Remove custom appengine and js builds

This commit allows for gjson and sjson to be supported in
WebAssembly `wasm` projects, but breaks compatibility for
anyone using gjson with older Google App Engine and GopherJS.

README.md

@@ -55,6 +55,9 @@ Prichard
 
 ## Path Syntax
 
+Below is a quick overview of the path syntax, for more complete information please
+check out [GJSON Syntax](SYNTAX.md).
+
 A path is a series of keys separated by a dot.
 A key may contain special wildcard characters '\*' and '?'.
 To access an array value use the index as the key.
@@ -68,9 +71,9 @@ The dot and wildcard characters can be escaped with '\\'.
   "children": ["Sara","Alex","Jack"],
   "fav.movie": "Deer Hunter",
   "friends": [
-    {"first": "Dale", "last": "Murphy", "age": 44},
-    {"first": "Roger", "last": "Craig", "age": 68},
-    {"first": "Jane", "last": "Murphy", "age": 47}
+    {"first": "Dale", "last": "Murphy", "age": 44, "nets": ["ig", "fb", "tw"]},
+    {"first": "Roger", "last": "Craig", "age": 68, "nets": ["fb", "tw"]},
+    {"first": "Jane", "last": "Murphy", "age": 47, "nets": ["ig", "tw"]}
   ]
 }
 ```
@@ -87,45 +90,24 @@ The dot and wildcard characters can be escaped with '\\'.
 "friends.1.last"     >> "Craig"
 ```
 
-You can also query an array for the first match by using `#[...]`, or find all matches with `#[...]#`. 
-Queries support the `==`, `!=`, `<`, `<=`, `>`, `>=` comparison operators and the simple pattern matching `%` operator.
+You can also query an array for the first match by using `#(...)`, or find all 
+matches with `#(...)#`. Queries support the `==`, `!=`, `<`, `<=`, `>`, `>=` 
+comparison operators and the simple pattern matching `%` (like) and `!%` 
+(not like) operators.
 
 ```
-friends.#[last=="Murphy"].first    >> "Dale"
-friends.#[last=="Murphy"]#.first   >> ["Dale","Jane"]
-friends.#[age>45]#.last            >> ["Craig","Murphy"]
-friends.#[first%"D*"].last         >> "Murphy"
+friends.#(last=="Murphy").first    >> "Dale"
+friends.#(last=="Murphy")#.first   >> ["Dale","Jane"]
+friends.#(age>45)#.last            >> ["Craig","Murphy"]
+friends.#(first%"D*").last         >> "Murphy"
+friends.#(first!%"D*").last        >> "Craig"
+friends.#(nets.#(=="fb"))#.first   >> ["Dale","Roger"]
 ```
 
-## JSON Lines
-
-There's support for [JSON Lines](http://jsonlines.org/) using the `..` prefix, which treats a multilined 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 JSON lines.
-
-```go
-gjson.ForEachLine(json, func(line gjson.Result) bool{
-    println(line.String())
-    return true
-})
-```
+*Please note that prior to v1.3.0, queries used the `#[...]` brackets. This was
+changed in v1.3.0 as to avoid confusion with the new
+[multipath](SYNTAX.md#multipaths) syntax. For backwards compatibility, 
+`#[...]` will continue to work until the next major release.*
 
