Difference between revisions of "Macro Functions"
From GiderosMobile
(formatting + added another example from @perrochon) |
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'''<translate>Supported platforms</translate>:''' [[File:Platform android.png]][[File:Platform ios.png]][[File:Platform mac.png]][[File:Platform pc.png]]<br/> | '''<translate>Supported platforms</translate>:''' [[File:Platform android.png]][[File:Platform ios.png]][[File:Platform mac.png]][[File:Platform pc.png]]<br/> | ||
'''<translate>Available since</translate>:''' Gideros 2017.10<br/> | '''<translate>Available since</translate>:''' Gideros 2017.10<br/> | ||
+ | |||
=== <translate>Description</translate> === | === <translate>Description</translate> === | ||
− | + | Macro Functions receive a list of tokens and output a string which will be pasted into code at compile time. | |
− | Macro Functions receive a list of tokens and output a string which will be pasted into code at compile time.< | + | <source lang="lua"> |
+ | name @ (| ...body... |) | ||
+ | </source> | ||
+ | |||
+ | You should use parenthesis around markers - '|' is the preferred marker. | ||
+ | |||
+ | The same marker should be used to close macro body with closing parenthesis right after it. | ||
+ | |||
+ | You can use any of these markers: | ||
− | + | '''\`~ ! # $ % ^ & * / + = |''' | |
− | You | + | You can redefine a macro with @@: |
− | + | <source lang="lua"> | |
− | + | name @@ (| ...another_body... |) | |
+ | </source> | ||
− | + | To call macro function use its name with parenthesis as with usual functions: | |
− | name | + | <source lang="lua"> |
+ | name(...arguments...) | ||
+ | </source> | ||
− | |||
− | |||
=== <translate>Examples</translate> === | === <translate>Examples</translate> === | ||
− | '''Enumeration''' | + | '''Enumeration''' |
− | <source lang="lua"> | + | <source lang="lua"> |
enum @ (| | enum @ (| | ||
local t = ... | local t = ... | ||
Line 31: | Line 41: | ||
return table.concat(r, " ") | return table.concat(r, " ") | ||
|) | |) | ||
− | + | ||
enum(apple, orange, melon) | enum(apple, orange, melon) | ||
print(apple, orange, melon) --> 1 2 3</source> | print(apple, orange, melon) --> 1 2 3</source> | ||
− | '''Turning off the print command''' | + | |
− | <source lang="lua"> | + | '''Turning off the print command''' |
− | print @ (| return "" |)</source> | + | <source lang="lua"> |
− | '''Unroll loops''' | + | print @ (| return "" |) |
− | <source lang="lua"> | + | </source> |
+ | |||
+ | '''Unroll loops''' | ||
+ | <source lang="lua"> | ||
dotimes @ (| | dotimes @ (| | ||
local times = table.remove(..., 1) | local times = table.remove(..., 1) | ||
return (table.concat(..., " ").." "):rep(times) | return (table.concat(..., " ").." "):rep(times) | ||
|) | |) | ||
− | + | ||
local t = {} | local t = {} | ||
− | + | ||
− | dotimes(10 print "Boom!")</source> | + | dotimes(10 print "Boom!") |
+ | </source> | ||
+ | |||
+ | '''A Sum macro example''' | ||
+ | <source lang="lua"> | ||
+ | -- comma counts as an argument meaning SUM(o1, o2) has three parameters | ||
+ | SUM @ (| return "("..(...)[1] + (...)[3] ..")" |) | ||
+ | print (SUM(1,2) * SUM(3,1)) | ||
+ | </source> | ||
+ | |||
{|- | {|- | ||
| style="width: 50%; vertical-align:top;"| | | style="width: 50%; vertical-align:top;"| |
Revision as of 22:05, 20 June 2020
Supported platforms:
Available since: Gideros 2017.10
Description
Macro Functions receive a list of tokens and output a string which will be pasted into code at compile time.
name @ (| ...body... |)
You should use parenthesis around markers - '|' is the preferred marker.
The same marker should be used to close macro body with closing parenthesis right after it.
You can use any of these markers:
\`~ ! # $ % ^ & * / + = |
You can redefine a macro with @@:
name @@ (| ...another_body... |)
To call macro function use its name with parenthesis as with usual functions:
name(...arguments...)
Examples
Enumeration
enum @ (|
local t = ...
local r = {}
for i = 1, #t, 2 do
table.insert(r, t[i] .. " @ " .. i // 2 + 1)
end
print(table.concat(r, " "))
return table.concat(r, " ")
|)
enum(apple, orange, melon)
print(apple, orange, melon) --> 1 2 3
Turning off the print command
print @ (| return "" |)
Unroll loops
dotimes @ (|
local times = table.remove(..., 1)
return (table.concat(..., " ").." "):rep(times)
|)
local t = {}
dotimes(10 print "Boom!")
A Sum macro example
-- comma counts as an argument meaning SUM(o1, o2) has three parameters
SUM @ (| return "("..(...)[1] + (...)[3] ..")" |)
print (SUM(1,2) * SUM(3,1))
Methods |
EventsConstants |