private

Define a private function block

Description

private defines a function who's scope is limited to that module or source file.

Privates cannot be called from one module to another (unless they're wrapped around a global function) and nor can they be called from the interactive command line. The purpose of a private is to reduce repeated code inside a module or source file without cluttering up the global namespace.

Usage

private: name { code-block }

Examples

# The following cannot be entered via the command line. You need to write
# it to a file and execute it from there.

private hw {
    out "Hello, World!"
}

function tom {
    hw
    out "My name is Tom."
}

function dick {
    hw
    out "My name is Dick."
}

function harry {
    hw
    out "My name is Harry."
}

Detail

Allowed characters

Private names can only include any characters apart from dollar ($). This is to prevent functions from overwriting variables (see the order of preference below).

Undefining a private

Because private functions are fixed to the source file that declares them, there isn't much point in undefining them. Thus at this point in time, it is not possible to do so.

Order of preference

There is an order of precedence for which commands are looked up:

1. runmode: this is executed before the rest of the script. It is invoked by the pre-compiler forking process and is required to sit at the top of any scripts.

2. test and pipe functions also alter the behavior of the compiler and thus are executed ahead of any scripts.

3. private functions - defined via private. Private's cannot be global and are scoped only to the module or source that defined them. For example, You cannot call a private function directly from the interactive command line (however you can force an indirect call via fexec).

4. Aliases - defined via alias. All aliases are global.

5. Murex functions - defined via function. All functions are global.

6. Variables (dollar prefixed) which are declared via global, set or let. Also environmental variables too, declared via export.

7. globbing: however this only applies for commands executed in the interactive shell.

8. Murex builtins.

9. External executable files

You can override this order of precedence via the fexec and exec builtins.

See Also

• alias: Create an alias for a command
• break: Terminate execution of a block within your processes scope
• exec: Runs an executable
• export: Define an environmental variable and set it's value
• fexec: Execute a command or function, bypassing the usual order of precedence.
• function: Define a function block
• g: Glob pattern matching for file system objects (eg *.txt)
• global: Define a global variable and set it's value
• let: Evaluate a mathematical function and assign to variable (deprecated)
• method: Define a methods supported data-types
• set: Define a local variable and set it's value
• source: Import Murex code from another file of code block