Topological sort/Extracted top item
Given a mapping between items, and items they depend on, a topological sort orders items so that no item precedes an item it depends upon.
The compiling of a design in the VHDL language has the constraint that a file must be compiled after any file containing definitions it depends on. A tool exists that extracts file dependencies.
- Assume the file names are single words, given without their file extensions.
- Files mentioned as only dependants, have no dependants of their own, but their order of compiling must be given.
- Any self dependencies should be ignored.
A top level file is defined as a file that:
- Has dependents.
- Is not itself the dependent of another file
Task Description
Given the following file dependencies as an example:
FILE FILE DEPENDENCIES ==== ================= top1 des1 ip1 ip2 top2 des1 ip2 ip3 ip1 extra1 ip1a ipcommon ip2 ip2a ip2b ip2c ipcommon des1 des1a des1b des1c des1a des1a1 des1a2 des1c des1c1 extra1
The task is to create a program that given a graph of the dependency:
- Determines the top levels from the dependencies and show them.
- Extracts a compile order of files to compile any given (usually top level) file.
- Give a compile order for file top1.
- Give a compile order for file top2.
You may show how to compile multiple top levels as a stretch goal
Note: this task differs from task Topological sort in that the order for compiling any file might not include all files; and that checks for dependency cycles are not mandated.
- Cf.
C
Take code from Topological sort#c and add/change the following: <lang c>char input[] = "top1 des1 ip1 ip2\n" "top2 des1 ip2 ip3\n" "ip1 extra1 ip1a ipcommon\n" "ip2 ip2a ip2b ip2c ipcommon\n" "des1 des1a des1b des1c\n" "des1a des1a1 des1a2\n" "des1c des1c1 extra1\n";
... int find_name(item base, int len, const char *name) { int i; for (i = 0; i < len; i++) if (!strcmp(base[i].name, name)) return i; return -1; }
int depends_on(item base, int n1, int n2) { int i; if (n1 == n2) return 1; for (i = 0; i < base[n1].n_deps; i++) if (depends_on(base, base[n1].deps[i], n2)) return 1; return 0; }
void compile_order(item base, int n_items, int *top, int n_top) { int i, j, lvl; int d = 0; printf("Compile order for:"); for (i = 0; i < n_top; i++) { printf(" %s", base[top[i]].name); if (base[top[i]].depth > d) d = base[top[i]].depth; } printf("\n");
for (lvl = 1; lvl <= d; lvl ++) { printf("level %d:", lvl); for (i = 0; i < n_items; i++) { if (base[i].depth != lvl) continue; for (j = 0; j < n_top; j++) { if (depends_on(base, top[j], i)) { printf(" %s", base[i].name); break; } } } printf("\n"); } printf("\n"); }
int main() { int i, n, bad = -1; item items; n = parse_input(&items);
for (i = 0; i < n; i++) if (!items[i].depth && get_depth(items, i, bad) < 0) bad--;
int top[3]; top[0] = find_name(items, n, "top1"); top[1] = find_name(items, n, "top2"); top[2] = find_name(items, n, "ip1");
compile_order(items, n, top, 1); compile_order(items, n, top + 1, 1); compile_order(items, n, top, 2); compile_order(items, n, top + 2, 1);
return 0; }</lang>output (the last item is just to show that it doesn't have to be top level)<lang>Compile order for: top1 level 1: extra1 ip1a ipcommon ip2a ip2b ip2c des1b des1a1 des1a2 des1c1 level 2: ip1 ip2 des1a des1c level 3: des1 level 4: top1
Compile order for: top2 level 1: ip3 extra1 ipcommon ip2a ip2b ip2c des1b des1a1 des1a2 des1c1 level 2: ip2 des1a des1c level 3: des1 level 4: top2
Compile order for: top1 top2 level 1: ip3 extra1 ip1a ipcommon ip2a ip2b ip2c des1b des1a1 des1a2 des1c1 level 2: ip1 ip2 des1a des1c level 3: des1 level 4: top1 top2
Compile order for: ip1 level 1: extra1 ip1a ipcommon level 2: ip1</lang>
Go
<lang go>package main
import (
"fmt" "strings"
)
var data = ` FILE FILE DEPENDENCIES
=============
top1 des1 ip1 ip2 top2 des1 ip2 ip3 ip1 extra1 ip1a ipcommon ip2 ip2a ip2b ip2c ipcommon des1 des1a des1b des1c des1a des1a1 des1a2 des1c des1c1 extra1`
func main() {
g, dep, err := parseLibDep(data)
if err != nil {
fmt.Println(err)
return
}
// Task 1: Determine top levels. The input parser returns a list (dep)
// of libraries that are dependants of at least one other library.
