Tag, TagList, TagListParser

A lot of things in MM are structured like :tag[value]trailer and this formalizes that structure
sarbian · Jul 4, 2018 · ee3e340 · ee3e340
1 parent 106581c
commit ee3e340
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Showing 8 changed files with 672 additions and 0 deletions.
diff --git a/ModuleManager/ModuleManager.csproj b/ModuleManager/ModuleManager.csproj
@@ -75,6 +75,9 @@
     <Compile Include="Properties\Resources.Designer.cs" />
     <Compile Include="Progress\IPatchProgress.cs" />
     <Compile Include="Progress\PatchProgress.cs" />
+    <Compile Include="Tags\Tag.cs" />
+    <Compile Include="Tags\TagList.cs" />
+    <Compile Include="Tags\TagListParser.cs" />
     <Compile Include="Threading\ITaskStatus.cs" />
     <Compile Include="Threading\TaskStatus.cs" />
     <Compile Include="Threading\TaskStatusWrapper.cs" />

diff --git a/ModuleManager/Tags/Tag.cs b/ModuleManager/Tags/Tag.cs
@@ -0,0 +1,34 @@
+using System;
+
+namespace ModuleManager.Tags
+{
+    public struct Tag
+    {
+        public readonly string key;
+        public readonly string value;
+        public readonly string trailer;
+
+        public Tag(string key, string value, string trailer)
+        {
+            this.key = key ?? throw new ArgumentNullException(nameof(key));
+            if (key == string.Empty) throw new ArgumentException("can't be empty", nameof(key));
+
+            if (value == null && trailer != null)
+                throw new ArgumentException("trailer must be null if value is null");
+
+            if (trailer == string.Empty) throw new ArgumentException("can't be empty (null allowed)", nameof(trailer));
+
+            this.value = value;
+            this.trailer = trailer;
+        }
+
+        public override string ToString()
+        {
+            string s = "< '" + key + "' ";
+            if (value != null) s += "[ '" + value + "' ] ";
+            if (trailer != null) s += "'" + trailer + "' ";
+            s += ">";
+            return s;
+        }
+    }
+}
diff --git a/ModuleManager/Tags/TagList.cs b/ModuleManager/Tags/TagList.cs
@@ -0,0 +1,30 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using ModuleManager.Collections;
+
+namespace ModuleManager.Tags
+{
+    public interface ITagList : IEnumerable<Tag>
+    {
+        Tag PrimaryTag { get; }
+    }
+
+    public class TagList : ITagList
+    {
+        private readonly Tag[] tags;
+
+        public TagList(Tag primaryTag, IEnumerable<Tag> tags)
+        {
+            PrimaryTag = primaryTag;
+            this.tags = tags?.ToArray() ?? throw new ArgumentNullException(nameof(tags));
+        }
+
+        public Tag PrimaryTag { get; private set; }
+
+        public ArrayEnumerator<Tag> GetEnumerator() => new ArrayEnumerator<Tag>(tags);
+        IEnumerator<Tag> IEnumerable<Tag>.GetEnumerator() => GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+    }
+}
diff --git a/ModuleManager/Tags/TagListParser.cs b/ModuleManager/Tags/TagListParser.cs
@@ -0,0 +1,160 @@
+using System;
+using System.Collections.Generic;
+
+namespace ModuleManager.Tags
+{
+    public interface ITagListParser
+    {
+        ITagList Parse(string ToParse);
+    }
+
+    public class TagListParser : ITagListParser
+    {
+        public ITagList Parse(string toParse)
+        {
+            if (toParse == null) throw new ArgumentNullException(nameof(toParse));
+            if (toParse.Length == 0) throw new FormatException("can't create tag list from empty string");
+            if (toParse[0] == '[') throw new FormatException("can't create tag list beginning with [");
+            if (toParse[0] == ':') throw new FormatException("can't create tag list beginning with :");
+            if (toParse[toParse.Length - 1] == ':') throw new FormatException("tag list can't end with :");
+
+            List<Tag> tags = new List<Tag>();
+            Tag primaryTag = ParsePrimaryTag(toParse, ref tags);
+            return new TagList(primaryTag, tags);
+        }
+
+        private static Tag ParsePrimaryTag(string toParse, ref List<Tag> tags)
+        {
+            for (int i = 1; i < toParse.Length; i++)
+            {
+                char c = toParse[i];
+
+                if (c == '[')
+                {
+                    int j = ClosingBracketIndex(toParse, i + 1);
+                    return ParsePrimaryTrailer(toParse, j + 1, ref tags, toParse.Substring(0, i), toParse.Substring(i + 1, j - i - 1));
+                }
+                else if (c == ':')
+                {
+                    ParseTag(toParse, i + 1, ref tags);
+                    return new Tag(toParse.Substring(0, i), null, null);
+                }
+                else if (c == ']')
+                {
