] )...
019| ... := make_stack_node( ~data data:[ -> 2, -> 3 ] )...
006| l = [ [ Null , data:-> [ -> 2, -> 3 ]] ]
007| return l[1]:[ -> Null, -> [ -> 2, -> 3 ] ]
019| newnode := make_stack_node( ~data data:[ -> 2, -> 3 ] ):-> [ -> Null, -> [ -> 2, -> 3 ] ]
020| if defined( ~arg this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ] )...
020| if defined( ~arg this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ] ):1
021| newnode[1]:[ -> Null, -> [ -> 1, -> 2 ] ] := this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ]
021| end # if
023| this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] := newnode:-> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ]
024| this{'ncount'}:2 = (this{'ncount'}:1 + 1):2
022|l{'push'}:sub ( ~data [ 3 , 4] )...
019| ... := make_stack_node( ~data data:[ -> 3, -> 4 ] )...
006| l = [ [ Null , data:-> [ -> 3, -> 4 ]] ]
007| return l[1]:[ -> Null, -> [ -> 3, -> 4 ] ]
019| newnode := make_stack_node( ~data data:[ -> 3, -> 4 ] ):-> [ -> Null, -> [ -> 3, -> 4 ] ]
020| if defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] )...
020| if defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] ):1
021| newnode[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] := this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ]
021| end # if
023| this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] := newnode:-> [ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ]
024| this{'ncount'}:3 = (this{'ncount'}:2 + 1):3
023|l{'push'}:sub ( ~data [ 5 , 6] )...
019| ... := make_stack_node( ~data data:[ -> 5, -> 6 ] )...
006| l = [ [ Null , data:-> [ -> 5, -> 6 ]] ]
007| return l[1]:[ -> Null, -> [ -> 5, -> 6 ] ]
019| newnode := make_stack_node( ~data data:[ -> 5, -> 6 ] ):-> [ -> Null, -> [ -> 5, -> 6 ] ]
020| if defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] )...
020| if defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] ):1
021| newnode[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] := this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ]
021| end # if
023| this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ], -> [ -> 5, -> 6 ] ] := newnode:-> [ -> [ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ], -> [ -> 5, -> 6 ] ]
024| this{'ncount'}:4 = (this{'ncount'}:3 + 1):4
025|while (l{'count'}:sub ( )...
046| return this{'ncount'}:4
025|while (l{'count'}:sub ( ):-> 4 != 0):true
026| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ], -> [ -> 5, -> 6 ] ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ], -> [ -> 5, -> 6 ] ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> [ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ], -> [ -> 5, -> 6 ] ]
036| this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] := rt[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ]
037| this{'ncount'}:3 = (this{'ncount'}:4 - 1):3
042| return rt[2]:[ -> 5, -> 6 ]
026| r = l{'pop'}:sub ( ):-> [ -> 5, -> 6 ]
027| println( ~msg join( ~array r:[ -> 5, -> 6 ] ~separator ' - ' )...
027| println( ~msg join( ~array r:[ -> 5, -> 6 ] ~separator ' - ' ):'5 - 6' )...
028|end
025|while (l{'count'}:sub ( )...
046| return this{'ncount'}:3
025|while (l{'count'}:sub ( ):-> 3 != 0):true
026| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> [ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ], -> [ -> 3, -> 4 ] ]
036| this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] := rt[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ]
037| this{'ncount'}:2 = (this{'ncount'}:3 - 1):2
042| return rt[2]:[ -> 3, -> 4 ]
026| r = l{'pop'}:sub ( ):-> [ -> 3, -> 4 ]
027| println( ~msg join( ~array r:[ -> 3, -> 4 ] ~separator ' - ' )...
027| println( ~msg join( ~array r:[ -> 3, -> 4 ] ~separator ' - ' ):'3 - 4' )...
028|end
025|while (l{'count'}:sub ( )...
046| return this{'ncount'}:2
025|while (l{'count'}:sub ( ):-> 2 != 0):true
026| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> [ -> Null, -> [ -> 1, -> 2 ] ], -> [ -> 2, -> 3 ] ]
036| this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ] := rt[1]:[ -> Null, -> [ -> 1, -> 2 ] ]
037| this{'ncount'}:1 = (this{'ncount'}:2 - 1):1
042| return rt[2]:[ -> 2, -> 3 ]
026| r = l{'pop'}:sub ( ):-> [ -> 2, -> 3 ]
027| println( ~msg join( ~array r:[ -> 2, -> 3 ] ~separator ' - ' )...
027| println( ~msg join( ~array r:[ -> 2, -> 3 ] ~separator ' - ' ):'2 - 3' )...
028|end
025|while (l{'count'}:sub ( )...
046| return this{'ncount'}:1
025|while (l{'count'}:sub ( ):-> 1 != 0):true
026| ... = l{'pop'}:sub ( )...
032| if not defined( ~arg this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ] )...
032| if not defined( ~arg this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ] ):1
033| end # if
035| rt := this{'head'}[1]:[ -> Null, -> [ -> 1, -> 2 ] ]
036| this{'head'}[1]:Null := rt[1]:Null
037| this{'ncount'}:0 = (this{'ncount'}:1 - 1):0
042| return rt[2]:[ -> 1, -> 2 ]
026| r = l{'pop'}:sub ( ):-> [ -> 1, -> 2 ]
027| println( ~msg join( ~array r:[ -> 1, -> 2 ] ~separator ' - ' )...
027| println( ~msg join( ~array r:[ -> 1, -> 2 ] ~separator ' - ' ):'1 - 2' )...
028|end
025|while (l{'count'}:sub ( )...
046| return this{'ncount'}:0
025|while (l{'count'}:sub ( ):-> 0 != 0):false
028|end # finish loop
032|print( ~msg '*** eof stack test ***' )...