Commit 04b7cec42e

@@ -0,0 +1,132 @@
+const std = @import("std");
+const expect = std.testing.expect;
+
+pub const Source = struct {
+    buffer: []const u8,
+    file_name: []const u8,
+};
+
+pub const Token = struct {
+    id: Id,
+    num_suffix: NumSuffix = .None,
+    start: usize,
+    end: usize,
+    source: *Source,
+
+    pub const Id = enum {
+        Invalid,
+        Eof,
+        Nl,
+        Identifier,
+        StringLiteral,
+        CharLiteral,
+        IntegerLiteral,
+        FloatLiteral,
+        Bang,
+        BangEqual,
+        Pipe,
+        PipePipe,
+        PipeEqual,
+        Equal,
+        EqualEqual,
+        EqualAngleBracketRight,
+        LParen,
+        RParen,
+        LBrace,
+        RBrace,
+        LBracket,
+        RBracket,
+        Period,
+        PeriodAsterisk,
+        Ellipsis,
+        Caret,
+        CaretEqual,
+        Plus,
+        PlusPlus,
+        PlusEqual,
+        Minus,
+        MinusMinus,
+        MinusEqual,
+        Asterisk,
+        AsteriskEqual,
+        Percent,
+        PercentEqual,
+        Arrow,
+        Colon,
+        Semicolon,
+        Slash,
+        SlashEqual,
+        Comma,
+        Ampersand,
+        AmpersandAmpersand,
+        AmpersandEqual,
+        QuestionMark,
+        AngleBracketLeft,
+        AngleBracketLeftEqual,
+        AngleBracketAngleBracketLeft,
+        AngleBracketAngleBracketLeftEqual,
+        AngleBracketRight,
+        AngleBracketRightEqual,
+        AngleBracketAngleBracketRight,
+        AngleBracketAngleBracketRightEqual,
+        Tilde,
+        LineComment,
+        MultiLineComment,
+        Hash,
+        HashHash,
+    };
+
+    pub const NumSuffix = enum {
+        None,
+        F,
+        L,
+        U,
+        LU,
+        LL,
+        LLU,
+    };
+};
+
+pub const Tokenizer = struct {
+    source: *Source,
+    index: usize = 0,
+
+    pub fn next(self: *Tokenizer) Token {
+        const start_index = self.index;
+        var result = Token{
+            .id = .Eof,
+            .start = self.index,
+            .end = undefined,
+            .source = self.source,
+        };
+        var state: enum {
+            Start,
+        } = .Start;
+        while (self.index < self.source.buffer.len) : (self.index += 1) {
+            const c = self.source.buffer[self.index];
+            switch (state) {
+                .Start => switch (c) {
+                    else => @panic("TODO"),
+                },
+                else => @panic("TODO"),
+            }
+        }
+    }
+};
+
+fn expectTokens(source: []const u8, expected_tokens: []const Token.Id) void {
+    var tokenizer = Tokenizer{
+        .source = .{
+            .buffer = source,
+            .file_name = undefined,
+        },
+    };
+    for (expected_tokens) |expected_token_id| {
+        const token = tokenizer.next();
+        if (token.id != expected_token_id) {
+            std.debug.panic("expected {}, found {}\n", .{ @tagName(expected_token_id), @tagName(token.id) });
+        }
+    }
+    const last_token = tokenizer.next();
+    std.testing.expect(last_token.id == .Eof);
+}