1 files changed, 28 insertions, 21 deletions
diff --git a/src/lexer.zig b/src/lexer.zig
index 93ed6cc..67beec9 100644
--- a/src/lexer.zig
+++ b/src/lexer.zig
@@ -1,49 +1,56 @@
 pub const Token = struct {
-    start: usize,
-    end: usize,
+    loc: Location,
     type: Type,
 
     pub const Type = union(enum) {
-        LeftParen,
-        RightParen,
-        IntegerLiteral: usize,
-        Plus,
-        Invalid,
-        Eof,
+        left_paren,
+        right_paren,
+        integer_literal,
+        plus,
+        invalid,
+        eof,
     };
 };
 
+pub const Location = struct {
+    start: usize,
+    end: usize,
+
+    pub fn combine(a: Location, b: Location) Location {
+        if (a.end > b.start) unreachable;
+        return .{ .start = @min(a.start, b.start), .end = @max(a.end, b.end) };
+    }
+};
+
 source: []const u8,
 last_end: usize = 0,
 pos: usize = 0,
 
 pub fn next(self: *Self) ?Token {
-    return s: switch (self.eat() orelse return self.create(.Eof)) {
-        '(' => self.create(.LeftParen),
-        ')' => self.create(.RightParen),
-        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' => |d| self.integerLiteral(d),
-        '+' => self.create(.Plus),
+    return s: switch (self.eat() orelse return self.create(.eof)) {
+        '(' => self.create(.left_paren),
+        ')' => self.create(.right_paren),
+        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' => self.integerLiteral(),
+        '+' => self.create(.plus),
         ' ' => {
             self.last_end = self.pos;
-            continue :s (self.eat() orelse return self.create(.Eof));
+            continue :s (self.eat() orelse return self.create(.eof));
         },
-        else => self.create(.Invalid),
+        else => self.create(.invalid),
     };
 }
 
-fn integerLiteral(self: *Self, first: u8) Token {
-    var value: usize = @intCast(digitValue(first).?);
-    while (digitValue(self.peek())) |d| {
+fn integerLiteral(self: *Self) Token {
+    while (digitValue(self.peek()) != null) {
         _ = self.eat();
-        value = value *| 10 +| d;
     }
-    return self.create(.{ .IntegerLiteral = value });
+    return self.create(.{ .integer_literal = {} });
 }
 
 fn create(self: *Self, tajp: Token.Type) Token {
     const start = self.last_end;
     self.last_end = self.pos;
-    return .{ .start = start, .end = self.pos, .type = tajp };
+    return .{ .loc = .{ .start = start, .end = self.pos }, .type = tajp };
 }
 
 fn eat(self: *Self) ?u8 {