Between

between returns the part of a string found between two markers.

Overview

Use between to extract text enclosed by an opening and closing marker:

message | "Welcome, [Amanda]!"
name | message.between("[", "]")

:say(name)  /// Amanda

message | "Welcome, [Amanda]!"
name | message.between("[", "]")

:say(name)  /// Amanda

The markers themselves are not included in the result.

Method Style

Call between as a method on the string you want to search:

record | "order: {A-1842}"
order_number | record.between("{", "}")

:say(order_number)  /// A-1842

record | "order: {A-1842}"
order_number | record.between("{", "}")

:say(order_number)  /// A-1842

The equivalent free-call form is:

order_number | between("order: {A-1842}", "{", "}")

order_number | between("order: {A-1842}", "{", "}")

Both forms behave the same way.

First Matching Pair

between uses the first left marker and then the first right marker that appears after it:

text | "[north] and [south]"

text.between("[", "]")  /// north

text | "[north] and [south]"

text.between("[", "]")  /// north

It returns one string, not every enclosed section.

Multi-Character Markers

The markers may contain more than one character:

template | "Hello, {{customer_name}}!"
field | template.between("{{", "}}")

:say(field)  /// customer_name

template | "Hello, {{customer_name}}!"
field | template.between("{{", "}}")

:say(field)  /// customer_name

Missing Markers

If the left marker is missing, between returns an empty string:

between("Welcome, Amanda!", "[", "]")  /// ""

between("Welcome, Amanda!", "[", "]")  /// ""

If the left marker is found but no right marker follows it, the result is also an empty string:

between("Welcome, [Amanda!", "[", "]")  /// ""

between("Welcome, [Amanda!", "[", "]")  /// ""

Marker Order

The right marker must appear after the selected left marker. An earlier right marker is ignored:

between("] old [new]", "[", "]")  /// new

between("] old [new]", "[", "]")  /// new

Signature

string.between(left, right)
between(string, left, right)

string.between(left, right)
between(string, left, right)

between returns a string.

Errors

between requires a string and two markers:

between("Welcome, [Amanda]!", "[")
/// error: R0301 wrong-arity

between("Welcome, [Amanda]!", "[")
/// error: R0301 wrong-arity

All three values must be strings:

between("Chapter 12", "Chapter ", 20)
/// error: T0205 type-mismatch

between("Chapter 12", "Chapter ", 20)
/// error: T0205 type-mismatch