impl with_path

Author: uvlad7

.rubocop.yml

@@ -30,3 +30,12 @@ RSpec/ExampleLength:
 Metrics/BlockLength:
   Exclude:
     - "spec/**/*"
+
+Style/TrailingCommaInArguments:
+  EnforcedStyleForMultiline: consistent_comma
+
+Style/TrailingCommaInArrayLiteral:
+  EnforcedStyleForMultiline: consistent_comma
+
+Style/TrailingCommaInHashLiteral:
+  EnforcedStyleForMultiline: consistent_comma

ext/json_scanner/json_scanner.c

@@ -240,10 +240,10 @@ typedef enum
 } value_type;
 
 // noexcept
-void create_point(VALUE *point, scan_ctx *sctx, value_type type, size_t length, size_t curr_pos)
+VALUE create_point(scan_ctx *sctx, value_type type, size_t length, size_t curr_pos)
 {
   VALUE values[3];
-  *point = rb_ary_new_capa(3);
+  VALUE point = rb_ary_new_capa(3);
   // noexcept
   values[1] = RB_ULONG2NUM(curr_pos);
   switch (type)
@@ -275,14 +275,37 @@ void create_point(VALUE *point, scan_ctx *sctx, value_type type, size_t length,
     break;
   }
   // rb_ary_cat raise only in case of a frozen array or if len is too long
-  rb_ary_cat(*point, values, 3);
+  rb_ary_cat(point, values, 3);
+  return point;
+}
+
+// noexcept
+VALUE create_path(scan_ctx *sctx)
+{
+  VALUE path = rb_ary_new_capa(sctx->current_path_len);
+  for (int i = 0; i < sctx->current_path_len; i++)
+  {
+    VALUE entry;
+    switch (sctx->current_path[i].type)
+    {
+    case PATH_KEY:
+      entry = rb_str_new(sctx->current_path[i].value.key.val, sctx->current_path[i].value.key.len);
+      break;
+    case PATH_INDEX:
+      entry = RB_ULONG2NUM(sctx->current_path[i].value.index);
+      break;
+    }
+    rb_ary_push(path, entry);
+  }
+  return path;
 }
 
 // noexcept
 void save_point(scan_ctx *sctx, value_type type, size_t length)
 {
   // TODO: Abort parsing if all paths are matched and no more mathces are possible: only trivial key/index matchers at the current level
   // TODO: Don't re-compare already matched prefixes; hard to invalidate, though
+  // TODO: Might fail in case of no memory
   VALUE point = Qundef;
   int match;
   for (int i = 0; i < sctx->paths_len; i++)
@@ -320,7 +343,10 @@ void save_point(scan_ctx *sctx, value_type type, size_t length)
     {
       if (point == Qundef)
       {
-        create_point(&point, sctx, type, length, yajl_get_bytes_consumed(sctx->handle));
+        point = create_point(sctx, type, length, yajl_get_bytes_consumed(sctx->handle));
+        if (sctx->with_path) {
+          point = rb_ary_new_from_args(2, create_path(sctx), point);
+        }
       }
       // rb_ary_push raises only in case of a frozen array, which is not the case
       // rb_ary_entry is safe

json_scanner.gemspec

@@ -24,7 +24,7 @@ Gem::Specification.new do |spec|
   File.basename(__FILE__)
   spec.files = [
     *(Dir["{lib,sig,spec}/**/*"] - Dir["lib/**/*.{so,dylib,dll}"]),
-    *Dir["ext/json_scanner/{extconf.rb,json_scanner.c,json_scanner.h}"], "README.md"
+    *Dir["ext/json_scanner/{extconf.rb,json_scanner.c,json_scanner.h}"], "README.md",
   ].reject { |f| File.directory?(f) }
   spec.require_paths = ["lib"]
   spec.extensions = ["ext/json_scanner/extconf.rb"]

spec/json_scanner_spec.rb

@@ -12,12 +12,12 @@
     expect(result).to eq([[[1, 4, :string]], [[12, 13, :number]], [[0, 15, :array]]])
     expect(described_class.scan('"2"', [[]])).to eq([[[0, 3, :string]]])
     expect(
-      described_class.scan("[0,1,2,3,4,5,6,7]", [[(0..2)], [(4...6)]])
+      described_class.scan("[0,1,2,3,4,5,6,7]", [[(0..2)], [(4...6)]]),
     ).to eq(
-      [[[1, 2, :number], [3, 4, :number], [5, 6, :number]], [[9, 10, :number], [11, 12, :number]]]
+      [[[1, 2, :number], [3, 4, :number], [5, 6, :number]], [[9, 10, :number], [11, 12, :number]]],
     )
     expect(described_class.scan('{"a": 1}', [["a"], []])).to eq(
-      [[[6, 7, :number]], [[0, 8, :object]]]
+      [[[6, 7, :number]], [[0, 8, :object]]],
     )
   end
 
@@ -40,14 +40,14 @@
 
   it "allows to select ranges" do
     expect(
-      described_class.scan("[[1,2],[3,4]]", [[described_class::ANY_INDEX, described_class::ANY_INDEX]])
+      described_class.scan("[[1,2],[3,4]]", [[described_class::ANY_INDEX, described_class::ANY_INDEX]]),
     ).to eq(
-      [[[2, 3, :number], [4, 5, :number], [8, 9, :number], [10, 11, :number]]]
+      [[[2, 3, :number], [4, 5, :number], [8, 9, :number], [10, 11, :number]]],
     )
     expect(
-      described_class.scan("[[1,2],[3,4]]", [[described_class::ANY_INDEX, (0...1)]])
+      described_class.scan("[[1,2],[3,4]]", [[described_class::ANY_INDEX, (0...1)]]),
     ).to eq(
-      [[[2, 3, :number], [8, 9, :number]]]
+      [[[2, 3, :number], [8, 9, :number]]],
     )
   end
 
@@ -74,4 +74,27 @@
       described_class.scan "{1}", [], verbose_error: true
     end.to raise_error described_class::ParseError, /invalid object key(?=.*\(right here\))/m
   end
+
+  it "allows to return an actual path to the element" do
+    expect(
+      described_class.scan(
+        "[[1,2],[3,4]]",
+        [
+          [described_class::ANY_INDEX],
+          [described_class::ANY_INDEX, described_class::ANY_INDEX],
+        ],
+        with_path: true,
+      ),
+    ).to eq(
+      [
+        # result for first mathcer, each element array of two items:
+        # array of path elements and 3-element array start,end,type
+        [[[0], [1, 6, :array]], [[1], [7, 12, :array]]],
+        [
+          [[0, 0], [2, 3, :number]], [[0, 1], [4, 5, :number]],
+          [[1, 0], [8, 9, :number]], [[1, 1], [10, 11, :number]],
+        ],
+      ],
+    )
+  end
 end