simplify-range

Simplify range statements and remove allocations that do not change the yielded values.

Default severity: warning

Behavior

The rule omits explicit blank range values and reports range []rune(text) when the index is discarded. Ranging directly over the string yields the same runes without allocating a slice. When the index is used, the conversion is preserved because a string range yields byte offsets while a rune-slice range yields rune indexes.

Bad

for _, character := range []rune(text) {
  use(character)
}

for _, _ = range values {
  use(values)
}

Good

for _, character := range text {
  use(character)
}

for range values {
  use(values)
}