 ## Result Type
 
@@ -193,6 +175,118 @@ result.Int() int64    // -9223372036854775808 to 9223372036854775807
 result.Uint() int64   // 0 to 18446744073709551615
 ```
 
+## Modifiers and path chaining 
+
+New in version 1.2 is support for modifier functions and path chaining.
+
+A modifier is a path component that performs custom processing on the 
+json.
+
+Multiple paths can be "chained" together using the pipe character. 
+This is useful for getting results from a modified query.
+
+For example, using the built-in `@reverse` modifier on the above json document,
+we'll get `children` array and reverse the order:
+
+```
+"children|@reverse"           >> ["Jack","Alex","Sara"]
+"children|@reverse|0"         >> "Jack"
+```
+
+There are currently the following built-in modifiers:
+
+- `@reverse`: Reverse an array or the members of an object.
+- `@ugly`: Remove all whitespace from a json document.
+- `@pretty`: Make the json document more human readable.
+- `@this`: Returns the current element. It can be used to retrieve the root element.
+- `@valid`: Ensure the json document is valid.
+- `@flatten`: Flattens an array.
+- `@join`: Joins multiple objects into a single object.
+
+### Modifier arguments
+
+A modifier may accept an optional argument. The argument can be a valid JSON 
+document or just characters.
+
+For example, the `@pretty` modifier takes a json object as its argument. 
+
+```
+@pretty:{"sortKeys":true} 
+```
+
+Which makes the json pretty and orders all of its keys.
+
+```json
+{
+  "age":37,
+  "children": ["Sara","Alex","Jack"],
+  "fav.movie": "Deer Hunter",
+  "friends": [
+    {"age": 44, "first": "Dale", "last": "Murphy"},
+    {"age": 68, "first": "Roger", "last": "Craig"},
+    {"age": 47, "first": "Jane", "last": "Murphy"}
+  ],
+  "name": {"first": "Tom", "last": "Anderson"}
+}
+```
+
+*The full list of `@pretty` options are `sortKeys`, `indent`, `prefix`, and `width`. 
+Please see [Pretty Options](https://github.com/tidwall/pretty#customized-output) for more information.*
+
+### Custom modifiers
+
+You can also add custom modifiers.
+
+For example, here we create a modifier that makes the entire json document upper
+or lower case.
+
+```go
+gjson.AddModifier("case", func(json, arg string) string {
+  if arg == "upper" {
+    return strings.ToUpper(json)
+  }
+  if arg == "lower" {
+    return strings.ToLower(json)
+  }
+  return json
+})
+```
+
+```
+"children|@case:upper"           >> ["SARA","ALEX","JACK"]
+"children|@case:lower|@reverse"  >> ["jack","alex","sara"]
+```
+
+## JSON Lines
+
+There's support for [JSON Lines](http://jsonlines.org/) using the `..` prefix, which treats a multilined 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 JSON lines.
+
+```go
+gjson.ForEachLine(json, func(line gjson.Result) bool{
+    println(line.String())
+    return true
+})
+```
+
 ## Get nested array values
 
 Suppose you want all the last names from the following json:
@@ -226,7 +320,7 @@ for _, name := range result.Array() {
 You can also query an object inside an array:
 