// Top levels are then libraries in the graph that are not on this list.
var tops []string
for n := range g {
if !dep[n] {
tops = append(tops, n)
}
}
fmt.Println("Top levels:", tops)
// Task 2 is orderFrom method, below
showOrder(g, "top1") // Task 3
showOrder(g, "top2") // Task 4
showOrder(g, "top1", "top2") // Stretch
fmt.Println("Cycle examples:")
// reparse with a cyclic dependency
g, _, err = parseLibDep(data + `
des1a1 des1`)
if err != nil {
fmt.Println(err)
return
}
showOrder(g, "top1") // runs into cycle
showOrder(g, "ip1", "ip2") // does not involve cycle
}
func showOrder(g graph, target ...string) {
order, cyclic := g.orderFrom(target...)
if cyclic == nil {
reverse(order) // compile order is reverse of dependency order
fmt.Println("Target", target, "order:", order)
} else {
fmt.Println("Target", target, "cyclic dependencies:", cyclic)
}
}
func reverse(s []string) {
last := len(s) - 1
for i, e := range s[:len(s)/2] {
s[i], s[last-i] = s[last-i], e
}
}
type graph map[string][]string // adjacency list representation type depList map[string]bool
// parseLibDep parses the text format of the task and returns a dependency // graph and a list of nodes that are dependants of at least one other node. func parseLibDep(data string) (g graph, d depList, err error) {
lines := strings.Split(data, "\n")
if len(lines) < 3 || !strings.HasPrefix(lines[2], "=") {
return nil, nil, fmt.Errorf("data format")
}
lines = lines[3:]
g = graph{}
d = depList{}
for _, line := range lines {
libs := strings.Fields(line)
if len(libs) == 0 {
continue
}
lib := libs[0]
var deps []string
for _, dep := range libs[1:] {
g[dep] = g[dep]
if dep == lib {
continue
}
for i := 0; ; i++ {
if i == len(deps) {
deps = append(deps, dep)
d[dep] = true
break
}
if dep == deps[i] {
break
}
}
}
g[lib] = deps
}
return g, d, nil
}
// OrderFrom produces a topological ordering of the subgraph of g reachable // from a set of start nodes, where the subgraph is a directed acyclic graph. // If the subgraph contains a cycle, orderFrom returns the first cycle found // and returns a nil order. Cycles which are in the graph but not in the // subgraph reachable from start are not detected. func (g graph) orderFrom(start ...string) (order, cyclic []string) {
L := make([]string, len(g))
i := len(L)
temp := map[string]bool{}
perm := map[string]bool{}
var cycleFound bool
var cycleStart string
var visit func(string)
visit = func(n string) {
switch {
case temp[n]:
cycleFound = true
cycleStart = n
return
case perm[n]:
return
}
temp[n] = true
for _, m := range g[n] {
visit(m)
if cycleFound {
if cycleStart > "" {
cyclic = append(cyclic, n)
if n == cycleStart {
cycleStart = ""
}
}
return
}
}
delete(temp, n)
perm[n] = true
i--
L[i] = n
}
for _, n := range start {
if perm[n] {
continue
}
visit(n)
if cycleFound {
return nil, cyclic
}
}
return L[i:], nil
}</lang>
- Output:
Top levels: [top1 top2] Target [top1] order: [des1a1 des1a2 des1a des1b des1c1 extra1 des1c des1 ip1a ipcommon ip1 ip2a ip2b ip2c ip2 top1] Target [top2] order: [des1a1 des1a2 des1a des1b des1c1 extra1 des1c des1 ip2a ip2b ip2c ipcommon ip2 ip3 top2] Target [top1 top2] order: [des1a1 des1a2 des1a des1b des1c1 extra1 des1c des1 ip1a ipcommon ip1 ip2a ip2b ip2c ip2 top1 ip3 top2] Cycle examples: Target [top1] cyclic dependencies: [des1a1 des1a des1] Target [ip1 ip2] order: [extra1 ip1a ipcommon ip1 ip2a ip2b ip2c ip2]
