lua switch works similarly to the javascript version of the switch statement.
its syntax is similar to the lua implementation of promises
local switch = require(somewhere.switch)
local randomValue = 45
switch(randomValue)
:case(45, function()
print("this prints")
end)
:case(12, function()
print("this will never print")
end)
:default(function()
print("this will always print")
end)As it's shown, switch statements are very similar to if statements. case uses the == operator to compare values. If a match is made the callback function runs. default runs no matter what, as long as the switch execution isnt haulted before it's chained, which we will cover next.
switch(1)
:case(1, function()
return true
end)
:case(1, function()
error("we never reach this point")
end)
:default(function()
error("we never reach this point either")
end)
switch(1)
:default(function()
print("position in the chain matters")
return true
end)
:case(1, function()
error("we never reach this point")
end)by returning true within a case callback, the switch execution will then be haulted. default blocks work identically to cases in the sense that returning true will hault the execution
unlike javascript, omitting the return statement does not execute the next case regardless of evaluation
Something different than javascript is switched values can be transformed. Lets revisit the first example and this time use our transformer function to see if we can get a different result.
local randomValue = 45
switch(randomValue)
:case(45, function(transform)
print("this prints")
local newValue = transform(12)
-- the transformer function also returns the new transformed value
end)
:case(12, function()
print("this will print now")
end)
:default(function()
print("this will always print")
end)By chaining our cases, we will vist each case in order testing our value, making the transformer function valuable for downstream cases.
the transformer function is not present for use within a default block