 ```go
-name := gjson.Get(json, `programmers.#[lastName="Hunter"].firstName`)
+name := gjson.Get(json, `programmers.#(lastName="Hunter").firstName`)
 println(name.String())  // prints "Elliotte"
 ```
 

SYNTAX.md

@@ -0,0 +1,277 @@
+# GJSON Path Syntax
+
+A GJSON Path is a text string syntax that describes a search pattern for quickly retreiving values from a JSON payload.
+
+This document is designed to explain the structure of a GJSON Path through examples.
+
+- [Path structure](#path-structure)
+- [Basic](#basic)
+- [Wildcards](#wildcards)
+- [Escape Character](#escape-character)
+- [Arrays](#arrays)
+- [Queries](#queries)
+- [Dot vs Pipe](#dot-vs-pipe)
+- [Modifiers](#modifiers)
+- [Multipaths](#multipaths)
+
+The definitive implemenation is [github.com/tidwall/gjson](https://github.com/tidwall/gjson).  
+Use the [GJSON Playground](https://gjson.dev) to experiment with the syntax online.
+
+
+## Path structure
+
+A GJSON Path is intended to be easily expressed as a series of components seperated by a `.` character. 
+
+Along with `.` character, there are a few more that have special meaning, including `|`, `#`, `@`, `\`, `*`, and `?`.
+
+## Example
+
+Given this JSON
+
+```json
+{
+  "name": {"first": "Tom", "last": "Anderson"},
+  "age":37,
+  "children": ["Sara","Alex","Jack"],
+  "fav.movie": "Deer Hunter",
+  "friends": [
+    {"first": "Dale", "last": "Murphy", "age": 44, "nets": ["ig", "fb", "tw"]},
+    {"first": "Roger", "last": "Craig", "age": 68, "nets": ["fb", "tw"]},
+    {"first": "Jane", "last": "Murphy", "age": 47, "nets": ["ig", "tw"]}
+  ]
+}
+```
+
+The following GJSON Paths evaluate to the accompanying values.
+
+### Basic 
+
+In many cases you'll just want to retreive values by object name or array index.
+
+```go
+name.last              "Anderson"
+name.first             "Tom"
+age                    37
+children               ["Sara","Alex","Jack"]
+children.0             "Sara"
+children.1             "Alex"
+friends.1              {"first": "Roger", "last": "Craig", "age": 68}
+friends.1.first        "Roger"
+```
+
+### Wildcards
+
+A key may contain the special wildcard characters `*` and `?`. 
+The `*` will match on any zero+ characters, and `?` matches on any one character.
+
+```go
+child*.2               "Jack"
+c?ildren.0             "Sara"
+```
+
+### Escape character
+
+Special purpose characters, such as `.`, `*`, and `?` can be escaped with `\`. 
+
+```go
+fav\.movie             "Deer Hunter"
+```
+
+You'll also need to make sure that the `\` character is correctly escaped when hardcoding a path in source code.
+
+```go
+res := gjson.Get(json, "fav\\.movie")  // must escape the slash
+res := gjson.Get(json, `fav\.movie`)   // no need to escape the slash 
+
+```
+
+### Arrays
+
+The `#` character allows for digging into JSON Arrays.
+
+To get the length of an array you'll just use the `#` all by itself.
+
+```go
+friends.#              3
+friends.#.age         [44,68,47]
+```
+
+### Queries
+
+You can also query an array for the first match by  using `#(...)`, or find all matches with `#(...)#`. 
+Queries support the `==`, `!=`, `<`, `<=`, `>`, `>=` comparison operators, 
+and the simple pattern matching `%` (like) and `!%` (not like) operators.
+
+```go
+friends.#(last=="Murphy").first     "Dale"
+friends.#(last=="Murphy")#.first    ["Dale","Jane"]
+friends.#(age>45)#.last             ["Craig","Murphy"]
+friends.#(first%"D*").last          "Murphy"
+friends.#(first!%"D*").last         "Craig"
+```
+
+To query for a non-object value in an array, you can forgo the string to the right of the operator.
+
+```go
+children.#(!%"*a*")                 "Alex"
+children.#(%"*a*")#                 ["Sara","Jack"]
+```
+
+Nested queries are allowed.
+
+```go
+friends.#(nets.#(=="fb"))#.first  >> ["Dale","Roger"]
+```
+
+*Please note that prior to v1.3.0, queries used the `#[...]` brackets. This was
+changed in v1.3.0 as to avoid confusion with the new [multipath](#multipaths) 
