Strings Module Documentation

The strings module provides string manipulation utilities that complement Neutron's built-in string operators.

Usage

use strings;

var parts = strings.split("a,b,c", ",");  // ["a", "b", "c"]
var upper = strings.upper("hello");        // "HELLO"
var trimmed = strings.trim("  hi  ");      // "hi"

Functions

Splitting & Joining

strings.split(str, delim?)

Splits str by delim (default " "). If delim is "", splits into individual characters.

strings.split("a,b,c", ",");   // ["a", "b", "c"]
strings.split("hello", "");    // ["h","e","l","l","o"]
strings.split("a b c");        // ["a", "b", "c"]

strings.join(array, delim?)

Joins array elements into a string. Default delimiter is "".

strings.join(["a", "b", "c"], ", ");  // "a, b, c"
strings.join(["x", "y"]);             // "xy"

---

Case

strings.upper(str) / strings.lower(str)

strings.upper("hello");  // "HELLO"
strings.lower("WORLD");  // "world"

---

Trimming

strings.trim(str)

Removes leading and trailing whitespace (space, \t, \r, \n).

strings.trim_left(str) / strings.trim_right(str)

One-sided trim.

strings.trim("  hi  ");        // "hi"
strings.trim_left("  hi  ");   // "hi  "
strings.trim_right("  hi  ");  // "  hi"

---

Searching

strings.contains(str, substr) → bool

strings.starts_with(str, prefix) → bool

strings.ends_with(str, suffix) → bool

strings.contains("hello world", "world");   // true
strings.starts_with("hello", "hel");        // true
strings.ends_with("hello", "llo");          // true

strings.index_of(str, substr, start?) → number

Returns the index of the first occurrence, or -1 if not found. Optional start offset.

strings.last_index_of(str, substr) → number

Returns the index of the last occurrence, or -1.

strings.index_of("abcabc", "bc");     // 1
strings.last_index_of("abcabc", "bc"); // 4
strings.index_of("hello", "x");       // -1

---

Replacing

strings.replace(str, from, to) → string

Replaces all occurrences of from with to.

strings.replace_first(str, from, to) → string

Replaces only the first occurrence.

strings.replace("aabbaa", "a", "x");        // "xxbbxx"
strings.replace_first("aabbaa", "a", "x");  // "xabbaa"

---

Slicing

strings.substring(str, start, end?) → string

Returns characters from start (inclusive) to end (exclusive). Defaults to end of string.

strings.substring("hello", 1, 3);  // "el"
strings.substring("hello", 2);     // "llo"

---

Utility

strings.length(str) → number

Returns byte length of the string.

strings.count(str, substr) → number

Counts non-overlapping occurrences of substr.

strings.count("banana", "an");  // 2

strings.repeat(str, n) → string

strings.repeat("ab", 3);  // "ababab"

strings.reverse(str) → string

strings.reverse("hello");  // "olleh"

---

Character Operations

strings.char_at(str, index) → string

Returns the character at index as a single-character string.

strings.char_code(str, index?) → number

Returns the ASCII code of the character at index (default 0).

strings.from_char_code(code) → string

Returns a single-character string for the given ASCII code (0–127).

strings.char_at("hello", 1);      // "e"
strings.char_code("A");           // 65
strings.from_char_code(65);       // "A"

---

Type Checks

strings.is_empty(str) → bool

strings.is_alpha(str) → bool — all alphabetic characters

strings.is_digit(str) → bool — all digit characters

strings.is_alnum(str) → bool — all alphanumeric characters

strings.is_empty("");       // true
strings.is_digit("123");    // true
strings.is_alpha("abc");    // true
strings.is_alnum("abc123"); // true

---

Examples

use strings;

// CSV row parser
fun parse_csv(line) {
    return strings.split(line, ",");
}

// Title case
fun title_case(s) {
    var words = strings.split(s, " ");
    var i = 0;
    while (i < words.length) {
        var w = words[i];
        if (w.length > 0) {
            words[i] = strings.upper(strings.substring(w, 0, 1))
                     + strings.lower(strings.substring(w, 1));
        }
        i = i + 1;
    }
    return strings.join(words, " ");
}

// Slug generator
fun slugify(s) {
    return strings.replace(strings.lower(strings.trim(s)), " ", "-");
}