dump,json: Properly figure if compound or not

format/json/testdata/json.fqtest

@@ -2,7 +2,8 @@
 /json.gz:
 $ fq -d json . /test.json
     |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|                |
-    |                                               |                |.: {} /test.json (json)
+0x00|7b 0a 20 20 20 20 22 61 22 3a 20 31 32 33 2c 0a|{.    "a": 123,.|.: {} /test.json (json)
+*   |until 0x74.7 (end) (117)                       |                |
 $ fq -d json tovalue /test.json
 {
   "a": 123,
@@ -17,7 +18,8 @@ $ fq -d json tovalue /test.json
 }
 $ fq . /test.json
     |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|                |
-    |                                               |                |.: {} /test.json (json)
+0x00|7b 0a 20 20 20 20 22 61 22 3a 20 31 32 33 2c 0a|{.    "a": 123,.|.: {} /test.json (json)
+*   |until 0x74.7 (end) (117)                       |                |
 $ fq .b[1] /test.json
 2
 $ fq . /json.gz
@@ -57,4 +59,4 @@ $ fq tovalue /json.gz
 }
 $ fq .uncompressed /json.gz
    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|                |
-   |                                               |                |.uncompressed: {} (json)
+0x0|7b 22 61 22 3a 20 31 32 33 7d                  |{"a": 123}      |.uncompressed: {} (json)

pkg/interp/dump.go

@@ -24,6 +24,15 @@ const (
 	colField = 6
 )
 
+func isCompound(v *decode.Value) bool {
+	switch v.V.(type) {
+	case decode.Struct, decode.Array:
+		return true
+	default:
+		return false
+	}
+}
+
 func dumpEx(v *decode.Value, cw *columnwriter.Writer, depth int, rootV *decode.Value, rootDepth int, addrWidth int, opts Options) error {
 	deco := opts.Decorator
 	// no error check as we write into buffering column
@@ -75,8 +84,6 @@ func dumpEx(v *decode.Value, cw *columnwriter.Writer, depth int, rootV *decode.V
 	rootIndent := strings.Repeat(" ", rootDepth)
 	indent := strings.Repeat("  ", depth)
 
-	isSimple := false
-
 	if depth == 0 {
 		switch v.V.(type) {
 		case decode.Struct:
@@ -152,8 +159,6 @@ func dumpEx(v *decode.Value, cw *columnwriter.Writer, depth int, rootV *decode.V
 		if v.Description != "" {
 			cfmt(colField, fmt.Sprintf(" (%s)", deco.Value.F(v.Description)))
 		}
-
-		isSimple = true
 	}
 
 	if opts.Verbose {
@@ -245,8 +250,8 @@ func dumpEx(v *decode.Value, cw *columnwriter.Writer, depth int, rootV *decode.V
 	// log.Printf("opts: %#+v\n", opts)
 	// log.Printf("depth: %#+v\n", depth)
 
-	// has length and is a simple value or a collapsed struct/array
+	// has length and is not compound or a collapsed struct/array (max depth)
-	if v.Range.Len > 0 && (isSimple || (opts.Depth != 0 && opts.Depth == depth)) {
+	if v.Range.Len > 0 && (!isCompound(v) || (opts.Depth != 0 && opts.Depth == depth)) {
 		cfmt(colAddr, "%s%s\n",
 			rootIndent, deco.DumpAddr.F(num.PadFormatInt(startLineByte, opts.AddrBase, true, addrWidth)))
 

pkg/interp/testdata/value_json_array.fqtest

@@ -2,7 +2,7 @@
 $ fq -i -n '"[]" | json'
 json> (.) | ., tovalue, type, length?
    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|                |
-   |                                               |                |.: [0] unnamed (json)
+0x0|5b 5d|                                         |[]|             |.: [0] unnamed (json)
 []
 "array"
 0

pkg/interp/testdata/value_json_object.fqtest

@@ -2,7 +2,7 @@
 $ fq -i -n '"{}" | json'
 json> (.) | ., tovalue, type, length?
    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|                |
-   |                                               |                |.: {} unnamed (json)
+0x0|7b 7d|                                         |{}|             |.: {} unnamed (json)
 {}
 "object"
 0