CONTRIBUTING.md

CONTRIBUTING

Introduction

This is the contribution guide for Paradise Station. These guidelines apply to both new issues and new pull requests. If you are making a pull request, please refer to the Pull request section, and if you are making an issue report, please refer to the Issue Report section, as well as the Issue Report Template.

Commenting

If you comment on an active pull request or issue report, make sure your comment is concise and to the point. Comments on issue reports or pull requests should be relevant and friendly, not attacks on the author or adages about something minimally relevant. If you believe an issue report is not a "bug", please point out specifically and concisely your reasoning in a comment on the issue itself.

Guidelines:

• Comments on Pull Requests and Issues should remain relevant to the subject in question and not derail discussions.
• Under no circumstances are users to be attacked for their ideas or contributions. All participants on a given PR or issue are expected to be civil. Failure to do so will result in disciplinary action.
  For more details, see the Code of Conduct.

Issues

The Issues section is not a place to request features, or ask for things to be changed because you think they should be that way; The Issues section is specifically for reporting bugs in the code.

Guidelines:

• Issue reports should be as detailed as possible, and if applicable, should include instructions on how to reproduce the bug.

Pull requests

Players are welcome to participate in the development of this fork and submit their own pull requests. If the work you are submitting is a new feature, or affects balance, it is strongly recommended you get approval/traction for it from our forums before starting the actual development.

Guidelines:

• Pull requests should be atomic; Make one commit for each distinct change, so if a part of a pull request needs to be removed/changed, you may simply modify that single commit. Due to limitations of the engine, this may not always be possible; but do try your best.

• Document and explain your pull requests thoroughly. Failure to do so will delay a PR as we question why changes were made. This is especially important if you're porting a PR from another codebase (i.e. TG) and divert from the original. Explaining with single comment on why you've made changes will help us review the PR faster and understand your decision making process.

• Any pull request must have a changelog, this is to allow us to know when a PR is deployed on the live server. Inline changelogs are supported through the format described here and should be used rather than manually edited .yml file changelogs.

• Pull requests should not have any merge commits except in the case of fixing merge conflicts for an existing pull request. New pull requests should not have any merge commits. Use git rebase or git reset to update your branches, not git pull.

• Please explain why you are submitting the pull request, and how you think your change will be beneficial to the game. Failure to do so will be grounds for rejecting the PR.

• If your pull request is not finished make sure it is at least testable in a live environment. Pull requests that do not at least meet this requirement may be closed at maintainer discretion. You may request a maintainer reopen the pull request when you're ready, or make a new one.

• While we have no issue helping contributors (and especially new contributors) bring reasonably sized contributions up to standards via the pull request review process, larger contributions are expected to pass a higher bar of completeness and code quality before you open a pull request. Maintainers may close such pull requests that are deemed to be substantially flawed. You should take some time to discuss with maintainers or other contributors on how to improve the changes.

Using Changelog

• The tags able to be used in the changelog are: add/soundadd/imageadd, del/sounddel/imagedel, tweak, fix, wip, spellcheck, and experiment.

• Without specifying a name it will default to using your GitHub name. Some examples include:

  :cl:
  add: The ability to change the color of wires
  del: Deleted depreciated wire merging now handled in parent
  fix: Moving wires now follows the user input instead of moving the stack
  /:cl:
  

  :cl: UsernameHere
  spellcheck: Fixes some misspelled words under Using Changelog
  /:cl:
  

Specifications

As mentioned before, you are expected to follow these specifications in order to make everyone's lives easier. It'll save both your time and ours, by making sure you don't have to make any changes and we don't have to ask you to. Thank you for reading this section!

Object Oriented Code

As BYOND's Dream Maker (henceforth "DM") is an object-oriented language, code must be object-oriented when possible in order to be more flexible when adding content to it. If you don't know what "object-oriented" means, we highly recommend you do some light research to grasp the basics.

All BYOND paths must contain the full path

(i.e. absolute pathing)

DM will allow you nest almost any type keyword into a block, such as:

datum
  datum1
    var
      varname1 = 1
      varname2
      static
        varname3
        varname4
    proc
      proc1()
        code
      proc2()
        code

    datum2
      varname1 = 0
      proc
        proc3()
          code
      proc2()
        ..()
        code

The use of this format is not allowed in this project, as it makes finding definitions via full text searching next to impossible. The only exception is the variables of an object may be nested to the object, but must not nest further.