J
Derived from the topological sort implementation:
<lang j>compileOrder=: dyad define
targets=. ;: x
parsed=. <@;:;._2 y
names=. ~.({.&>parsed),targets,;parsed
depends=. (> =@i.@#) names e.S:1 (#names){.parsed
depends=. (+. +./ .*.~)^:_ depends
b=. +./depends (] , #~) names e. targets
names (</.~ \: ~.@])&(keep&#) +/"1 depends
(b#names) (</.~ /: ~.@]) +/ }.+./ .*.~&(b#"1 b#depends)^:a: 1
)
topLevel=: [: ({.&> -. [:;}.&.>) <@;:;._2 </lang>
The changes include:
- Added an argument for the target(s) we wish to find dependencies for
- Make sure that these targets are included in our dependency structures
- Make sure that things we can depend on are included in our dependency structures
- Select these targets, and the things they depend on, once we know what depends on what
- When ordering names by dependencies:
- only consider names and dependencies we want to keep
- extract names grouped by their dependency chain length
Example:
<lang j>dependencies=: noun define
top1 des1 ip1 ip2 top2 des1 ip2 ip3 ip1 extra1 ip1a ipcommon ip2 ip2a ip2b ip2c ipcommon des1 des1a des1b des1c des1a des1a1 des1a2 des1c des1c1 extra1
)
>topLevel dependencies
top1 top2
;:inv@> 'top1' compileOrder dependencies
extra1 ip1a ipcommon ip2a ip2b ip2c des1b des1a1 des1a2 des1c1 ip1 ip2 des1a des1c des1 top1
;:inv@> 'top2' compileOrder dependencies
ip3 extra1 ipcommon ip2a ip2b ip2c des1b des1a1 des1a2 des1c1 ip2 des1a des1c des1 top2
;:inv@> 'top1 top2' compileOrder dependencies
ip3 extra1 ip1a ipcommon ip2a ip2b ip2c des1b des1a1 des1a2 des1c1 ip1 ip2 des1a des1c des1 top1 top2 </lang>
Java
<lang java>import java.util.*; import static java.util.Arrays.asList; import static java.util.stream.Collectors.toList;
public class TopologicalSort2 {
public static void main(String[] args) {
String s = "top1,top2,ip1,ip2,ip3,ip1a,ip2a,ip2b,ip2c,ipcommon,des1,"
+ "des1a,des1b,des1c,des1a1,des1a2,des1c1,extra1";
Graph g = new Graph(s, new int[][]{
{0, 10}, {0, 2}, {0, 3},
{1, 10}, {1, 3}, {1, 4},
{2, 17}, {2, 5}, {2, 9},
{3, 6}, {3, 7}, {3, 8}, {3, 9},
{10, 11}, {10, 12}, {10, 13},
{11, 14}, {11, 15},
{13, 16}, {13, 17},});
System.out.println("Top levels: " + g.toplevels());
String[] files = {"top1", "top2", "ip1"};
for (String f : files)
System.out.printf("Compile order for %s %s%n", f, g.compileOrder(f));
}
}
class Graph {
List<String> vertices; boolean[][] adjacency; int numVertices;
public Graph(String s, int[][] edges) {
vertices = asList(s.split(","));
numVertices = vertices.size();
adjacency = new boolean[numVertices][numVertices];
for (int[] edge : edges)
adjacency[edge[0]][edge[1]] = true;
}
List<String> toplevels() {
List<String> result = new ArrayList<>();
// look for empty columns
outer:
for (int c = 0; c < numVertices; c++) {
for (int r = 0; r < numVertices; r++) {
if (adjacency[r][c])
continue outer;
}
result.add(vertices.get(c));
}
return result;
}
List<String> compileOrder(String item) {
LinkedList<String> result = new LinkedList<>();
LinkedList<Integer> queue = new LinkedList<>();
queue.add(vertices.indexOf(item));
while (!queue.isEmpty()) {
int r = queue.poll();
for (int c = 0; c < numVertices; c++) {
if (adjacency[r][c] && !queue.contains(c)) {
queue.add(c);
}
}
result.addFirst(vertices.get(r));
