break.md

Exit Block (break)

Terminate execution of a block within your processes scope

Description

break will terminate execution of a block (eg function, private, foreach, if, etc).

break requires a parameter and that parameter is the name of the caller block you wish to break out of. If it is a function or private, then it will be the name of that function or private. If it is an if or foreach loop, then it will be if or foreach (respectively).

Usage

break block-name

Examples

Exiting an iteration block

function foo {
    %[1..10] -> foreach i {
        out $i
        if { $i == 5 } then {
            out "exit running function"
            break foo
            out "ended"
        }
    }
}

Running the above code would output:

» foo
1
2
3
4
5
exit running function

Exiting a function

break can be considered to exhibit the behavior of return (from other languages) too

function example {
    if { $USER == "root" } then {
        err "Don't run this as root"
        break example
    }
    
    # ... do something ...
}

Though in this particular use case it is recommended that you use return instead, the above code does illustrate how break behaves.

Detail

break cannot escape the bounds of its scope (typically the function it is running inside). For example, in the following code we are calling break bar (which is a different function) inside of the function foo:

function foo {
    %[1..10] -> foreach i {
        out $i
        if { $i == 5 } then {
            out "exit running function"
            break bar
            out "ended"
        }
    }
}

function bar {
    foo
}

Regardless of whether we run foo or bar, both of those functions will raise the following error:

Error in `break` (7,17): no block found named `bar` within the scope of `foo`

See Also

• Exit Function (return): Exits current function scope
• Exit Murex (exit): Exit murex
• For Each In List (foreach): Iterate through an array
• For Each In Map (formap): Iterate through a map or other collection of data
• If Conditional (if): Conditional statement to execute different blocks of code depending on the result of the condition
• Next Iteration (continue): Terminate process of a block within a caller function
• Output String (out): Print a string to the stdout with a trailing new line character
• Private Function (private): Define a private function block
• Public Function (function): Define a function block

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This document was generated from builtins/core/structs/break_doc.yaml.