Refactoring Rendering backend

2025-10-05 16:26:37 +09:00
parent a39f377533
commit 01a850ff94
99 changed files with 5056 additions and 5136 deletions
--- a/Ghost.Shader/Lexer.cs
+++ b/Ghost.Shader/Lexer.cs
@@ -0,0 +1,148 @@
+namespace Ghost.Shader;
+
+public class Lexer
+{
+    private readonly string _source;
+    private int _pos = 0;
+    private int _line = 0;
+    private int _column = 0;
+
+    public Lexer(string source) => _source = source;
+
+    public IEnumerable<Token> Tokenize()
+    {
+        while (_pos < _source.Length)
+        {
+            var c = _source[_pos];
+
+            // Skip whitespace
+            if (char.IsWhiteSpace(c))
+            {
+                if (c == '\n')
+                {
+                    _line++;
+                    _column = 0;
+                }
+                else
+                {
+                    _column++;
+                }
+
+                _pos++;
+                continue;
+            }
+
+            // Punctuation
+            switch (c)
+            {
+                case '=':
+                    yield return MakeToken(TokenType.Equals, "=");
+                    break;
+                case ';':
+                    yield return MakeToken(TokenType.Semicolon, ";");
+                    break;
+                case ',':
+                    yield return MakeToken(TokenType.Comma, ",");
+                    break;
+                case '{':
+                    yield return MakeToken(TokenType.LBrace, "{");
+                    break;
+                case '}':
+                    yield return MakeToken(TokenType.RBrace, "}");
+                    break;
+                case '(':
+                    yield return MakeToken(TokenType.LParen, "(");
+                    break;
+                case ')':
+                    yield return MakeToken(TokenType.RParen, ")");
+                    break;
+                case '"':
+                    yield return ReadString();
+                    break;
+                default:
+                    if (char.IsLetter(c) || c == '_')
+                    {
+                        yield return ReadIdentifierOrKeyword();
+                    }
+                    else if (char.IsDigit(c) || c == '.')
+                    {
+                        yield return ReadNumber();
+                    }
+                    else
+                    {
+                        _pos++; // skip unknown
+                    }
+                    break;
+            }
+        }
+
+        yield return new Token(TokenType.EndOfFile, "", _line, _column);
+    }
+
+    private Token MakeToken(TokenType type, string lexeme)
+    {
+        var token = new Token(type, lexeme, _line, _column);
+        _pos++;
+        _column++;
+        return token;
+    }
+
+    private Token ReadString()
+    {
+        var startCol = _column;
+
+        _pos++;
+        _column++; // skip "
+
+        var start = _pos;
+        while (_pos < _source.Length && _source[_pos] != '"')
+        {
+            _pos++;
+            _column++;
+        }
+
+        var text = _source.Substring(start, _pos - start);
+
+        _pos++;
+        _column++; // skip closing "
+
+        return new Token(TokenType.StringLiteral, text, _line, startCol);
+    }
+
+    private Token ReadIdentifierOrKeyword()
+    {
+        var startCol = _column;
+        var start = _pos;
+
+        while (_pos < _source.Length && (char.IsLetterOrDigit(_source[_pos]) || _source[_pos] == '_'))
+        {
+            _pos++;
+            _column++;
+        }
+
+        var text = _source.Substring(start, _pos - start);
+
+        // Optional: detect keywords
+        if (TokenLexicon.IsKeyword(text))
+        {
+            return new Token(TokenType.Keyword, text, _line, startCol);
+        }
+
+        return new Token(TokenType.Identifier, text, _line, startCol);
+    }
+
+    private Token ReadNumber()
+    {
+        var startCol = _column;
+        var start = _pos;
+
+        while (_pos < _source.Length && (char.IsDigit(_source[_pos]) || _source[_pos] == '.'))
+        {
+            _pos++;
+            _column++;
+        }
+
+        var num = _source.Substring(start, _pos - start);
+        return new Token(TokenType.Number, num, _line, startCol);
+    }
+}