const std = @import("std");

pub fn isNameChar(char: u8) bool {
	return switch(char) {
		'0'...'9', 'A'...'Z', 'a'...'z', '_' => true,
		else => false
	};
}

pub fn read_name(buffer: []const u8) struct { []const u8, []const u8 } {
	for (buffer, 0..) |char, index| {
		if (!isNameChar(char)) {
			return .{ buffer[0..index], buffer[index..] };
		}
	}

	return .{ buffer[0..buffer.len], buffer[buffer.len..] };
}

pub fn read_first_from_literal(buffer: []const u8) !struct { u8, []const u8 } {
	if (buffer[0] != '\\') {
		return .{ buffer[0], buffer[1..] } ;
	}

	if (buffer.len > 1 and buffer[1] != 'x') {
		return switch(buffer[1]) {
			't' => return .{ '\t', buffer[2..] },
			'n' => return .{ '\n', buffer[2..] },
			'r' => return .{ '\r', buffer[2..] },
			'\'' => return .{ '\'', buffer[2..] },
			'\\' => return .{ '\\', buffer[2..] },
			else => return error.InvalidEscapeSequence,
		};
	}

	if (buffer.len > 4 and buffer[1] == 'x') {
		return .{ try std.fmt.parseInt(u8, buffer[2..4], 16), buffer[4..] };
	}

	return error.InvalidEscapeSequnce;
}