+syntax. For backwards compatibility, `#[...]` will continue to work until the
+next major release.*
+
+### Dot vs Pipe
+
+The `.` is standard separator, but it's also possible to use a `|`. 
+In most cases they both end up returning the same results.
+The cases where`|` differs from `.` is when it's used after the `#` for [Arrays](#arrays) and [Queries](#queries). 
+
+Here are some examples
+
+```go
+friends.0.first                     "Dale"
+friends|0.first                     "Dale"
+friends.0|first                     "Dale"
+friends|0|first                     "Dale"
+friends|#                           3
+friends.#                           3
+friends.#(last="Murphy")#           [{"first": "Dale", "last": "Murphy", "age": 44},{"first": "Jane", "last": "Murphy", "age": 47}]
+friends.#(last="Murphy")#.first     ["Dale","Jane"]
+friends.#(last="Murphy")#|first     <non-existent>
+friends.#(last="Murphy")#.0         []
+friends.#(last="Murphy")#|0         {"first": "Dale", "last": "Murphy", "age": 44}
+friends.#(last="Murphy")#.#         []
+friends.#(last="Murphy")#|#         2
+```
+
+Let's break down a few of these.
+
+The path `friends.#(last="Murphy")#` all by itself results in
+
+```json
+[{"first": "Dale", "last": "Murphy", "age": 44},{"first": "Jane", "last": "Murphy", "age": 47}]
+```
+
+The `.first` suffix will process the `first` path on each array element *before* returning the results. Which becomes
+
+```json
+["Dale","Jane"]
+```
+
+But the `|first` suffix actually processes the `first` path *after* the previous result. 
+Since the previous result is an array, not an object, it's not possible to process 
+because `first` does not exist.
+
+Yet, `|0` suffix returns
+
+```json
+{"first": "Dale", "last": "Murphy", "age": 44}
+```
+
+Because `0` is the first index of the previous result.
+
+### Modifiers
+
+A modifier is a path component that performs custom processing on the JSON.
+
+For example, using the built-in `@reverse` modifier on the above JSON payload will reverse the `children` array:
+
+```go
+children.@reverse                   ["Jack","Alex","Sara"]
+children.@reverse.0                 "Jack"
+```
+
+There are currently the following built-in modifiers:
+
+- `@reverse`: Reverse an array or the members of an object.
+- `@ugly`: Remove all whitespace from JSON.
+- `@pretty`: Make the JSON more human readable.
+- `@this`: Returns the current element. It can be used to retrieve the root element.
+- `@valid`: Ensure the json document is valid.
+- `@flatten`: Flattens an array.
+- `@join`: Joins multiple objects into a single object.
+
+#### Modifier arguments
+
+A modifier may accept an optional argument. The argument can be a valid JSON payload or just characters.
+
+For example, the `@pretty` modifier takes a json object as its argument.
+
+```
+@pretty:{"sortKeys":true}
+```
+
+Which makes the json pretty and orders all of its keys.
+
+```json
+{
+  "age":37,
+  "children": ["Sara","Alex","Jack"],
+  "fav.movie": "Deer Hunter",
+  "friends": [
+    {"age": 44, "first": "Dale", "last": "Murphy"},
+    {"age": 68, "first": "Roger", "last": "Craig"},
+    {"age": 47, "first": "Jane", "last": "Murphy"}
+  ],
+  "name": {"first": "Tom", "last": "Anderson"}
+}
+```
+
+*The full list of `@pretty` options are `sortKeys`, `indent`, `prefix`, and `width`. 
+Please see [Pretty Options](https://github.com/tidwall/pretty#customized-output) for more information.*
+
+#### Custom modifiers
+
+You can also add custom modifiers. 
+
+For example, here we create a modifier which makes the entire JSON payload upper or lower case.
+
+```go
+gjson.AddModifier("case", func(json, arg string) string {
+  if arg == "upper" {
+    return strings.ToUpper(json)
+  }
+  if arg == "lower" {
+    return strings.ToLower(json)
+  }
+  return json
+})
+"children.@case:upper"             ["SARA","ALEX","JACK"]
+"children.@case:lower.@reverse"    ["jack","alex","sara"]
+```
+
+### Multipaths
+
