dev.1

Author: f3ath

CHANGELOG.md

@@ -1,9 +1,12 @@
 ## [Unreleased]
+## [0.0.0+dev.1] - 2020-07-27
 ### Added
 - Tokenizer and AST
+- All-in-array selector
 
 ## 0.0.0+dev.0 - 2020-07-24
 ### Added
 - Basic design draft
 
-[Unreleased]: https://github.com/f3ath/jessie/compare/0.0.0+dev.0...HEAD
+[Unreleased]: https://github.com/f3ath/jessie/compare/0.0.0+dev.1...HEAD
+[0.0.0+dev.1]: https://github.com/f3ath/jessie/compare/0.0.0+dev.0...0.0.0+dev.1

README.md

@@ -2,9 +2,9 @@
 Jessie is a work-in-progress. Expect the API to change often. Feel free to join.
 
 ## Roadmap
-- [ ] Basic selectors: fields, indices
+- [x] Basic selectors: fields, indices
 - [ ] Recursive descent (`..`)
-- [ ] Wildcard (`*`)
+- [x] Wildcard (`*`)
 - [ ] Subscript (`[:2]`)
 - [ ] Slice (`[1:10:2]`)
 - [ ] Union (`book[0, 1]`, `book[author, title, price]`)

lib/jessie.dart

@@ -2,3 +2,4 @@
 library jessie;
 
 export 'package:jessie/src/json_path.dart';
+export 'package:jessie/src/result.dart';

lib/src/ast.dart

@@ -1,6 +1,7 @@
 class Node {
   Node(this.value);
 
+  /// Builds the AST from the list of tokens
   static Node build(List<String> tokens) {
     final root = Node(r'$');
     if (tokens.isEmpty) {
@@ -24,7 +25,7 @@ class Node {
           children.add(stack.removeLast());
         }
         final brackets = stack.removeLast();
-        brackets.children.addAll(children);
+        brackets.children.addAll(children.reversed);
         stack.last.children.add(brackets);
         continue;
       }
@@ -35,4 +36,6 @@ class Node {
 
   final String value;
   final children = <Node>[];
+
+  bool get isNumber => RegExp(r'^-?\d+$').hasMatch(value);
 }

lib/src/field.dart

@@ -1,7 +1,7 @@
 import 'package:jessie/src/ast.dart';
-import 'package:jessie/src/filter.dart';
-import 'package:jessie/src/match.dart';
-import 'package:jessie/src/root.dart';
+import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/selector/root.dart';
+import 'package:jessie/src/result.dart';
 import 'package:jessie/src/state.dart';
 import 'package:jessie/src/tokenize.dart';
 
@@ -14,14 +14,14 @@ class JsonPath {
     return JsonPath._(state.filter);
   }
 
-  JsonPath._(this._filter);
+  JsonPath._(this._selector);
 
-  final Filter _filter;
+  final Selector _selector;
 
   /// Filters the given [json].
   /// Returns an Iterable of all elements found
-  Iterable<PathMatch> filter(json) => _filter.call([PathMatch(json, '')]);
+  Iterable<Result> select(json) => _selector([Result(json, '')]);
 
   @override
-  String toString() => _filter.toString();
+  String toString() => _selector.toString();
 }

lib/src/filter.dart

@@ -0,0 +1,10 @@
+/// A single matching result
+class Result<T> {
+  Result(this.value, this.path);
+
+  /// The value
+  final T value;
+
+  /// JSONPath to this result
+  final String path;
+}

lib/src/index.dart

@@ -0,0 +1,18 @@
+import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/result.dart';
+
+class AllInArray extends Selector {
+  @override
+  Iterable<Result> call(Iterable<Result> results) =>
+      results.where((r) => r.value is List).map((r) {
+        final val = r.value as List;
+        final results = <Result>[];
+        for (var i = 0; i < val.length; i++) {
+          results.add(Result(val[i], r.path + '[$i]'));
+        }
+        return results;
+      }).expand((_) => _);
+
+  @override
+  String get expression => '[*]';
+}