}
return result.stream().distinct().collect(toList());
}
}</lang>
Top levels: [top1, top2] Compile order for top1 [extra1, des1c1, des1a2, des1a1, des1c, des1b, des1a, ip2c, ip2b, ip2a, ipcommon, ip1a, des1, ip2, ip1, top1] Compile order for top2 [extra1, des1c1, des1a2, des1a1, des1c, des1b, des1a, ipcommon, ip2c, ip2b, ip2a, des1, ip3, ip2, top2] Compile order for ip1 [extra1, ipcommon, ip1a, ip1]
Kotlin
<lang scala>// version 1.1.51
import java.util.LinkedList
val s = "top1, top2, ip1, ip2, ip3, ip1a, ip2a, ip2b, ip2c, ipcommon, des1, " +
"des1a, des1b, des1c, des1a1, des1a2, des1c1, extra1"
val deps = mutableListOf(
0 to 10, 0 to 2, 0 to 3, 1 to 10, 1 to 3, 1 to 4, 2 to 17, 2 to 5, 2 to 9, 3 to 6, 3 to 7, 3 to 8, 3 to 9, 10 to 11, 10 to 12, 10 to 13, 11 to 14, 11 to 15, 13 to 16, 13 to 17
)
val files = listOf("top1", "top2", "ip1")
class Graph(s: String, edges: List<Pair<Int, Int>>) {
val vertices = s.split(", ")
val numVertices = vertices.size
val adjacency = List(numVertices) { BooleanArray(numVertices) }
init {
for (edge in edges) adjacency[edge.first][edge.second] = true
}
fun topLevels(): List<String> {
val result = mutableListOf<String>()
// look for empty columns
outer@ for (c in 0 until numVertices) {
for (r in 0 until numVertices) {
if (adjacency[r][c]) continue@outer
}
result.add(vertices[c])
}
return result
}
fun compileOrder(item: String): List<String> {
val result = LinkedList<String>()
val queue = LinkedList<Int>()
queue.add(vertices.indexOf(item))
while (!queue.isEmpty()) {
val r = queue.poll()
for (c in 0 until numVertices) {
if (adjacency[r][c] && !queue.contains(c)) queue.add(c)
}
result.addFirst(vertices[r])
}
return result.distinct().toList()
}
}
fun main(args: Array<String>) {
val g = Graph(s, deps)
println("Top levels: ${g.topLevels()}")
for (f in files) println("\nCompile order for $f: ${g.compileOrder(f)}")
}</lang>
- Output:
Top levels: [top1, top2] Compile order for top1: [extra1, des1c1, des1a2, des1a1, des1c, des1b, des1a, ip2c, ip2b, ip2a, ipcommon, ip1a, des1, ip2, ip1, top1] Compile order for top2: [extra1, des1c1, des1a2, des1a1, des1c, des1b, des1a, ipcommon, ip2c, ip2b, ip2a, des1, ip3, ip2, top2] Compile order for ip1: [extra1, ipcommon, ip1a, ip1]
Perl 6
<lang perl6>sub top_topos ( %deps, *@top ) {
my %ba;
for %deps.kv -> $after, @befores {
for @befores -> $before {
%ba{$after}{$before} = 0 if $before ne $after;
%ba{$before} //= {};
}
}
if @top {
my @want = @top; my %care; %care{@want} = 1 xx *; repeat while @want { my @newwant; for @want -> $before { if %ba{$before} { for %ba{$before}.keys -> $after { if not %ba{$before}{$after} { %ba{$before}{$after}++; push @newwant, $after; } } } } @want = @newwant; %care{@want} = 1 xx *; }
for %ba.keys -> $before { %ba{$before}:delete unless %care{$before}; }
}
my @levels;
while %ba.grep( not *.value )».key -> @befores {
push @levels, ~@befores.sort;
%ba{@befores}:delete;
for %ba.values { .{@befores}:delete }
}
if @top {
say "For top-level-modules: ", @top; say " $_" for @levels;
}
else {
say "Top levels are: @levels[*-1]";
}
say "Cycle found! {%ba.keys.sort}" if %ba;
say ;
}
my %deps =
top1 => <des1 ip1 ip2>,
top2 => <des1 ip2 ip3>,
ip1 => <extra1 ip1a ipcommon>,
ip2 => <ip2a ip2b ip2c ipcommon>,
des1 => <des1a des1b des1c>,
des1a => <des1a1 des1a2>,
