diff --git a/src/pkg/template/exec.go b/src/pkg/template/exec.go index eaa57ae8186..dbe6541dbf6 100644 --- a/src/pkg/template/exec.go +++ b/src/pkg/template/exec.go @@ -196,23 +196,25 @@ func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) { val, _ := indirect(s.evalPipeline(dot, r.Pipe)) // mark top of stack before any variables in the body are pushed. mark := s.mark() + oneIteration := func(index, elem reflect.Value) { + // Set top var (lexically the second if there are two) to the element. + if len(r.Pipe.Decl) > 0 { + s.setVar(1, elem) + } + // Set next var (lexically the first if there are two) to the index. + if len(r.Pipe.Decl) > 1 { + s.setVar(2, index) + } + s.walk(elem, r.List) + s.pop(mark) + } switch val.Kind() { case reflect.Array, reflect.Slice: if val.Len() == 0 { break } for i := 0; i < val.Len(); i++ { - elem := val.Index(i) - // Set top var (lexically the second if there are two) to the element. - if len(r.Pipe.Decl) > 0 { - s.setVar(1, elem) - } - // Set next var (lexically the first if there are two) to the index. - if len(r.Pipe.Decl) > 1 { - s.setVar(2, reflect.ValueOf(i)) - } - s.walk(elem, r.List) - s.pop(mark) + oneIteration(reflect.ValueOf(i), val.Index(i)) } return case reflect.Map: @@ -220,17 +222,23 @@ func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) { break } for _, key := range val.MapKeys() { - elem := val.MapIndex(key) - // Set top var (lexically the second if there are two) to the element. - if len(r.Pipe.Decl) > 0 { - s.setVar(1, elem) + oneIteration(key, val.MapIndex(key)) + } + return + case reflect.Chan: + if val.IsNil() { + break + } + i := 0 + for ; ; i++ { + elem, ok := val.Recv() + if !ok { + break } - // Set next var (lexically the first if there are two) to the key. - if len(r.Pipe.Decl) > 1 { - s.setVar(2, key) - } - s.walk(elem, r.List) - s.pop(mark) + oneIteration(reflect.ValueOf(i), elem) + } + if i == 0 { + break } return case reflect.Invalid: diff --git a/src/pkg/template/exec_test.go b/src/pkg/template/exec_test.go index 82f56e13cba..7e07e8c2dbc 100644 --- a/src/pkg/template/exec_test.go +++ b/src/pkg/template/exec_test.go @@ -391,6 +391,8 @@ var execTests = []execTest{ {"range $x $y MSIone", "{{range $x, $y := .MSIone}}<{{$x}}={{$y}}>{{end}}", "", tVal, true}, {"range $x PSI", "{{range $x := .PSI}}<{{$x}}>{{end}}", "<21><22><23>", tVal, true}, {"declare in range", "{{range $x := .PSI}}<{{$foo:=$x}}{{$x}}>{{end}}", "<21><22><23>", tVal, true}, + {"range count", `{{range $i, $x := count 5}}[{{$i}}]{{$x}}{{end}}`, "[0]a[1]b[2]c[3]d[4]e", tVal, true}, + {"range nil count", `{{range $i, $x := count 0}}{{else}}empty{{end}}`, "empty", tVal, true}, // Cute examples. {"or as if true", `{{or .SI "slice is empty"}}`, "[3 4 5]", tVal, true}, @@ -424,9 +426,29 @@ func oneArg(a string) string { return "oneArg=" + a } +// count returns a channel that will deliver n sequential 1-letter strings starting at "a" +func count(n int) chan string { + if n == 0 { + return nil + } + c := make(chan string) + go func() { + for i := 0; i < n; i++ { + c <- "abcdefghijklmnop"[i : i+1] + } + close(c) + }() + return c +} + func testExecute(execTests []execTest, set *Set, t *testing.T) { b := new(bytes.Buffer) - funcs := FuncMap{"zeroArgs": zeroArgs, "oneArg": oneArg, "typeOf": typeOf} + funcs := FuncMap{ + "count": count, + "oneArg": oneArg, + "typeOf": typeOf, + "zeroArgs": zeroArgs, + } for _, test := range execTests { tmpl := New(test.name).Funcs(funcs) _, err := tmpl.ParseInSet(test.input, set)