+                    throw new FormatException("encountered closing bracket in primary key");
+                }
+            }
+
+            return new Tag(toParse, null, null);
+        }
+
+        private static Tag ParsePrimaryTrailer(string toParse, int start, ref List<Tag> tags, string primaryKey, string primaryValue)
+        {
+            for (int i = start; i < toParse.Length; i++)
+            {
+                char c = toParse[i];
+
+                if (c == ':')
+                {
+                    string trailer = i == start ? null : toParse.Substring(start, i - start);
+                    ParseTag(toParse, i + 1, ref tags);
+                    return new Tag(primaryKey, primaryValue, trailer);
+                }
+                else if (c == '[')
+                {
+                    throw new FormatException("encountered opening bracket in primary trailer");
+                }
+                else if (c == ']')
+                {
+                    throw new FormatException("encountered closing bracket in primary trailer");
+                }
+            }
+
+            string primaryTrailer = toParse.Length - start == 0 ? null : toParse.Substring(start);
+            return new Tag(primaryKey, primaryValue, primaryTrailer);
+        }
+
+        private static void ParseTag(string toParse, int start, ref List<Tag> tags)
+        {
+            for (int i = start; i < toParse.Length; i++)
+            {
+                char c = toParse[i];
+
+                if (c == '[')
+                {
+                    if (i == start)
+                        throw new FormatException("tag can't start with [");
+
+                    int j = ClosingBracketIndex(toParse, i + 1);
+                    ParseTrailer(toParse, j + 1, ref tags, toParse.Substring(start, i - start), toParse.Substring(i + 1, j - i - 1));
+                    return;
+                }
+                else if (c == ':')
+                {
+                    if (i == start)
+                        throw new FormatException("tag can't start with :");
+
+                    tags.Add(new Tag(toParse.Substring(start, i - start), null, null));
+                    ParseTag(toParse, i + 1, ref tags);
+                    return;
+                }
+                else if (c == ']')
+                {
+                    throw new FormatException("encountered closing bracket in key");
+                }
+            }
+
+            tags.Add(new Tag(toParse.Substring(start), null, null));
+        }
+
+        private static void ParseTrailer(string toParse, int start, ref List<Tag> tags, string key, string value)
+        {
+            for (int i = start; i < toParse.Length; i++)
+            {
+                char c = toParse[i];
+
+                if (c == ':')
+                {
+                    string trailer = i == start ? null : toParse.Substring(start, i - start);
+                    tags.Add(new Tag(key, value, trailer));
+                    ParseTag(toParse, i + 1, ref tags);
+                    return;
+                }
+                else if (c == '[')
+                {
+                    throw new FormatException("encountered opening bracket in trailer");
+                }
+                else if (c == ']')
+                {
+                    throw new FormatException("encountered closing bracket in trailer");
+                }
+            }
+
+            string finalTrailer = toParse.Length - start == 0 ? null : toParse.Substring(start);
+            tags.Add(new Tag(key, value, finalTrailer));
+        }
+
+        private static int ClosingBracketIndex(string toParse, int start)
+        {
+            int bracketLevel = 0;
+
+            for (int i = start; i < toParse.Length; i++)
+            {
+                char c = toParse[i];
+
+                if (c == '[')
+                {
+                    bracketLevel++;
+                }
+                else if (c == ']')
+                {
+                    bracketLevel--;
+                }
+
+                if (bracketLevel == -1) return i;
+            }
+
+            throw new FormatException("reached end of the tag list without encountering a close bracket");
+        }
+    }
+}
diff --git a/ModuleManagerTests/ModuleManagerTests.csproj b/ModuleManagerTests/ModuleManagerTests.csproj
@@ -79,6 +79,9 @@
     <Compile Include="PatchExtractorTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Progress\PatchProgressTest.cs" />
+    <Compile Include="Tags\TagListParserTest.cs" />
+    <Compile Include="Tags\TagListTest.cs" />
+    <Compile Include="Tags\TagTest.cs" />
     <Compile Include="Threading\TaskStatusTest.cs" />
     <Compile Include="Threading\BackgroundTaskTest.cs" />
     <Compile Include="Utils\CounterTest.cs" />