Merge pull request #303 from ichiban/prioritize-max-depth-over-cycle-…

…detection prioritize max_depth over cycle detection
ichiban · Aug 11, 2023 · 982dbc1 · 982dbc1
2 parents b77736e + 4c60406
commit 982dbc1
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 1 deletion.
diff --git a/engine/builtin_test.go b/engine/builtin_test.go
@@ -4053,6 +4053,7 @@ func TestWriteTerm(t *testing.T) {
 		{title: `write_term(S, s(s(0)), [max_depth(2)]).`, sOrA: w, term: NewAtom("s").Apply(NewAtom("s").Apply(Integer(0))), options: List(atomMaxDepth.Apply(Integer(2))), ok: true, output: `s(s(...))`},
 		{title: `write_term(S, _, [max_depth(_)]).`, sOrA: w, term: NewVariable(), options: List(atomMaxDepth.Apply(NewVariable())), err: InstantiationError(nil)},
 		{title: `write_term(S, _, [max_depth(foo)]).`, sOrA: w, term: NewVariable(), options: List(atomMaxDepth.Apply(NewAtom("foo"))), err: domainError(validDomainWriteOption, atomMaxDepth.Apply(NewAtom("foo")), nil)},
+		{title: `L = [a, b|L], write_term(S, L, [max_depth(9)]).`, sOrA: w, term: l, options: List(atomMaxDepth.Apply(Integer(9))), env: NewEnv().bind(l, PartialList(l, NewAtom("a"), NewAtom("b"))), ok: true, output: `[a,b,a,b,a,b,a,b,a|...]`}, // https://github.com/ichiban/prolog/issues/297#issuecomment-1646750461
 	}
 
 	var vm VM

diff --git a/engine/compound.go b/engine/compound.go
@@ -78,7 +78,7 @@ func writeCompoundList(w io.Writer, c Compound, opts *WriteOptions, env *Env) er
 	opts = opts.withPriority(999).withLeft(operator{}).withRight(operator{})
 	_, _ = fmt.Fprint(&ew, "[")
 	_ = c.Arg(0).WriteTerm(&ew, opts, env)
-	iter := ListIterator{List: c.Arg(1), Env: env}
+	iter := ListIterator{List: c.Arg(1), Env: env, AllowCycle: opts.maxDepth > 0}
 	for iter.Next() {
 		opts.maxDepth--
 		if opts.maxDepth == 0 {