src/scanner.zig

@@ -116,16 +116,10 @@ pub const Scanner = struct {
         };
     }
 
-    fn makeTokenLexeme(
-        self: *Scanner,
-        ttype: TokenType,
-        lexeme: []const u8,
-    ) Token {
-        return Token{
-            .ttype = ttype,
-            .lexeme = lexeme,
-            .line = self.line,
-        };
+    fn makeTokenAdvance(self: *Scanner, ttype: TokenType) Token {
+        var tok = self.makeToken(ttype);
+        self.current += 1;
+        return tok;
     }
 
     /// Check if the next character matches what is expected.
@@ -204,48 +198,6 @@ pub const Scanner = struct {
         return self.makeToken(ttype);
     }
 
-    /// Consume a string. stop_char is used to determine
-    /// if the string is a single quote or double quote string
-    fn doString(self: *Scanner, stop_char: u8) !Token {
-        // consume entire string
-        while (self.peekNext() != stop_char and !self.isAtEnd()) {
-            if (self.peek() == '\n') self.line += 1;
-            _ = self.advance();
-        }
-
-        // unterminated string.
-        if (self.isAtEnd()) {
-            return ScannerError.Unterminated;
-        }
-
-        // the closing character of the string
-        _ = self.advance();
-
-        // remove the starting and ending chars of the string
-        const lexeme = self.currentLexeme();
-        return self.makeTokenLexeme(
-            .String,
-            lexeme[1 .. lexeme.len - 1],
-        );
-    }
-
-    fn makeTripleMatchToken(
-        self: *Scanner,
-        char1: u8,
-        ttype1: TokenType,
-        char2,
-        ttype2: TokenType,
-        fallback: TokenType,
-    ) Token {
-        if (self.match(char1)) {
-            return self.makeToken(ttype1);
-        } else if (self.match(char2)) {
-            return self.makeToken(ttype2);
-        } else {
-            return self.makeToken(fallback);
-        }
-    }
-
     pub fn nextToken(self: *Scanner) !?Token {
         self.skipWhitespace();
         self.start = self.current;
@@ -272,14 +224,26 @@ pub const Scanner = struct {
             '$' => self.makeToken(.DollarSign),
 
             '-' => self.makeToken(.Minus),
+            '+' => self.makeToken(.Plus),
             '*' => self.makeToken(.Star),
-            '%' => self.makeToken(.Modulo),
 
             '!' => self.makeMatchToken('=', .BangEqual, .Bang),
             '=' => self.makeMatchToken('=', .EqualEqual, .Equal),
+
+            // there can be three tokens from a <
+            //  - <, which is LessThan
+            //  - <=, which is LessEqual
+            //  - <<, which is LeftDoubleChevron
+            '<' => blk: {
+                if (self.match('=')) {
+                    break :blk self.makeToken(.LessEqual);
+                } else if (self.match('<')) {
+                    break :blk self.makeToken(.LeftDoubleChevron);
+                } else {
+                    break :blk self.makeToken(.Less);
+                }
+            },
             '>' => self.makeMatchToken('=', .GreaterEqual, .Greater),
-            '+' => self.makeTripleMatchToken('+', .PlusPlus, '=', .PlusEqual, .Plus),
-            '<' => self.makeTripleMatchToken('=', .LessEqual, '<', .LeftDoubleChevron, .Less),
 
             '/' => blk: {
                 var next = self.peekNext();
@@ -306,9 +270,6 @@ pub const Scanner = struct {
                 }
             },
 
-            '\'' => try self.doString('\''),
-            '"' => try self.doString('"'),
-
             else => return ScannerError.Unexpected,
         };