Added support for JSON Lines

Added support for JSON Lines (http://jsonlines.org) using the `..` prefix.
Which when specified, treats the multi-lined document as an array.

For example:

```
{"name": "Gilbert", "age": 61}
{"name": "Alexa", "age": 34}
{"name": "May", "age": 57}
{"name": "Deloise", "age": 44}
```

```
..#                   >> 4
..1                   >> {"name": "Alexa", "age": 34}
..3                   >> {"name": "Deloise", "age": 44}
..#.name              >> ["Gilbert","Alexa","May","Deloise"]
..#[name="May"].age   >> 57
```

Closes #60

README.md

@@ -14,6 +14,7 @@
 
 GJSON is a Go package that provides a [fast](#performance) and [simple](#get-a-value) way to get values from a json document.
 It has features such as [one line retrieval](#get-a-value), [dot notation paths](#path-syntax), [iteration](#iterate-through-an-object-or-array).
+For a command-line tool that uses the GJSON syntax check out [JJ](https://github.com/tidwall/jj).
 
 Getting Started
 ===============
@@ -95,6 +96,43 @@ friends.#[age>45]#.last            >> ["Craig","Murphy"]
 friends.#[first%"D*"].last         >> "Murphy"
 ```
 
+## JSON Lines
+
+There also support for [JSON Lines](http://jsonlines.org/) using the `..` prefix.
+Which when specified, treats the multi-lined document as an array. 
+
+For example:
+
+```
+{"name": "Gilbert", "age": 61}
+{"name": "Alexa", "age": 34}
+{"name": "May", "age": 57}
+{"name": "Deloise", "age": 44}
+```
+
+```
+..#                   >> 4
+..1                   >> {"name": "Alexa", "age": 34}
+..3                   >> {"name": "Deloise", "age": 44}
+..#.name              >> ["Gilbert","Alexa","May","Deloise"]
+..#[name="May"].age   >> 57
+```
+
+The `ForEachLines` function will iterate through lines.
+
+```go
+gjson.ForEachLine(json, func(line gjson.Result) bool{
+    println(line.String())
+    return true
+})
+
+// Outputs:
+// {"name": "Gilbert", "age": 61}
+// {"name": "Alexa", "age": 34}
+// {"name": "May", "age": 57}
+// {"name": "Deloise", "age": 44}
+```
+
 ## Result Type
 
 GJSON supports the json types `string`, `number`, `bool`, and `null`. 

gjson.go

@@ -1128,7 +1128,7 @@ func parseArray(c *parseContext, i int, path string) (int, bool) {
 			partidx = int(n)
 		}
 	}
-	for i < len(c.json) {
+	for i < len(c.json)+1 {
 		if !rp.arrch {
 			pmatch = partidx == h
 			hit = pmatch && !rp.more
@@ -1137,8 +1137,16 @@ func parseArray(c *parseContext, i int, path string) (int, bool) {
 		if rp.alogok {
 			alog = append(alog, i)
 		}
-		for ; i < len(c.json); i++ {
+		for ; ; i++ {
-			switch c.json[i] {
+			var ch byte
+			if i > len(c.json) {
+				break
+			} else if i == len(c.json) {
+				ch = ']'
+			} else {
+				ch = c.json[i]
+			}
+			switch ch {
 			default:
 				continue
 			case '"':
@@ -1252,8 +1260,11 @@ func parseArray(c *parseContext, i int, path string) (int, bool) {
 					if rp.alogok {
 						var jsons = make([]byte, 0, 64)
 						jsons = append(jsons, '[')
+
 						for j, k := 0, 0; j < len(alog); j++ {
-							res := Get(c.json[alog[j]:], rp.alogkey)
+							_, res, ok := parseAny(c.json, alog[j], true)
+							if ok {
+								res := res.Get(rp.alogkey)
 								if res.Exists() {
 									if k > 0 {
 										jsons = append(jsons, ',')
@@ -1262,6 +1273,7 @@ func parseArray(c *parseContext, i int, path string) (int, bool) {
 									k++
 								}
 							}
+						}
 						jsons = append(jsons, ']')
 						c.value.Type = JSON
 						c.value.Raw = string(jsons)
@@ -1290,10 +1302,28 @@ func parseArray(c *parseContext, i int, path string) (int, bool) {
 	return i, false
 }
 
+// ForEachLine iterates through lines of JSON as specified by the JSON Lines
+// format (http://jsonlines.org/).
+// Each line is returned as a GJSON Result.
+func ForEachLine(json string, iterator func(line Result) bool) {
+	var res Result
+	var i int
+	for {
+		i, res, _ = parseAny(json, i, true)
+		if !res.Exists() {
+			break
+		}
+		if !iterator(res) {
+			return
+		}
+	}
+}
+
 type parseContext struct {
 	json  string
 	value Result
 	calcd bool
+	lines bool
 }
 
 // Get searches json for the specified path.
@@ -1329,6 +1359,10 @@ type parseContext struct {
 func Get(json, path string) Result {
 	var i int
 	var c = &parseContext{json: json}
+	if len(path) >= 2 && path[0] == '.' && path[1] == '.' {
+		c.lines = true
+		parseArray(c, 0, path[2:])
+	} else {
 		for ; i < len(c.json); i++ {
 			if c.json[i] == '{' {
 				i++
@@ -1341,6 +1375,7 @@ func Get(json, path string) Result {
 				break
 			}
 		}
+	}
 	if len(c.value.Raw) > 0 && !c.calcd {
 		jhdr := *(*reflect.StringHeader)(unsafe.Pointer(&json))
 		rhdr := *(*reflect.StringHeader)(unsafe.Pointer(&(c.value.Raw)))

gjson_test.go

@@ -1295,3 +1295,60 @@ func TestIssue58(t *testing.T) {
 		t.Fatalf("expected '%v', got '%v'", `{"uid": 1}`, res)
 	}
 }
+
+func TestObjectGrouping(t *testing.T) {
+	json := `
+[
+	true,
+	{"name":"tom"},
+	false,
+	{"name":"janet"},
+	null
+]
+`
+	res := Get(json, "#.name")
+	if res.String() != `["tom","janet"]` {
+		t.Fatalf("expected '%v', got '%v'", `["tom","janet"]`, res.String())
+	}
+}
+
+func TestJSONLines(t *testing.T) {
+	json := `
+true
+false
+{"name":"tom"}
+[1,2,3,4,5]
+{"name":"janet"}
+null
+12930.1203
+	`
+	paths := []string{"..#", "..0", "..2.name", "..#.name", "..6", "..7"}
+	ress := []string{"7", "true", "tom", `["tom","janet"]`, "12930.1203", ""}
+	for i, path := range paths {
+		res := Get(json, path)
+		if res.String() != ress[i] {
+			t.Fatalf("expected '%v', got '%v'", ress[i], res.String())
+		}
+	}
+
+	json = `
+{"name": "Gilbert", "wins": [["straight", "7♣"], ["one pair", "10♥"]]}
+{"name": "Alexa", "wins": [["two pair", "4♠"], ["two pair", "9♠"]]}
+{"name": "May", "wins": []}
+{"name": "Deloise", "wins": [["three of a kind", "5♣"]]}
+`
+
+	var i int
+	lines := strings.Split(strings.TrimSpace(json), "\n")
+	ForEachLine(json, func(line Result) bool {
+		if line.Raw != lines[i] {
+			t.Fatalf("expected '%v', got '%v'", lines[i], line.Raw)
+		}
+		i++
+		return true
+	})
+	if i != 4 {
+		t.Fatalf("expected '%v', got '%v'", 4, i)
+	}
+
+}