The previous code made compliant:

/datum/datum1
  var/varname1 = 1
  var/varname2
  var/static/varname3
  var/static/varname4

/datum/datum1/proc/proc1()
  code
/datum/datum1/proc/proc2()
  code

/datum/datum1/datum2
  varname1 = 0
/datum/datum1/datum2/proc/proc3()
  code
/datum/datum1/datum2/proc2()
  ..()
  code

User Interfaces

All new user interfaces in the game must be created using the TGUI framework. Documentation can be found inside the tgui/docs folder, and the README.md file. This is to ensure all ingame UIs are snappy and respond well. An exception is made for user interfaces which are purely for OOC actions (Such as character creation, or anything admin related)

No overriding type safety checks

The use of the : operator to override type safety checks is not allowed. You must cast the variable to the proper type.

Type paths must begin with a /

eg: /datum/thing, not datum/thing

Datum type paths must began with "datum"

In DM, this is optional, but omitting it makes finding definitions harder. To be specific, you can declare the path /arbitrary, but it will still be, in actuality, /datum/arbitrary. Write your code to reflect this.

Do not use text/string based type paths

It is rarely allowed to put type paths in a text format, as there are no compile errors if the type path no longer exists. Here is an example:

//Bad
var/path_type = "/obj/item/baseball_bat"

//Good
var/path_type = /obj/item/baseball_bat

Do not use \The.

The \The macro doesn't actually do anything when used in the format \The [atom reference]. Directly referencing an atom in an embedded string will automatically prefix The or the to it as appropriate. As an extension, when referencing an atom, don't use [atom.name], use [atom]. The only exception to this rule is when dealing with items "belonging" to a mob, in which case you should use [mob]'s [atom.name] to avoid The ever forming.

//Bad
var/atom/A
"\The [A]"

//Good
var/atom/A
"[A]"

Use the pronoun library instead of \his macros.

We have a system in code/__HELPERS/pronouns.dm for addressing all forms of pronouns. This is useful in a number of ways;

• BYOND's \his macro can be unpredictable on what object it references. Take this example: "[user] waves \his [user.weapon] around, hitting \his opponents!". This will end up referencing the user's gender in the first occurence, but what about the second? It'll actually print the gender set on the weapon he's carrying, which is unintended - and there's no way around this.
• It always prints the real gender variable of the atom it's referencing. This can lead to exposing a mob's gender even when their face is covered, which would normally prevent it's gender from being printed.

The way to avoid these problems is to use the pronoun system. Instead of "[user] waves \his arms.", you can do "[user] waves [user.p_their()] arms."

//Bad
"[H] waves \his hands!"
"[user] waves \his [user.weapon] around, hitting \his opponents!"

//Good
"[H] waves [H.p_their()] hands!"
"[user] waves [H.p_their()] [user.weapon] around, hitting [H.p_their()] opponents!"`

Use [A.UID()] over \ref[A]

BYOND has a system to pass "soft references" to datums, using the format "\ref[datum]" inside a string. This allows you to find the object just based off of a text string, which is especially useful when dealing with the bridge between BYOND code and HTML/JS in UIs. It's resolved back into an object reference by using locate("\ref[datum]") when the code comes back to BYOND. The issue with this is that locate() can return a unexpected datum if the original datum has been deleted - BYOND recycles the references.

UID's are actually unique; they work off of a global counter and are not recycled. Each datum has one assigned to it when it's created, which can be accessed by [datum.UID()]. You can use this as a snap-in replacement for \ref by changing any locate(ref) calls in your code to locateUID(ref). Usage of this system is mandatory for any Topic() calls, and will produce errors in Dream Daemon if it's not used.

//Bad
"<a href='?src=\ref[src];'>Link!</a>"

//Good
"<a href='?src=[UID()];'>Link!</a>"

Use var/name format when declaring variables

While DM allows other ways of declaring variables, this one should be used for consistency.

Tabs, not spaces

You must use tabs to indent your code, NOT SPACES.

(You may use spaces to align something, but you should tab to the block level first, then add the remaining spaces.)

No hacky code

Hacky code, such as adding specific checks (ex: istype(src, /obj/whatever)), is highly discouraged and only allowed when there is no other option. (Protip: 'I couldn't immediately think of a proper way so thus there must be no other option' is not gonna cut it here! If you can't think of anything else, say that outright and admit that you need help with it. Maintainers, PR Reviewers, and other contributors who can help you exist for exactly that reason.)

