x.y
module:f
a[i]
a[%i]
f(x)
x--
x++
| Member access
Module function or variable access
Subscript
N. Subscript ({…if i is negative, the index is relative to the end of the array})
Function call
Postfix decrement
Postfix increment |

^ | Power operator (right to left associative) |

-x
+x
!x
(-)x
--x
++x
&x
| Unary minus
Unary plus
Logical NOT
Bitwise NOT (rationale: {…
Operator (-) complements operator XOR (+) and has the following properties:
a(-)b = NOT (a XOR b)
NOT a = 0(-)a = (-)a
a(-)(-)b = a(+)b
a(+)(-)b = a(-)b
(-)(-)a = a
However, binary operator (-) is not supported in hardware and used extremely rare, therefore 11l includes only unary operator (-), which corresponds to bitwise NOT.
})
Prefix decrement
Prefix increment
Address-of |

x * y
x / y
x I/ y
x -I/ y
x % y
x -% y
| Multiplication
Division
Integer division {…note that -5 // 2 = -3 in Python whereas -5 I/ 2 = -2 in 11l, but this is merely because of performance considerations, and if you know efficient implementation of Python integer division, please write at the forum}
N. Integer division ({…performs floor division if dividend is negative})
Remainder
N. Remainder ({…result is positive even if x is negative}) |

x""y and x‘’y | String concatenation (rationale) |

x + y
x - y | Addition
Subtraction |

x << y
x >> y | Bitwise left shift
Bitwise right shift |

x [&] y | Bitwise AND (rationale: {…
[&] looks similar to AND gate:
}) |

x (+) y | Bitwise XOR (rationale: {…
Symbols (+) look like symbol ⊕, which is used in Boolean algebra for exclusive or operation: .
And although ⊕ is used more often for single-bit values, in Wikipedia it is sometimes used for pointers and for arrays of bytes. In addition, the symbol ⊕ can be found in scientific articles, as well as in problem texts on Codeforces (1, 2).
[Besides, usage of ^ for this operation I consider a bad idea (at least this is confusing for novices).]
}) |

x [|] y | Bitwise OR (rationale: {…
Symbol | looks like 1 and [1] looks similar to OR gate:
}) |

x < y, x <= y
x > y, x >= y | Comparison operators |

x ? y | Null coalescing |

x..y, x.<y, x.+len
x<.y, x<.<y | Ranges |

x == y, x != y
e in c, e !in c
e C c, e !C c
| Comparisons
Including membership tests |

x & y | Logical AND (rationale: {…
& is used instead of && because:
- Logical AND is needed much more often than bitwise AND.
- Bitwise AND is almost always used just for check if some flag is set, but this is error-prone {…
Consider following C++ code:
class Render
{
public:
static const unsigned F_CAST_SHADOWS = 1 << ...;
};
class Control
{
public:
unsigned flags;
static const unsigned F_DISABLED = 1 << ...;
};
void some_func(Control *c)
{
if (c->flags & Control::F_DISABLED) {
...
}
if (c->flags & Render::F_CAST_SHADOWS) { // this is wrong, but will be correctly compiled in C++!
...
}
}
11l solution:
T Control
T.flags flags
DISABLED
or:
T Control
T Flags
Bool DISABLED
Flags flags
F some_func(Control c)
I c.flags.DISABLED
...
}, so the decision was made to discourage from such usage of bitwise AND operator at all.
Sometimes bitwise AND is used as a modulo (% ) operation of powers of 2, but if the second operand is constant, then operator % should be used instead (x [&] y = x % (y + 1) ). If operator % works for negative numbers like in Python (i.e. e.g. -1 % 4 = 3 ), then expression x % (y + 1) will be compiled to bitwise AND.
There should not be any problem with converting code from C-like language to 11l, because in case you forget to replace & with [&] , then there will be a compile-time error as <number> & <number> is not valid in 11l (only <boolean> & <boolean> is valid, e.g. <number> != 0 & <number> != 0 ).
The symbol & is also used as logical AND in Oberon and ALGOL 68.
}) |

x | y | Logical OR |

arr1 [+] arr2 | Array concatenation (rationale: {…
Because arrays are defined using square brackets: [1, 2, ...] .
As this operation is quite expensive, it has dedicated operator.
}) |

() -> expr
x -> expr
(x, y) -> expr | Lambda expression |

x = ...
x += ...
-= *= /= I/=
%= >>= <<= ^=
[+]= [&]= [|]=
(+)= ‘’= .= | Assignments (right to left associative) |