Add translator from poyo

PoyoLang.Test/Program.cs

@@ -7,8 +7,19 @@ Console.OutputEncoding = Encoding.UTF8;
 
 var text = "Immutable abstract representation of a span of text. For example, in an error diagnostic that reports a location, it could come from a parsed string, text from a tool editor buffer, etc.";
 
+Console.WriteLine("Original:");
+Console.WriteLine(text);
+Console.WriteLine();
+
 var translator = new PoyoLangTranslator();
 
 var translated = translator.TranslateToPoyo(text);
 
-Console.WriteLine(translated);
+Console.WriteLine("Translated to Poyo:");
+Console.WriteLine(translated);
+Console.WriteLine();
+
+var original = translator.TranslateFromPoyo(translated);
+
+Console.WriteLine("Translated back from Poyo:");
+Console.WriteLine(original);

PoyoLang.Translator.SourceGenerator/PoyoLangTranslatorGenerator.cs

@@ -26,16 +26,22 @@ public class PoyoLangTranslatorGenerator : IIncrementalGenerator
         var formattedDictionaries = parsedDictionaries
             .Select(static (dictionary, _) =>
             {
-                // Reverse dictionary order to have ngrams first
-                return dictionary!.OrderBy(p => p.Value).ToDictionary(p => p.Value, p => p.Key);
+                // Return normal and reverse dictionary order to have ngrams first
+                return (
+                    Normal: dictionary,
+                    Reversed: dictionary!.OrderBy(p => p.Value).ToDictionary(p => p.Value, p => p.Key)
+                );
             });
 
         var prefixTrees = formattedDictionaries
-            .Select(static (formattedDictionary, _) => BuildPrefixTree(formattedDictionary));
+            .Select(static (dictionaries, _) => (
+                Dictionary: dictionaries.Normal,
+                PrefixTree: BuildPrefixTree(dictionaries.Reversed)
+            ));
 
-        context.RegisterSourceOutput(prefixTrees, static (sourceProductionContext, prefixTree) =>
+        context.RegisterSourceOutput(prefixTrees, static (sourceProductionContext, data) =>
         {
-            sourceProductionContext.AddSource("PoyoLangTranslator.g.cs", GenerateSource(prefixTree));
+            sourceProductionContext.AddSource("PoyoLangTranslator.g.cs", GenerateSource(data.Dictionary, data.PrefixTree));
         });
     }
 
@@ -103,7 +109,7 @@ public class PoyoLangTranslatorGenerator : IIncrementalGenerator
         }
     }
 
-    private static string GenerateSource(List<Node> rootNodes)
+    private static string GenerateSource(Dictionary<string, string> dictionary, List<Node> rootNodes)
     {
         var source = new StringBuilder();
 
@@ -128,43 +134,9 @@ public class PoyoLangTranslatorGenerator : IIncrementalGenerator
             """
         );
 
-        // Next letter method definition
-        source.Append(
-            """
-                private void NextLetter(ref ReadOnlySpan<char> text, StringBuilder output)
-                {
-            
-            """
-        );
+        GenerateNextLetterMethod(rootNodes, source);
 
-        // 0 length case and caps
-        source.Append(
-            """
-                    if (text.Length < 1)
-                    {
-                        return;
-                    }
-            
-                    var isCaps = char.IsUpper(text[0]);
-            
-            
-            """
-        );
-
-        GenerateSwitchCases(rootNodes, depth: 0, source: source);
-
-        // Next letter method end
-        source.Append(
-            """
-            
-                    // Punctuation/Unknown characters case
-                    output.Append(text[0]);
-            
-                    text = text[1..];
-                }
-            
-            """
-        );
+        GenerateFromPoyoMethod(dictionary, source);
 
         // Partial class end
         source.Append(
@@ -176,78 +148,224 @@ public class PoyoLangTranslatorGenerator : IIncrementalGenerator
         return source.ToString();
     }
 
-    private static void GenerateSwitchCases(List<Node> nodes, int depth, StringBuilder source)
+    private static void GenerateNextLetterMethod(List<Node> rootNodes, StringBuilder source)
     {
-        var indent = Indent(depth * 3);
-
-        // Switch-case start
+        // Next letter method definition
         source.Append(
-            $$"""
-                    {{indent}}switch (text[{{depth}}])
-                    {{indent}}{
+            """
+                private void NextLetter(ref ReadOnlySpan<char> text, StringBuilder output)
+                {
+
+            """
+        );
+
+        // 0 length case and caps
+        source.Append(
+            """
+                    if (text.Length < 1)
+                    {
+                        return;
+                    }
+
+                    var isCaps = char.IsUpper(text[0]);
 
 
             """
         );
 
-        foreach (var node in nodes)
-        {
-            var targetLower = node.Target;
-            var targetUpper = ToTitleCase(targetLower);
+        GenerateSwitchCases(rootNodes, depth: 0);
 
