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Variable And Config Scoping

How scoping works within Murex

Description

A scope in Murex is a collection of code blocks to which variables and config are persistent within. In Murex, a variable declared inside an if or foreach block will be persistent outside of their blocks as long as you’re still inside the same function.

For example lets start with the following function that sets a variable called foo

function example {
    if { true } then { set foo=bar }
    out $foo
}

In here the value is getting set inside an if block but its value is is retrieved outside of that block. out and set have different parents but the same scoping.

Then lets set foo outside of that function and see what happens:

» set foo=oof
» $foo
oof

» example
bar

» $foo
oof

Despite setting a variable named foo, the value inside example does not overwrite the value outside example because they occupy different scoping.

What Instantiates A New Scope?

A new scope is instantiated by anything which resembles a function. This would be code inside events, dynamic autocompletes, open agents, any code blocks defined in config, as well as public and private functions too.

Code inside an if, switch, foreach and source do not create a new scope. Sub-shells also do not create a new scope either.

See Also

• Define Handlers For “open” (openagent): Creates a handler function for open
• Define Variable (set): Define a variable (typically local) and set it’s value
• For Each In List (foreach): Iterate through an array
• If Conditional (if): Conditional statement to execute different blocks of code depending on the result of the condition
• Include / Evaluate Murex Code (source): Import Murex code from another file or code block
• Murex Event Subsystem (event): Event driven programming for shell scripts
• Private Function (private): Define a private function block
• Public Function (function): Define a function block
• Reserved Variables: Special variables reserved by Murex
• Shell Configuration And Settings (config): Query or define Murex runtime settings
• Switch Conditional (switch): Blocks of cascading conditionals
• Tab Autocompletion (autocomplete): Set definitions for tab-completion in the command line
• let: Evaluate a mathematical function and assign to variable (deprecated)

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This document was generated from gen/user-guide/scoping_doc.yaml.