des1c => <des1c1 extra1>;
top_topos(%deps); top_topos(%deps, 'top1'); top_topos(%deps, 'top2'); top_topos(%deps, 'ip1'); top_topos(%deps, 'top1', 'top2');</lang>
- Output:
Top levels are: top1 top2 For top-level-modules: top1 des1a1 des1a2 des1b des1c1 extra1 ip1a ip2a ip2b ip2c ipcommon des1a des1c ip1 ip2 des1 top1 For top-level-modules: top2 des1a1 des1a2 des1b des1c1 extra1 ip2a ip2b ip2c ip3 ipcommon des1a des1c ip2 des1 top2 For top-level-modules: ip1 extra1 ip1a ipcommon ip1 For top-level-modules: top1 top2 des1a1 des1a2 des1b des1c1 extra1 ip1a ip2a ip2b ip2c ip3 ipcommon des1a des1c ip1 ip2 des1 top1 top2
Python
Where the compile order between a subset of files is arbitrary, they are shown on the same line. <lang python>try:
from functools import reduce
except: pass
- Python 3.x: def topx(data:'dict', tops:'set'=None) -> 'list':
def topx(data, tops=None):
'Extract the set of top-level(s) in topological order'
for k, v in data.items():
v.discard(k) # Ignore self dependencies
if tops is None:
tops = toplevels(data)
return _topx(data, tops, [], set())
def _topx(data, tops, _sofar, _sofar_set):
'Recursive topological extractor'
_sofar += [tops] # Accumulates order in reverse
_sofar_set.union(tops)
depends = reduce(set.union, (data.get(top, set()) for top in tops))
if depends:
_topx(data, depends, _sofar, _sofar_set)
ordered, accum = [], set()
for s in _sofar[::-1]:
ordered += [sorted(s - accum)]
accum |= s
return ordered
def printorder(order):
'Prettyprint topological ordering'
if order:
print("First: " + ', '.join(str(s) for s in order[0]))
for o in order[1:]:
print(" Then: " + ', '.join(str(s) for s in o))
def toplevels(data):
\
Extract all top levels from dependency data
Top levels are never dependents
for k, v in data.items():
v.discard(k) # Ignore self dependencies
dependents = reduce(set.union, data.values())
return set(data.keys()) - dependents
if __name__ == '__main__':
data = dict(
top1 = set('ip1 des1 ip2'.split()),
top2 = set('ip2 des1 ip3'.split()),
des1 = set('des1a des1b des1c'.split()),
des1a = set('des1a1 des1a2'.split()),
des1c = set('des1c1 extra1'.split()),
ip2 = set('ip2a ip2b ip2c ipcommon'.split()),
ip1 = set('ip1a ipcommon extra1'.split()),
)
tops = toplevels(data)
print("The top levels of the dependency graph are: " + ' '.join(tops))
for t in sorted(tops):
print("\nThe compile order for top level: %s is..." % t)
printorder(topx(data, set([t])))
if len(tops) > 1:
print("\nThe compile order for top levels: %s is..."
% ' and '.join(str(s) for s in sorted(tops)) )
printorder(topx(data, tops))</lang>
Sample Output
The top levels of the dependency graph are: top2 top1 The compile order for top level: top1 is... First: des1a1, des1a2, des1c1, extra1 Then: des1a, des1b, des1c, ip1a, ip2a, ip2b, ip2c, ipcommon Then: des1, ip1, ip2 Then: top1 The compile order for top level: top2 is... First: des1a1, des1a2, des1c1, extra1 Then: des1a, des1b, des1c, ip2a, ip2b, ip2c, ipcommon Then: des1, ip2, ip3 Then: top2 The compile order for top levels: top1 and top2 is... First: des1a1, des1a2, des1c1, extra1 Then: des1a, des1b, des1c, ip1a, ip2a, ip2b, ip2c, ipcommon Then: des1, ip1, ip2, ip3 Then: top1, top2
Racket
<lang racket>#lang racket (define dep-tree ; go straight for the hash, without parsing strings etc.
