feat: char literal

closes #172

CHANGELOG.md

@@ -24,6 +24,7 @@
     - `Buffer.readUserData`, `Buffer.writeUserData`
 - `std.serialize` takes any buzz value and return a serializable version of it (objects become maps, etc.) provided the data is has no circular reference and does not contain not serializable values (functions, fibers, etc.)
 - UTF8 helpers: `str.utf8Len`, `str.utf8Codepoints`, `str.utf8Valid`
+- New integer literal for single chars: `'A' == 65`
 
 ## Changed
 

src/lib/serialize.buzz

@@ -356,5 +356,9 @@ export fun jsonEncode(Boxed data) > str !> CircularReference, NotSerializable {
 || @param str json The JSON string
 || @return Boxed
 export fun jsonDecode(str json) > Boxed !> JsonParseError, WriteWhileReadingError {
-    return Boxed{ data = JsonParser{ source = json }.next() };
+    return Boxed{
+        data = JsonParser{
+            source = json
+        }.next()
+    };
 }

src/scanner.zig

@@ -121,6 +121,7 @@ pub const Scanner = struct {
             '=' => self.makeToken(if (self.match('=')) .EqualEqual else .Equal, null, null, null),
             '"' => self.string(false),
             '`' => self.string(true),
+            '\'' => self.byte(),
             '@' => self.atIdentifier(),
             '|' => self.docblock(),
             '$' => self.pattern(),
@@ -276,6 +277,42 @@ pub const Scanner = struct {
         );
     }
 
+    fn byte(self: *Self) Token {
+        const is_escape_sequence = self.match('\\');
+        const literal_integer = if (is_escape_sequence)
+            self.advance()
+        else
+            self.advance();
+
+        if (is_escape_sequence and literal_integer != '\\' and literal_integer != '\'') {
+            return self.makeToken(
+                .Error,
+                "Invalid escape sequence in char literal.",
+                null,
+                null,
+            );
+        }
+
+        // Skip closing
+        if (self.isEOF() or self.peek() != '\'') {
+            return self.makeToken(
+                .Error,
+                "Unterminated char literal.",
+                null,
+                null,
+            );
+        } else {
+            _ = self.advance();
+        }
+
+        return self.makeToken(
+            .IntegerValue,
+            null,
+            null,
+            @intCast(literal_integer),
+        );
+    }
+
     fn binary(self: *Self) !Token {
         var peeked: u8 = self.peek();
         while (peeked == '0' or peeked == '1') {

tests/001-basic-types.buzz

@@ -1,6 +1,22 @@
+import "std";
+
 test "Basic types" {
     str string = "hello world";
     float floating = 3.14;
     int integer = 3;
     bool boolean = true;
+}
+
+test "Char literal" {
+    int char = 'A';
+
+    assert(char == 65, message: "Could use char literal");
+
+    int quote = '\'';
+
+    assert(quote == 39, message: "Could escape ' in char literal");
+
+    int slash = '\\';
+
+    assert(slash == 92, message: "Could escape \\ in char literal");
 }