-            // Case start
+        // Next letter method end
+        source.Append(
+            """
+
+                    // Punctuation/Unknown characters case
+                    output.Append(text[0]);
+
+                    text = text[1..];
+                }
+
+            """
+        );
+
+        return;
+
+        void GenerateSwitchCases(List<Node> nodes, int depth)
+        {
+            var indent = Indent(depth * 3);
+
+            // Switch-case start
             source.Append(
                 $$"""
-                          {{indent}}    case '{{node.Letter}}' or '{{char.ToUpper(node.Letter)}}':
+                          {{indent}}switch (text[{{depth}}])
+                          {{indent}}{
 
 
                   """
             );
 
-            // Sub nodes handling
-            if (node.Nodes.Count > 0)
+            foreach (var node in nodes)
             {
+                var targetLower = node.Target;
+                var targetUpper = ToTitleCase(targetLower);
+
+                // Case start
                 source.Append(
                     $$"""
-                              {{indent}}        if (text.Length > {{depth + 1}})
-                              {{indent}}        {
+                              {{indent}}    case '{{node.Letter}}' or '{{char.ToUpper(node.Letter)}}':
+
 
                       """
                 );
 
-                // Sub nodes
-                GenerateSwitchCases(node.Nodes, depth + 1, source);
+                // Sub nodes handling
+                if (node.Nodes.Count > 0)
+                {
+                    source.Append(
+                        $$"""
+                                  {{indent}}        if (text.Length > {{depth + 1}})
+                                  {{indent}}        {
 
+                          """
+                    );
+
+                    // Sub nodes
+                    GenerateSwitchCases(node.Nodes, depth + 1);
+
+                    source.Append(
+                        $$"""
+                                  {{indent}}        }
+
+                          """
+                    );
+                }
+
+                // Current node handling fallback
                 source.Append(
                     $$"""
-                              {{indent}}        }
+                              {{indent}}
+                              {{indent}}        text = text[{{depth + 1}}..];
+                              {{indent}}
+                              {{indent}}        output.Append(isCaps ?  "{{targetUpper}}" : "{{targetLower}}");
+                              {{indent}}
+                              {{indent}}        return;
+
 
                       """
                 );
             }
 
-            // Current node handling fallback
+            // Switch-case end
             source.Append(
                 $$"""
-                          {{indent}}
-                          {{indent}}        text = text[{{depth + 1}}..];
-                          {{indent}}
-                          {{indent}}        output.Append(isCaps ?  "{{targetUpper}}" : "{{targetLower}}");
-                          {{indent}}
-                          {{indent}}        return;
-
+                          {{indent}}}
 
                   """
             );
         }
+    }
 
-        // Switch-case end
+    private static void GenerateFromPoyoMethod(Dictionary<string, string> dictionary, StringBuilder source)
+    {
+        // From Poyo method definition
         source.Append(
-            $$"""
-                      {{indent}}}
+            """
+            
+                private void FromPoyo(ref ReadOnlySpan<char> text, StringBuilder output)
+                {
 
-              """
+            """
         );
+
+        // Initial cases
+        source.Append(
+            """
+                    if (text.Length < 1)
+                    {
+                        return;
+                    }
+                    
+                    // This happens if the end of the text is not a poyo letter (punctuation for ex)
+                    if (text.Length < 4)
+                    {
+                        output.Append(text);
+                        
+                        text = text[^0..];
+                    
+                        return;
+                    }
+                    
+                    var letter = text[..4];
+
+
+            """
+        );
+
+        GenerateReverseSwitchCases();
+
+        // From Poyo method end
+        source.Append(
+            """
+
+                    // Advance in text
+                    text = text[4..];
+                }
+
+            """
+        );
+
+        return;
+
+        void GenerateReverseSwitchCases()
+        {
+            // Switch start
+            source.Append(
+                """
+                        switch (letter)
+                        {
+
+                """
+            );
+
+            foreach (var pair in dictionary)
+            {
+                // Non-caps case
+                source.Append(
+                    $$"""
+                                case "{{pair.Key}}":
+                                    output.Append("{{pair.Value}}");
+                                    break;
+
+                    """
+                );
+
+                // Caps case
+                source.Append(
+                    $$"""
+                                  case "{{ToTitleCase(pair.Key)}}":
+                                      output.Append("{{ToTitleCase(pair.Value)}}");
+                                      break;
+
+
+                      """
+                );
+            }
+
+            // Switch end
+            source.Append(
+                """
+                            default:
+                                // Not a poyo letter, only read 1 character (could be punctuation for ex)
+                                output.Append(text[0]);
+                                
+                                text = text[1..];
+                                
+                                return;
+                        }
+
+                """
+            );
+        }
     }
 
     private static string ToTitleCase(string text)

PoyoLang.Translator/PoyoLangTranslator.cs

@@ -21,4 +21,19 @@ public partial class PoyoLangTranslator
 
         return output.ToString();
     }
+
+    public string TranslateFromPoyo(ReadOnlySpan<char> text)
+    {
+        var output = new StringBuilder(text.Length);
+
+        while (text.Length > 0)
+        {
+            // Skip spaces (those are not used in this language)
+            text = text.TrimStart(' ');
+
+            FromPoyo(ref text, output);
+        }
+
+        return output.ToString();
+    }
 }