The `text` module provides string utility functions that complement the built-in `Str` methods.

```vary
from text import starts_with, pad_left, join

let ok = starts_with("hello", "hel")   # True
let id = pad_left("42", 5, "0")        # "00042"
let csv = join(["a", "b", "c"], ", ")   # "a, b, c"
```

## String testing

| **Function** | **Returns** | **Description** |
|----------|-----------|-----------|
| `is_empty(s)` | `Bool` | True if `len(s) == 0` |
| `is_blank(s)` | `Bool` | True if the string is empty or contains only whitespace |
| `starts_with(s, prefix)` | `Bool` | True if `s` begins with `prefix` |
| `ends_with(s, suffix)` | `Bool` | True if `s` ends with `suffix` |
| `contains(s, sub)` | `Bool` | True if `sub` appears anywhere in `s` |

```vary
from text import is_empty, is_blank, starts_with, ends_with, contains

print(is_empty(""))           # True
print(is_blank("  \n"))       # True
print(starts_with("vary", "va"))  # True
print(ends_with("file.txt", ".txt"))  # True
print(contains("hello world", "world"))  # True
```

## String transformation

| **Function** | **Returns** | **Description** |
|----------|-----------|-----------|
| `repeat(s, times)` | `Str` | Repeat `s` the given number of times |
| `pad_left(s, width, ch)` | `Str` | Pad `s` on the left with `ch` until it reaches `width` |
| `pad_right(s, width, ch)` | `Str` | Pad `s` on the right with `ch` until it reaches `width` |
| `join(items, separator)` | `Str` | Concatenate strings with `separator` between |
| `count_occurrences(s, sub)` | `Int` | Count non-overlapping occurrences of `sub` in `s` |
| `reverse_string(s)` | `Str` | Reverse the characters in a string |

```vary
from text import repeat, pad_left, pad_right, join, count_occurrences, reverse_string

let stars = repeat("*", 5)              # "*****"
let left = pad_left("7", 3, "0")        # "007"
let right = pad_right("hi", 5, ".")     # "hi..."
let csv = join(["x", "y", "z"], ", ")   # "x, y, z"
let n = count_occurrences("abcabc", "abc")  # 2
let rev = reverse_string("hello")       # "olleh"
```