You can avoid hacky code by using object-oriented methodologies, such as overriding a function (called "procs" in DM) or sectioning code into functions and then overriding them as required.

The same also applies to bugfixes - If an invalid value is being passed into a proc from something that shouldn't have that value, don't fix it on the proc itself, fix it at its origin! (Where feasible)

No duplicated code

Copying code from one place to another may be suitable for small, short-time projects, but Paradise is a long-term project and highly discourages this.

Instead you can use object orientation, or simply placing repeated code in a function, to obey this specification easily.

Startup/Runtime tradeoffs with lists and the "hidden" init proc

First, read the comments in this BYOND thread, starting where the link takes you.

There are two key points here:

1. Defining a list in the variable's definition calls a hidden proc - init. If you have to define a list at startup, do so in New() (or preferably Initialize()) and avoid the overhead of a second call (init() and then New())

2. It also consumes more memory to the point where the list is actually required, even if the object in question may never use it!

Remember: although this tradeoff makes sense in many cases, it doesn't cover them all. Think carefully about your addition before deciding if you need to use it.

Prefer Initialize() over New() for atoms

Our game controller is pretty good at handling long operations and lag, but it can't control what happens when the map is loaded, which calls New() for all atoms on the map. If you're creating a new atom, use the Initialize() proc to do what you would normally do in New(). This cuts down on the number of proc calls needed when the world is loaded.

While we normally encourage (and in some cases, even require) bringing out of date code up to date when you make unrelated changes near the out of date code, that is not the case for New() -> Initialize() conversions. These systems are generally more dependent on parent and children procs, so unrelated random conversions of existing things can cause bugs that take months to figure out.

No implicit var/

When you declare a parameter in a proc, the var/ is implicit. Do not include any implicit var/ when declaring a variable.

//Bad
/obj/item/proc1(var/mob/input1, var/input2)
    code

//Good
/obj/item/proc1(mob/input1, input2)
    code

No magic numbers or strings

This means stuff like having a "mode" variable for an object set to "1" or "2" with no clear indicator of what that means. Make these #defines with a name that more clearly states what it's for. For instance:

//Bad
/datum/proc/do_the_thing(thing_to_do)
    switch(thing_to_do)
        if(1)
            do_stuff()
        if(2)
            do_other_stuff()

There's no indication of what "1" and "2" mean! Instead, you should do something like this:

//Good
#define DO_THE_THING_REALLY_HARD 1
#define DO_THE_THING_EFFICIENTLY 2

/datum/proc/do_the_thing(thing_to_do)
    switch(thing_to_do)
        if(DO_THE_THING_REALLY_HARD)
            do_stuff()
        if(DO_THE_THING_EFFICIENTLY)
            do_other_stuff()

This is clearer and enhances readability of your code! Get used to doing it!

Control statements

(if, while, for, etc)

• All control statements comparing a variable to a number should use the formula of thing operator number, not the reverse (eg: if(count <= 10) not if(10 >= count))

• All control statements must be spaced as if(), with the brackets touching the keyword.

• All control statements must not contain code on the same line as the statement.

  //Bad
  if(x) return
  
  //Good
  if(x)
      return

Player Output

Due to the use of "Goonchat", Paradise requires a special syntax for outputting text messages to players. Instead of mob << "message", you must use to_chat(mob, "message"). Failure to do so will lead to your code not working.

Use early returns

Do not enclose a proc in an if-block when returning on a condition is more feasible.

This is bad:

/datum/datum1/proc/proc1()
    if(thing1)
        if(!thing2)
            if(thing3 == 30)
                do stuff

This is good:

/datum/datum1/proc/proc1()
    if(!thing1)
        return
    if(thing2)
        return
    if(thing3 != 30)
        return
    do stuff

This prevents nesting levels from getting deeper then they need to be.

Use addtimer() instead of sleep() or spawn()

If you need to call a proc after a set amount of time, use addtimer() instead of spawn() / sleep() where feasible. Though more complex, this method has greater performance. Additionally, unlike spawn() or sleep(), it can be cancelled. For more details, see tgstation/tgstation#22933.

Look for code examples on how to properly use it.

