reverse

Builtin index · Collections & strings

result = reverse(x)

Input: x · Output: result

What it is

x is a Str, List, Vec, or Mask. Unicode-aware character reversal for a Str (same type back); element-order reversal for a List/Vec/Mask (same type and shape back).

Overloads

One call shape — this function is not overloaded.

Examples

From the documentation, and run by the build -- the output and the figure below are what the engine actually produced. Simplest first.

s = "Hello, Qu World!"
print(mid(s, 7, 2))          # "Qu"

print(left(s, 5))            # "Hello"

print(right(s, 6))           # "World!"

print(reverse("abc"))        # "cba"

print(lower("SHOUT"))        # "shout"

print(ucase("shout"))        # "SHOUT"

print(lcase("SHOUT"))        # "shout"

print(toupper("mix"))        # "MIX"

print(tolower("MIX"))        # "mix"

print(capitalize("ada lovelace"))  # "Ada lovelace"

print(ltrim("   padded"))    # "padded"

print(rtrim("padded   ") + "|")   # "padded|"

print(pad_right("ab", 5, "."))    # "ab..."

print(compare("apple", "banana")) # -1

print(asc("A"))              # 65

Qu
Hello
World!
cba
shout
SHOUT
shout
MIX
mix
Ada lovelace
padded
padded|
ab...
-1
    ... 1 more lines

from collections-strings

How it works

reverse(x) — for a Str, the unicode-aware reversed string; for a List, element order reversed; for a Vec/ Mask, the same element-order reversal fliplr/mirror already provide under those names (verified equivalent to fliplr on a plain vector) — reverse is simply this codebase's first conventionally-named entry point that also covers Str/List, not a second, divergent algorithm for the numeric case.

From the note above this builtin in the interpreter, where the reasoning was written down as it was built.