Difference between revisions of "Case"
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== Description == | == Description == | ||
| − | Calling case returns a case closure with one defined method, [[case.on|on]]. This closure can stand in place of complicated if-elseif code and functions analogously to the C language switch case construct except that it can be called anywhere once defined. The first parameter passed to the [[case.on|on]] method selects a function from the initial case table and calls it with the remaining parameters passed through. | + | Calling case returns a case closure with one defined method, [[case.on|on]]. This closure can stand in place of complicated if-elseif code and functions analogously to the C language switch case construct except that it can be called anywhere once defined. The first parameter passed to the [[case.on|on]] method selects a function from the initial case table and calls it with the remaining parameters passed through. If the selector isn't found among the case table keys, then the default key 'default' is searched for and if found, the associated function is called. If neither the selector value or 'default' is found in the case table, then an error is raised. |
== Alternative Calling Patterns == | == Alternative Calling Patterns == | ||
Revision as of 12:15, 2 November 2010
Contents
Calling Pattern
Call
local c = sl.case(casetable)
Args
casetable is a table, where keys are any type and values are functions
Results
c is a case closure
Closure Methods
Example Usage
local t =
{
[1] = function(...) local a={...} print('a') print(a[a[5] ]) end,
['1'] = function(...) local a={...} print('b') print(a[a[4] ]) end,
bye = function(...) local a={...} print('c') print(a[a[3] ]) end,
default = function(...) local a={...} print('d') print(a[a[2] ]) end,
}
local c = sl.case(t)
local z = 'bye'
c.on(z,2,3,4,5,6)
--> 'c' --> 5
Description
Calling case returns a case closure with one defined method, on. This closure can stand in place of complicated if-elseif code and functions analogously to the C language switch case construct except that it can be called anywhere once defined. The first parameter passed to the on method selects a function from the initial case table and calls it with the remaining parameters passed through. If the selector isn't found among the case table keys, then the default key 'default' is searched for and if found, the associated function is called. If neither the selector value or 'default' is found in the case table, then an error is raised.