#hash((top1 . (des1 ip1 ip2))
(top2 . (des1 ip2 ip3))
(ip1 . (extra1 ip1a ipcommon))
(ip2 . (ip2a ip2b ip2c ipcommon))
(des1 . (des1a des1b des1c))
(des1a . (des1a1 des1a2))
(des1c . (des1c1 extra1))))
(define (build-tree Deps Top)
(define (build n b# d)
(hash-set b# n d))
(define (inner-b-t node visited built# depth)
(cond
[(hash-ref built# node #f)
built#]
[(member node visited)
(error 'build-tree "circular dependency tree at node: ~a" node)]
[(hash-ref Deps node #f)
=>
(λ (deps)
(define built#+
(for/fold ((built# built#)) ((dependency deps))
(if (equal? dependency node)
built#
(inner-b-t dependency (cons node visited) built# (add1 depth)))))
(build node built#+ depth))]
[else
(build node built# depth)]))
(define final-build# (inner-b-t Top null (hash) 1))
(define levels# (for/fold ((hsh# (hash))) (([k v] (in-hash final-build#)))
(hash-update hsh# v (curry cons k) null)))
(for/list ((lvl (in-list (sort (hash-keys levels#) >)))) (hash-ref levels# lvl)))
(define (print-build-order Deps Top)
(define build-order (build-tree Deps Top)) (printf "To build: ~s~%" Top) (for ((round build-order)) (printf "Build: ~a~%" round)) (newline))
(print-build-order dep-tree 'top1) (print-build-order dep-tree 'top2) (with-handlers [(exn? (λ (x) (displayln (exn-message x) (current-error-port))))]
(build-tree #hash((top . (des1 ip1)) (ip1 . (net netip)) (netip . (mac ip1))) 'top))</lang>
- Output:
To build: top1 Build: (extra1 des1c1 des1a2 des1a1) Build: (ip2c ip2b ip2a ipcommon ip1a des1b des1c des1a) Build: (des1 ip2 ip1) Build: (top1) To build: top2 Build: (extra1 des1c1 des1a2 des1a1) Build: (ip2c ip2b ip2a ipcommon des1b des1c des1a) Build: (ip3 des1 ip2) Build: (top2) build-tree: circular dependency tree at node: ip1
REXX
Where the compile order between a subset of files is arbitrary, they are shown on the same line.
This REXX version can handle multiple top levels.
<lang REXX>/*REXX program display s the compile order of jobs (indicating the dependencies). */
parse arg job /*obtain optional argument from the CL.*/
jobL. =; stage.=; #.=0; @.=; JL= /*define some handy-dandy variables. */
tree. =
tree.1= ' top1 des1 ip1 ip2 '
tree.2= ' top2 des1 ip2 ip3 '
tree.3= ' ip1 extra1 ip1a ipcommon '
tree.4= ' ip2 ip2a ip2b ip2c ipcommon '
tree.5= ' des1 des1a des1b des1c '
tree.6= ' des1a des1a1 des1a2 '
tree.7= ' des1c des1c1 extra1 '
$=
do j=1 while tree.j\== /*build job tree.*/
parse var tree.j x deps; @.x=space(deps) /*extract jobs. */
if wordpos(x,$)==0 then $=$ x /*Unique? Add it.*/
do k=1 for words(@.x); _=word(@.x,k)
if wordpos(_,$)==0 then $=space($ _)
end /*k*/
end /*j*/
!.=; !!.=
do j=1 for words($); x=word($,j); !.x.0=words(@.x)
do k=1 for !.x.0; !.x.k=word(@.x,k); !!.x.k=!.x.k
end /*k*/ /* [↑] build arrays of job departments*/
end /*j*/
do words($) /*process all the jobs specified. */
do j=1 for words($); x=word($,j); z=words(@.x); allN=1; m=0
if z==0 then do; #.x=1; iterate; end /*if no dependents, then skip this one.*/
do k=1 for z; y=!.x.k /*examine all the stage numbers. */
if datatype(y,'W') then m=max(m,y) /*find the highest stage number. */
else do; allN=0 /*at least one entry isn't numeric. */
if #.y\==0 then !.x.k=#.y
end /* [↑] replace with a number. */
end /*k*/
if allN & m\==0 then #.x=max(#.x,m+1) /*replace with the stage number max. */
end /*j*/ /* [↑] maybe set the stage number. */
end /*words($)*/
jobL.1=job /*define the bottom level jobList. */ s=1 /*define the stage level for jobList. */
do j=1; yyy=jobL.j
do r=1 for words(yyy) /*verify that there are no duplicates. */
do c=1 while c<words(yyy); z=word(yyy,c)
p=wordpos(z,yyy,c+1); if p\==0 then yyy=delword(yyy,p,1)
end /*c*/ /* [↑] Dup? Then delete it. */
end /*r*/
jobL.j=yyy
if yyy= then leave /*if null, then we're done with jobList*/
z=words(yyy) /*number of jobs in the jobList. */
