Merge pull request #2739 from crystal-lang/feature/yaml_union

Add YAML::PullParser#read_raw and support parsing unions. Fixes #2714
crystal-lang · Jun 3, 2016 · 8bfa519 · 8bfa519
2 parents a3c5d7a + 86192ff
commit 8bfa519
Showing 4 changed files with 87 additions and 1 deletion.
diff --git a/spec/std/yaml/serialization_spec.cr b/spec/std/yaml/serialization_spec.cr
@@ -104,6 +104,12 @@ describe "YAML serialization" do
         end
       end
     end
+
+    {% if Crystal::VERSION == "0.18.0" %}
+      it "deserializes union" do
+        Array(Int32 | String).from_yaml(%([1, "hello"])).should eq([1, "hello"])
+      end
+    {% end %}
   end
 
   describe "to_yaml" do

diff --git a/spec/std/yaml/yaml_pull_parser_spec.cr b/spec/std/yaml/yaml_pull_parser_spec.cr
@@ -1,6 +1,17 @@
 require "spec"
 require "yaml"
 
+private def assert_raw(string, expected = string, file = __FILE__, line = __LINE__)
+  it "parses raw #{string.inspect}", file, line do
+    pull = YAML::PullParser.new(string)
+    pull.read_stream do
+      pull.read_document do
+        pull.read_raw.should eq(expected)
+      end
+    end
+  end
+end
+
 module YAML
   describe PullParser do
     it "reads empty stream" do
@@ -95,5 +106,11 @@ module YAML
         end
       end
     end
+
+    assert_raw %(hello)
+    assert_raw %("hello"), %(hello)
+    assert_raw %(["hello"])
+    assert_raw %(["hello","world"])
+    assert_raw %({"hello":"world"})
   end
 end
diff --git a/src/yaml/from_yaml.cr b/src/yaml/from_yaml.cr
@@ -29,7 +29,11 @@ end
 
 {% for type in %w(Int8 Int16 Int32 Int64 UInt8 UInt16 UInt32 UInt64) %}
   def {{type.id}}.new(pull : YAML::PullParser)
-    {{type.id}}.new(pull.read_scalar)
+    begin
+      {{type.id}}.new(pull.read_scalar)
+    rescue ex
+      raise YAML::ParseException.new(ex.message.not_nil!, 0, 0)
+    end
   end
 {% end %}
 
@@ -133,6 +137,20 @@ def Enum.new(pull : YAML::PullParser)
   end
 end
 
+{% if Crystal::VERSION == "0.18.0" %}
+  def Union.new(pull : YAML::PullParser)
+    string = pull.read_raw
+    \{% for type in T %}
+      begin
+        return \{{type}}.from_yaml(string)
+      rescue YAML::ParseException
+        # Ignore
+      end
+    \{% end %}
+    raise YAML::ParseException.new("couldn't parse #{self} from #{string}", 0, 0)
+  end
+{% end %}
+
 struct Time::Format
   def from_yaml(pull : YAML::PullParser)
     string = pull.read_scalar

diff --git a/src/yaml/pull_parser.cr b/src/yaml/pull_parser.cr
@@ -147,6 +147,51 @@ class YAML::PullParser
     read_next
   end
 
+  def read_raw
+    case kind
+    when EventKind::SCALAR
+      self.value.not_nil!.tap { read_next }
+    when EventKind::SEQUENCE_START, EventKind::MAPPING_START
+      String.build { |io| read_raw(io) }
+    else
+      parse_exception "unexpected kind: #{kind}"
+    end
+  end
+
+  def read_raw(io)
+    case kind
+    when EventKind::SCALAR
+      self.value.not_nil!.inspect(io)
+      read_next
+    when EventKind::SEQUENCE_START
+      io << "["
+      read_next
+      first = true
+      while kind != EventKind::SEQUENCE_END
+        io << "," unless first
+        read_raw(io)
+        first = false
+      end
+      io << "]"
+      read_next
+    when EventKind::MAPPING_START
+      io << "{"
+      read_next
+      first = true
+      while kind != EventKind::MAPPING_END
+        io << "," unless first
+        read_raw(io)
+        io << ":"
+        read_raw(io)
+        first = false
+      end
+      io << "}"
+      read_next
+    else
+      parse_exception "unexpected kind: #{kind}"
+    end
+  end
+
   def skip
     case kind
     when EventKind::SCALAR