Difference between revisions of "Function"
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<ms>identifier = function(param1, param2, param3) | <ms>identifier = function(param1, param2, param3) | ||
// function body | // function body | ||
− | return 42 | + | return 42 |
end function</ms> | end function</ms> | ||
− | Parameters may have default values. If not otherwise specified, the default value of a parameter is [[null]]. | + | Parameters may have default values. If not otherwise specified, the default value of a parameter is [[null]]. Default values must be literals (not expressions, variables, function calls, etc.). |
<ms>identifier = function(param1=1, param2="foo", param3) | <ms>identifier = function(param1=1, param2="foo", param3) | ||
// function body | // function body | ||
− | return 42 | + | return 42 |
end function</ms> | end function</ms> | ||
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<ms>identifier = function | <ms>identifier = function | ||
// function body | // function body | ||
− | return 42 | + | return 42 |
end function</ms> | end function</ms> | ||
Latest revision as of 15:36, 27 April 2023
function
is a keyword used to define a subprogram in MiniScript. The term "function" can also refer to such a subprogram.
Defining a Function
A typical function definition looks something like this:
identifier = function(param1, param2, param3)
// function body
return 42
end function
Parameters may have default values. If not otherwise specified, the default value of a parameter is null. Default values must be literals (not expressions, variables, function calls, etc.).
identifier = function(param1=1, param2="foo", param3)
// function body
return 42
end function
If the function takes no parameters, then the declaration would look like this:
identifier = function
// function body
return 42
end function
Unlike some other languages, functions in MiniScript do not have names. The function... end function
structure returns a function reference; typically this is assigned to some variable, and then you can call the function via that variable.
Calling a Function
Any time an identifier (with or without dot syntax) that contains a function reference is evaluated, the function is automatically invoked. Parentheses are needed around any arguments to the function if the call is part of a larger expression (rather than a command statement). If no arguments are to be passed to the function, then no parentheses are ever needed.
The following are all valid function calls.
someFunc
someFunc arg1, arg2
x = someFunc
y = someFunc(arg1, arg2)
Function References
Sometimes you want to get a function reference without actually invoking the function. This can be done in two ways:
- Use the
@
operator before the function identifier. This (often read "address of") operator blocks the usual function invocation. Example:f = @someFunc
- Fetch the value out of a map using square-brackets indexing rather than dot syntax. Example:
f = locals["someFunc"]
A function reference has the type funcRef.