+Starting with v1.3.0, GJSON added the ability to join multiple paths together
+to form new documents. Wrapping comma-separated paths between `{...}` or 
+`[...]` will result in a new array or object, respectively.
+
+For example, using the given multipath 
+
+```
+{name.first,age,"the_murphys":friends.#(last="Murphy")#.first}
+```
+
+Here we selected the first name, age, and the first name for friends with the 
+last name "Murphy".
+
+You'll notice that an optional key can be provided, in this case 
+"the_murphys", to force assign a key to a value. Otherwise, the name of the 
+actual field will be used, in this case "first". If a name cannot be
+determined, then "_" is used.
+
+This results in
+
+```
+{"first":"Tom","age":37,"the_murphys":["Dale","Jane"]}
+```
+
+

gjson_gae.go

@@ -1,10 +0,0 @@
-//+build appengine
-
-package gjson
-
-func getBytes(json []byte, path string) Result {
-	return Get(string(json), path)
-}
-func fillIndex(json string, c *parseContext) {
-	// noop. Use zero for the Index value.
-}

gjson_ngae.go

@@ -1,73 +0,0 @@
-//+build !appengine
-
-package gjson
-
-import (
-	"reflect"
-	"unsafe"
-)
-
-// getBytes casts the input json bytes to a string and safely returns the
-// results as uniquely allocated data. This operation is intended to minimize
-// copies and allocations for the large json string->[]byte.
-func getBytes(json []byte, path string) Result {
-	var result Result
-	if json != nil {
-		// unsafe cast to string
-		result = Get(*(*string)(unsafe.Pointer(&json)), path)
-		result = fromBytesGet(result)
-	}
-	return result
-}
-
-func fromBytesGet(result Result) Result {
-	// safely get the string headers
-	rawhi := *(*reflect.StringHeader)(unsafe.Pointer(&result.Raw))
-	strhi := *(*reflect.StringHeader)(unsafe.Pointer(&result.Str))
-	// create byte slice headers
-	rawh := reflect.SliceHeader{Data: rawhi.Data, Len: rawhi.Len}
-	strh := reflect.SliceHeader{Data: strhi.Data, Len: strhi.Len}
-	if strh.Data == 0 {
-		// str is nil
-		if rawh.Data == 0 {
-			// raw is nil
-			result.Raw = ""
-		} else {
-			// raw has data, safely copy the slice header to a string
-			result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh)))
-		}
-		result.Str = ""
-	} else if rawh.Data == 0 {
-		// raw is nil
-		result.Raw = ""
-		// str has data, safely copy the slice header to a string
-		result.Str = string(*(*[]byte)(unsafe.Pointer(&strh)))
-	} else if strh.Data >= rawh.Data &&
-		int(strh.Data)+strh.Len <= int(rawh.Data)+rawh.Len {
-		// Str is a substring of Raw.
-		start := int(strh.Data - rawh.Data)
-		// safely copy the raw slice header
-		result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh)))
-		// substring the raw
-		result.Str = result.Raw[start : start+strh.Len]
-	} else {
-		// safely copy both the raw and str slice headers to strings
-		result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh)))
-		result.Str = string(*(*[]byte)(unsafe.Pointer(&strh)))
-	}
-	return result
-}
-
-// fillIndex finds the position of Raw data and assigns it to the Index field
-// of the resulting value. If the position cannot be found then Index zero is
-// used instead.
-func fillIndex(json string, c *parseContext) {
-	if len(c.value.Raw) > 0 && !c.calcd {
-		jhdr := *(*reflect.StringHeader)(unsafe.Pointer(&json))
-		rhdr := *(*reflect.StringHeader)(unsafe.Pointer(&(c.value.Raw)))
-		c.value.Index = int(rhdr.Data - jhdr.Data)
-		if c.value.Index < 0 || c.value.Index >= len(json) {
-			c.value.Index = 0
-		}
-	}
-}

go.mod

@@ -0,0 +1,8 @@
+module github.com/tidwall/gjson
+
+go 1.12
+
+require (
+	github.com/tidwall/match v1.0.1
+	github.com/tidwall/pretty v1.0.0
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/tidwall/match v1.0.1 h1:PnKP62LPNxHKTwvHHZZzdOAOCtsJTjo6dZLCwpKm5xc=
+github.com/tidwall/match v1.0.1/go.mod h1:LujAq0jyVjBy028G1WhWfIzbpQfMO8bBZ6Tyb0+pL9E=
+github.com/tidwall/pretty v1.0.0 h1:HsD+QiTn7sK6flMKIvNmpqz1qrpP3Ps6jOKIKMooyg4=
+github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=