chore: update readme with options

Author: evilmonkeyinc

README.md

@@ -67,6 +67,14 @@ This object is returned by the `Compile` function.
 
 The JSONPath struct represents a reusable compiled JSONPath query which supports the `Query`, and `QueryString` functions as detailed above.
 
+### Options
+
+Part of the JSONPath object, Options allows you to specify what additional functionality, if any, that you want to enable while querying data.
+
+You are able to enable index referencing support for maps for all tokens using `AllowMapReferenceByIndex` or use enable it for each token type individually.
+
+You are able to enable index referencing support for strings for all tokens using `AllowStringReferenceByIndex` or use enable it for each token type individually.
+
 ## Supported Syntax
 
 | syntax | name  | example |
@@ -118,8 +126,6 @@ can also be used with the subscript syntax `$.store.book[*]`
 
 allows for additional operators to be applied to the current object to retrieve a child element.
 
-It is possible to use indexes to reference elements in a map, the order is determined by the keys in alphabetical order.
-
 A negative value for an index is supported, resulting in the elements being counted in reverse, `-1` would represent the last item in the collection, `-2` the second last, and so on.
 
 ### Union
@@ -130,8 +136,6 @@ allows for a comma separated list of indices or keys to denote the elements to r
 
 It is possible to use script expressions to define the union keys i.e. `$.store.book[0,(@.length-1)]` returns the first and last elements of the book collection.
 
-It is possible to use indexes to reference elements in a map, the order is determined by the keys in alphabetical order.
-
 A negative value for an index is supported, resulting in the elements being counted in reverse, `-1` would represent the last item in the collection, `-2` the second last, and so on.
 
 ### Range
@@ -185,11 +189,13 @@ the length token will allow you to return the length of an array, map, slice, or
 
 If used with a map that has a key `length` it will return the corresponding value instead of the length of the map.
 
-### Subscript, Union, and Range with strings
+### Subscript, Union, and Range with maps and strings
+
+Using the Compile() function, and modifying the JSONPath Options, it is possible to use a map or a string in place of an array with the subscript `[1]` union `[1,2,3]` and range `[0:3]` operations. 
 
-It is possible to use a string in place of an array with the subscript `[1]` union `[1,2,3]` and range `[0:3]` operations, and instead of returning an array of characters instead will return a substring.
+For maps, the keys will be sorted into alphabetical order and they will be used to determine the index order. For example, if you had a map with strings `a` and `b`, regardless of the order, `a` would be the `0` index, and `b` the `1` index.
 
-For example if you applied `[0:3]` to the string `string` it would return `str`.
+For strings instead of returning an array of characters instead will return a substring. For example if you applied `[0:3]` to the string `string` it would return `str`.
 
 ## Supported standard evaluation operations
 

jsonpath_test.go

@@ -780,6 +780,75 @@ func Test_Query(t *testing.T) {
 	}
 }
 
+func Test_JSONPath_String(t *testing.T) {
+
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{
+			input:    "$.store.book[*].author",
+			expected: "$['store']['book'][*]['author']",
+		},
+		{
+			input:    "$..author",
+			expected: "$..['author']",
+		},
+		{
+			input:    "$.store.*",
+			expected: "$['store'][*]",
+		},
+		{
+			input:    "$.store..price",
+			expected: "$['store']..['price']",
+		},
+		{
+			input:    "$..book[2]",
+			expected: "$..['book'][2]",
+		},
+		{
+			input:    "$..book[(@.length-1)]",
+			expected: "$..['book'][(@.length-1)]",
+		},
+		{
+			input:    "$..book[-1:]",
+			expected: "$..['book'][-1:]",
+		},
+		{
+			input:    "$..book[0,1]",
+			expected: "$..['book'][0,1]",
+		},
+		{
+			input:    "$..book[:2]",
+			expected: "$..['book'][:2]",
+		},
+		{
+			input:    "$..book[?(@.isbn)]",
+			expected: "$..['book'][?(@.isbn)]",
+		},
+		{
+			input:    "$..book[?(@.price<10)]",
+			expected: "$..['book'][?(@.price<10)]",
+		},
+		{
+			input:    "$..*",
+			expected: "$..[*]",
+		},
+		{
+			input:    "$.store. book[0].author",
+			expected: "$['store']['book'][0]['author']",
+		},
+	}
+
+	for idx, test := range tests {
+		t.Run(fmt.Sprintf("%d", idx), func(t *testing.T) {
+			compiled, _ := Compile(test.input)
+			assert.Equal(t, test.expected, compiled.String())
+		})
+	}
+
+}
+
 func Test_JSONPath_compile(t *testing.T) {
 
 	type expected struct {

token/token.go

@@ -5,6 +5,10 @@ import (
 	"strings"
 )
 
+/** Feature request
+support double quotes in keys?
+**/
+
 // Token represents a component of a JSON Path query
 type Token interface {
 	Apply(root, current interface{}, next []Token) (interface{}, error)