The q* stdlib docs

qstring: string operations

qstring exposes the string.* built-ins: case conversion, trimming, reversal, and a character count. They take the string as the first positional argument and return either a string or an integer under the result key. A useful convenience is implicit numeric coercion — if you pass a number where a string is expected, it is stringified first, so string.upper(7) and string.len(123) just work.

What it gives you#

qstring registers five public built-ins, all following the shared DMS convention and callable inline from QQL.

Function	Returns	Behavior
string.upper	Str	Uppercases the input (Unicode-aware to_uppercase).
string.lower	Str	Lowercases the input (Unicode-aware to_lowercase).
string.trim	Str	Removes leading and trailing whitespace.
string.reverse	Str	Reverses the string by Unicode scalar (char) order.
string.len	Int	Character count — number of chars, not bytes.

Input coercion#

The first positional argument is read as a string. A Str is used directly. An Int or Float is converted to its textual form first (for example 7 becomes "7", 1.5 becomes "1.5"). Any other type, or a missing argument, is treated as the empty string.

Resource budget#

These operations allocate proportionally to the input string: upper/lower/reverse/trim decode one copy and build another, and case folding can grow the string. Each string.* function declares a fixed 4096-byte (4 KB) memory budget and zero storage.

Example#

string.len returns the character count of its argument.

Request

string.len("hello")

# wire form:
{ "0": { "Str": "hello" } }

Response

{ "result": { "Int": 5 } }

Output

Request

string.upper("ab")
string.reverse("abc")
string.upper(7)

Response

{ "result": { "Str": "AB" } }
{ "result": { "Str": "cba" } }
{ "result": { "Str": "7" } }

Output

AB
cba
7