//Bad
/datum/datum1/proc/proc1(target)
    spawn(5 SECONDS)
    target.dothing(arg1, arg2, arg3)

//Good
/datum/datum1/proc/proc1(target)
    addtimer(CALLBACK(target, .proc/dothing, arg1, arg2, arg3), 5 SECONDS)

This prevents nesting levels from getting deeper then they need to be.

Operators

Spacing

• Operators that should be separated by spaces:
  • Boolean and logic operators like &&, || <, >, ==, etc. (But not !)
  • Bitwise AND & and OR |.
  • Argument separator operators like ,. (and ; when used in a forloop)
  • Assignment operators like = or += or the like.
  • Math operators like +, -, /, or *.
• Operators that should NOT be separated by spaces:
  • Access operators like . and :.
  • Parentheses ().
  • Logical not !.

Use

• Bitwise AND &

  • Should be written as bitfield & bitflag NEVER bitflag & bitfield, both are valid, but the latter is confusing and nonstandard.

• Associated lists declarations must have their key value quoted if it's a string

  //Bad
  list(a = "b")
  
  //Good
  list("a" = "b")

Bitflags

• We prefer using bitshift operators instead of directly typing out the value. I.E:

  #define MACRO_ONE (1<<0)
  #define MACRO_TWO (1<<1)
  #define MACRO_THREE (1<<2)
  

  Is preferable to:

  #define MACRO_ONE 1
  #define MACRO_TWO 2
  #define MACRO_THREE 4
  

  While it may initially look intimidating, (1<<x) is actually very simple and, as the name implies, shifts the bits of a given binary number over by one digit.

  000100 (4, or (1<<2))
  <<
  001000 (8, or (1<<3))
  

  Using this system makes the code more readable and less prone to error.

Legacy Code

SS13 has a lot of legacy code that's never been updated. Here are some examples of common legacy trends which are no longer acceptable:

• To display messages to all mobs that can view user, you should use visible_message().

  //Bad
  for(var/mob/M in viewers(user))
      M.show_message("<span class='warning'>Arbitrary text</span>")
  
  //Good
  user.visible_message("<span class='warning'>Arbitrary text</span>")

• You should not use color macros (\red, \blue, \green, \black) to color text, instead, you should use span classes. <span class='warning'>Red text</span>, <span class='notice'>Blue text</span>.

  //Bad
  to_chat(user, "\red Red text \black Black text")
  
  //Good
  to_chat(user, "<span class='warning'>Red text</span>Black text")
  

• To use variables in strings, you should never use the text() operator, use embedded expressions directly in the string.

  //Bad
  to_chat(user, text("[] is leaking []!", name, liquid_type))
  
  //Good
  to_chat(user, "[name] is leaking [liquid_type]!")

• To reference a variable/proc on the src object, you should not use src.var/src.proc(). The src. in these cases is implied, so you should just use var/proc().

  //Bad
  var/user = src.interactor
  src.fill_reserves(user)
  
  //Good
  var/user = interactor
  fill_reserves(user)

Develop Secure Code

• Player input must always be escaped safely, we recommend you use stripped_input() in all cases where you would use input. Essentially, just always treat input from players as inherently malicious and design with that use case in mind.

• Calls to the database must be escaped properly - use proper parameters (values starting with a :). You can then replace these with a list of parameters, and these will be properly escaped during the query, and prevent any SQL injection.

  //Bad
  var/datum/db_query/query_watch = SSdbcore.NewQuery("SELECT reason FROM [format_table_name("watch")] WHERE ckey='[target_ckey]'")
  
  //Good
  var/datum/db_query/query_watch = SSdbcore.NewQuery("SELECT reason FROM [format_table_name("watch")] WHERE ckey=:target_ckey", list(
    "target_ckey" = target_ckey
  )) // Note the use of parameters on the above line and :target_ckey in the query.

• All calls to topics must be checked for correctness. Topic href calls can be easily faked by clients, so you should ensure that the call is valid for the state the item is in. Do not rely on the UI code to provide only valid topic calls, because it won't.

• Information that players could use to metagame (that is, to identify round information and/or antagonist type via information that would not be available to them in character) should be kept as administrator only.

• Where you have code that can cause large-scale modification and FUN, make sure you start it out locked behind one of the default admin roles - use common sense to determine which role fits the level of damage a function could do.

Files

• Because runtime errors do not give the full path, try to avoid having files with the same name across folders.

