Operators

All Bop operators, grouped by category. No operator overloading — each operator works on specific types and produces an error on type mismatch.

Arithmetic

print(10 + 3)      // 13
print(10 - 3)      // 7
print(10 * 3)      // 30
print(10 / 3)      // 3.333...
print(10 % 3)      // 1

print("Hello" + " " + "world")    // "Hello world"

Comparison

== and != work on all types. Comparing different types is always false (no implicit coercion). <, >, <=, >= work on numbers and strings (lexicographic).

print(5 == 5)         // true
print(5 == "5")       // false (different types)
print("abc" < "def")  // true (lexicographic)

Boolean

Short-circuiting means the second operand isn’t evaluated if the first determines the result:

// && stops at the first false
if x > 0 && x < 100 {
  print("In range")
}

// || stops at the first true
if name == "" || name == none {
  print("No name provided")
}

// ! inverts a boolean
if !found {
  print("Still searching...")
}

Assignment

let score = 0
score += 10    // 10
score -= 3     // 7
score *= 2     // 14

Conditional expressions

Bop has no ternary operator (?:). Use if/else as an expression instead:

let label = if count > 3 { "lots" } else { "few" }

Both branches are required when if/else is used as an expression. The last expression in each branch is the value.

Precedence

From highest (evaluated first) to lowest:

Parentheses override precedence:

let result = (1 + 2) * 3    // 9, not 7