lib/src/json_path.dart

@@ -0,0 +1,16 @@
+import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/result.dart';
+
+class Field extends Selector {
+  Field(this.name);
+
+  final String name;
+
+  @override
+  Iterable<Result> call(Iterable<Result> results) => results
+      .where((r) => r.value is Map && r.value.containsKey(name))
+      .map((r) => Result(r.value[name], r.path + toString()));
+
+  @override
+  String get expression => "['$name']";
+}

lib/src/match.dart

@@ -0,0 +1,16 @@
+import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/result.dart';
+
+class Index extends Selector {
+  Index(this.index);
+
+  final int index;
+
+  @override
+  Iterable<Result> call(Iterable<Result> results) => results
+      .where((r) => r.value is List && r.value.length > index + 1)
+      .map((r) => Result(r.value[index], r.path + toString()));
+
+  @override
+  String get expression => '[$index]';
+}

lib/src/result.dart

@@ -0,0 +1,13 @@
+import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/result.dart';
+
+class Root extends Selector {
+  const Root();
+
+  @override
+  Iterable<Result> call(Iterable<Result> results) =>
+      results.map((m) => Result(m.value, toString()));
+
+  @override
+  String get expression => r'$';
+}

lib/src/root.dart

@@ -0,0 +1,32 @@
+import 'package:jessie/src/result.dart';
+
+/// Converts a set of results into a set of results
+abstract class Selector {
+  const Selector();
+
+  /// Applies this filter to the [results]
+  Iterable<Result> call(Iterable<Result> results);
+
+  /// The filter expression as string
+  String get expression;
+
+  @override
+  String toString() => expression;
+
+  /// Combines this expression with the [other]
+  Selector then(Selector other) => _Chain(this, other);
+}
+
+class _Chain extends Selector {
+  _Chain(this.first, this.second);
+
+  final Selector first;
+
+  final Selector second;
+
+  @override
+  Iterable<Result> call(Iterable<Result> results) => second(first(results));
+
+  @override
+  String get expression => '$first$second';
+}

lib/src/selector/all_in_array.dart

@@ -1,37 +1,48 @@
 import 'package:jessie/src/ast.dart';
-import 'package:jessie/src/field.dart';
-import 'package:jessie/src/filter.dart';
-import 'package:jessie/src/index.dart';
+import 'package:jessie/src/selector/all_in_array.dart';
+import 'package:jessie/src/selector/field.dart';
+import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/selector/index.dart';
 
 abstract class State {
   State process(Node node);
 
-  Filter get filter;
+  Selector get filter;
 }
 
 class Ready implements State {
   Ready(this.filter);
 
   @override
-  final Filter filter;
+  final Selector filter;
 
   @override
   State process(Node node) {
     if (node.value == '[') {
-      return Ready(filter.then(Index(int.parse(node.children.first.value))));
+      return Ready(filter.then(_brackets(node.children)));
     }
     if (node.value == '.') {
       return AwaitingField(filter);
     }
     throw StateError('Got ${node.value} in $this');
   }
+
+  Selector _brackets(List<Node> nodes) {
+    if (nodes.length == 1) {
+      final node = nodes.single;
+      final val = node.value;
+      if (val == '*') return AllInArray();
+      if (node.isNumber) return Index(int.parse(nodes.first.value));
+    }
+    throw StateError('Unexpected bracket expression');
+  }
 }
 
 class AwaitingField implements State {
   AwaitingField(this.filter);
 
   @override
-  final Filter filter;
+  final Selector filter;
 
   @override
   State process(Node node) {

lib/src/selector/field.dart

@@ -1,3 +1,4 @@
+/// Parses a JSONPath expression into a list of tokens
 List<String> tokenize(String expr) {
   final tokens = <String>[];
   var pos = 0;

lib/src/selector/index.dart

@@ -1,10 +1,11 @@
 name: jessie
-version: 0.0.0+dev.0
-homepage: https://github.com/f3ath/jessie
+version: 0.0.0+dev.1
 description: JSONPath for Dart
-environment:
-  sdk: ">=2.8.0 <3.0.0"
+homepage: "https://github.com/f3ath/jessie"
 
 dev_dependencies:
-  test: ^1.9.0
   pedantic: ^1.9.0
+  test: ^1.9.0
+
+environment:
+  sdk: ">=2.8.0 <3.0.0"