• File names should not be mixed case, or contain spaces or any character that would require escaping in a uri.

• Files and path accessed and referenced by code above simply being #included should be strictly lowercase to avoid issues on filesystems where case matters.

SQL

• Do not use the shorthand sql insert format (where no column names are specified) because it unnecessarily breaks all queries on minor column changes and prevents using these tables for tracking outside related info such as in a connected site/forum.

• Use parameters for queries, as mentioned above in Develop Secure Code.

• Always check your queries for success with if(!query.warn_execute()). By using this standard format, you can ensure the correct log messages are used.

• Always qdel() your queries after you are done with them, this cleans up the results and helps things run smoother.

• All changes to the database's layout (schema) must be specified in the database changelog in SQL, as well as reflected in the schema file.

• Any time the schema is changed the SQL_VERSION defines must be incremented, as well as the example config, with an appropriate conversion kit placed in the SQL/updates folder.

• Queries must never specify the database, be it in code, or in text files in the repo.

Mapping Standards

• Map Merge

  • The following guideline for map merging applies to people who are NOT using StrongDMM, please see the StrongDMM section if you are.
    • You MUST run Map Merge prior to opening your PR when updating existing maps to minimize the change differences (even when using third party mapping programs such as FastDMM.)
    • Failure to run Map Merge on a map after using third party mapping programs (such as FastDMM) greatly increases the risk of the map's key dictionary becoming corrupted by future edits after running map merge. Resolving the corruption issue involves rebuilding the map's key dictionary;

• StrongDMM

  • When using StrongDMM, the following options MUST be enabled to avoid file bloat. They can be found under File > Preferences > Save Options in SDMM.
    • Map save format: This MUST be set to TGM if you do not want to run Map Merge. Enabling this setting means SDMM will automatically map merge, letting you skip manual merging.
    • Sanitize Variables - Removes variables that are declared on the map, but are the same as default. (For example: A standard floor turf that has dir = 2 declared on the map will have that variable deleted as it is redundant.)
    • Clean Unused Keys - Removes content tile keys that are no longer used on the map, usually leftover keys from deletions or edits.

• Variable Editing (Var-edits)

  • While var-editing an item within the editor is perfectly fine, it is preferred that when you are changing the base behavior of an item (how it functions) that you make a new subtype of that item within the code, especially if you plan to use the item in multiple locations on the same map, or across multiple maps. This makes it easier to make corrections as needed to all instances of the item at one time as opposed to having to find each instance of it and change them all individually.
    • Subtypes only intended to be used on away mission or ruin maps should be contained within an .dm file with a name corresponding to that map within code\modules\awaymissions or code\modules\ruins respectively. This is so in the event that the map is removed, that subtype will be removed at the same time as well to minimize leftover/unused data within the repo.
  • Please attempt to clean out any dirty variables that may be contained within items you alter through var-editing. For example, due to how DM functions, changing the pixel_x variable from 23 to 0 will leave a dirty record in the map's code of pixel_x = 0. Likewise this can happen when changing an item's icon to something else and then back. This can lead to some issues where an item's icon has changed within the code, but becomes broken on the map due to it still attempting to use the old entry.
  • Areas should not be var-edited on a map to change it's name or attributes. All areas of a single type and it's altered instances are considered the same area within the code, and editing their variables on a map can lead to issues with powernets and event subsystems which are difficult to debug.

• If you are making non-minor edits to an area or room, (non-minor being anything more than moving a few objects or fixing small bugs) then you should ensure the entire area/room meets these standards.

• When making a change to an area or room, follow these guidelines:

  • Unless absolutely necessary, do not run pipes (including disposals) under wall turfs.

  • NEVER run cables under wall turfs.

  • Keep floor turf variations to a minimum. Generally, more than 3 floor turf types in one room is bad design.

  • Run air pipes together where possible. The first example below is to be avoided, the second is optimal:

    

  • Pipe layouts should be logical and predictable, easy to understand at a glance. Always avoid complex layouts like in this example:

    

  • Decals are to be used sparingly. Good map design does not require warning tape around everything. Decal overuse contributes to maptick slowdown.

  • Every area should contain only one APC and air alarm.

    • Critical infrastructure rooms (such as the engine, arrivals, and medbay areas) should be given an APC with a larger power cell.

  • Every room should contain at least one fire alarm, air vent and scrubber, light switch, station intercom, and security camera.