s=s+1 /*bump the stage number. */
do k=1 for z; _=word(yyy,k) /*obtain a stage number for the job. */
jobL.s=jobL.s @._ /*add a job to a stage. */
end /*k*/
end /*j*/
do k=1 for s; JL=JL jobL.k; end /*build a complete jobList (JL). */
do s=1 for words(JL) /*process each job in the jobList. */ _=word(JL,s); level=#._ /*get the proper level for the job. */ stage.level=stage.level _ /*assign a level to job stage number. */ end /*s*/ /* [↑] construct various job stages. */
say '─────── The compile order for job: ' job; say
/* [↓] display the stages for the job.*/
do show=1 for s; if stage.show\== then say show stage.show; end
/*stick a fork in it, we're all done. */</lang>
output when using the input of: top1
─────── The compile order for job: top1 1 des1b extra1 ip1a ipcommon ip2a ip2b ip2c des1a1 des1a2 des1c1 extra1 2 ip1 ip2 des1a des1c 3 des1 4 top1
output when using the input of: top2
─────── The compile order for job: top2 1 ip3 des1b ip2a ip2b ip2c ipcommon des1a1 des1a2 des1c1 extra1 2 ip2 des1a des1c 3 des1 4 top2
output when using the input of: top1 top2
─────── The compile order for job: top1 top2 1 ip3 des1b extra1 ip1a ipcommon ip2a ip2b ip2c des1a1 des1a2 des1c1 extra1 2 ip1 ip2 des1a des1c 3 des1 4 top1 top2
Tcl
The topsort proc is taken from Topological sort#Tcl with {*} removed from the line commented so that results are returned by level:
<lang Tcl>package require Tcl 8.5 proc topsort {data} {
# Clean the data
dict for {node depends} $data {
if {[set i [lsearch -exact $depends $node]] >= 0} {
set depends [lreplace $depends $i $i]
dict set data $node $depends
}
foreach node $depends {dict lappend data $node}
}
# Do the sort
set sorted {}
while 1 {
# Find available nodes
set avail [dict keys [dict filter $data value {}]]
if {![llength $avail]} {
if {[dict size $data]} {
error "graph is cyclic, possibly involving nodes \"[dict keys $data]\""
}
return $sorted
}
lappend sorted $avail ;# change here: Topological sort had {*}$avail
# Remove from working copy of graph
dict for {node depends} $data {
foreach n $avail {
if {[set i [lsearch -exact $depends $n]] >= 0} {
set depends [lreplace $depends $i $i]
dict set data $node $depends
}
}
}
foreach node $avail {
dict unset data $node
}
}
}
- The changes to $data in this proc offer an interesting reflection on value semantics.
- Consider the value of $data seen by [dict for], by each invocation of [dict keys]
- and [dict unset] and how that affects the soundness of the loops.
proc tops {data} {
dict for {k v} $data {
foreach t [dict keys $data] {
if {$t in $v} {
dict unset data $t
}
}
}
dict keys $data
}
proc withdeps {dict tops {res {}}} {
foreach top $tops {
if {[dict exists $dict $top]} {
set deps [dict get $dict $top]
set res [dict merge $res [dict create $top $deps] [withdeps $dict $deps]]
}
}
return $res
}
proc parsetop {t} {
set top {}
foreach l [split $t \n] {
catch {dict lappend top {*}$l}
}
return $top
}
set inputData {
top1 des1 ip1 ip2
top2 des1 ip2 ip3
ip1 extra1 ip1a ipcommon
ip2 ip2a ip2b ip2c ipcommon
des1 des1a des1b des1c
des1a des1a1 des1a2
des1c des1c1 extra1
}
set d [parsetop $inputData] pdict $d set tops [tops $d]
puts "Tops: $tops\n"
set targets [list $tops {*}$tops] foreach target $targets {
puts "Target: $target"
set i 0
foreach deps [topsort [withdeps $d $target]] {
puts "\tround [incr i]:\t$deps"
}
}</lang>
- Output:
Tops: top1 top2
Target: top1 top2
round 1: des1b des1a1 des1a2 des1c1 extra1 ip1a ipcommon ip2a ip2b ip2c ip3
round 2: des1a des1c ip1 ip2
round 3: des1
round 4: top1 top2
Target: top1
round 1: des1b des1a1 des1a2 des1c1 extra1 ip1a ipcommon ip2a ip2b ip2c
round 2: des1a des1c ip1 ip2
round 3: des1
round 4: top1
Target: top2
round 1: ip3 des1b des1a1 des1a2 des1c1 extra1 ip2a ip2b ip2c ipcommon
round 2: des1a des1c ip2
round 3: des1
round 4: top2