    • Intercoms should be set to frequency 145.9, and be speaker ON Microphone OFF. This is so radio signals can reach people even without headsets on. Larger room will require more than one at a time.
    • Exceptions can be made to security camera placement for certain rooms, such as the execution room. Larger rooms may require more than one security camera. All security cameras should have a descriptive name that makes it easy to find on a camera console.
      • A good example would be the template [Department name] - [Area], so Brig - Cell 1, or Medbay - Treatment Center. Consistency is key to good camera naming.
    • Fire alarms should not be placed next to expected heat sources.
    • Use the following "on" subtype of vents and scrubbers as opposed to var-editing: /obj/machinery/atmospherics/unary/vent_scrubber/on and /obj/machinery/atmospherics/unary/vent_pump/on

  • Head of staff officers should contain a requests console.

  • Firelocks should be used at area boundaries over doors and windows. Firelocks can also be used to break up hallways at reasonable intervals.

    • Double firelocks are to be avoided unless absolutely necessary.
    • Maintenance access doors should not have firelocks placed over them.

  • Windows to secure areas or external areas should be reinforced. Windows in engine areas should be reinforced plasma glass.

    • Windows in high security areas, such as the brig, bridge, and head of staff offices, should be electrified by placing a wire node under the window.

  • Lights are to be used sparingly, they draw a significant amount of power.

  • Ensure door and windoor access is correctly set, these are handled by the variables req_access_txt and req_one_access_txt. Public doors should have both of these values as "0". For a list of access values, see code\__DEFINES\access.dm.

    • Always use numerical values encased in quotes for these variables. Multiple access values can be defined by separating them with a ;, for example: "28;31" for kitchen AND cargo access.
    • req_access_txt requires ALL LISTED ACCESSES to open the door, while req_one_access_txt lets anyone with ONE OF THE LISTED ACCESSES open the door.

  • Departments should be connected to maintenance through a back or side door. This lets players escape and allows antags to break in.

    • If this is not possible, departments should have extra entry and exit points.

  • Engine areas, or areas with a high probability of receiving explosions, should use reinforced flooring if appropriate.

  • External areas, or areas where depressurisation is expected and normal, should use airless turf variants to prevent additional atmospherics load.

  • Edits in mapping tools should generally be possible to replicate in-game. For this reason, avoid stacking multiple structures on the same tile (i.e. placing a light and an APC on the same wall.)

Other Notes

• Code should be modular where possible; if you are working on a new addition, then strongly consider putting it in its own file unless it makes sense to put it with similar ones (i.e. a new tool would go in the tools.dm file)

• Bloated code may be necessary to add a certain feature, which means there has to be a judgement over whether the feature is worth having or not. You can help make this decision easier by making sure your code is modular.

• You are expected to help maintain the code that you add, meaning that if there is a problem then you are likely to be approached in order to fix any issues, runtimes, or bugs.

• If you used regex to replace code during development of your code, post the regex in your PR for the benefit of future developers and downstream users.

• All new var/proc names should use the American English spelling of words. This is for consistency with BYOND.

Dream Maker Quirks/Tricks

Like all languages, Dream Maker has its quirks, some of them are beneficial to us, like these:

In-To for-loops

for(var/i = 1, i <= some_value, i++) is a fairly standard way to write an incremental for loop in most languages (especially those in the C family), but DM's for(var/i in 1 to some_value) syntax is oddly faster than its implementation of the former syntax; where possible, it's advised to use DM's syntax. ( Note, the to keyword is inclusive, so it automatically defaults to replacing <=; if you want < then you should write it as 1 to some_value-1).

HOWEVER, if either some_value or i changes within the body of the for (underneath the for(...) header) or if you are looping over a list AND changing the length of the list then you can NOT use this type of for-loop!

for(var/A in list) VS for(var/i in 1 to list.len)

The former is faster than the latter, as shown by the following profile results: https://file.house/zy7H.png
Code used for the test in a readable format: https://pastebin.com/w50uERkG

Istypeless for loops

A name for a differing syntax for writing for-each style loops in DM. It's NOT DM's standard syntax, hence why this is considered a quirk. Take a look at this:

var/list/bag_of_items = list(sword1, apple, coinpouch, sword2, sword3)
var/obj/item/sword/best_sword
for(var/obj/item/sword/S in bag_of_items)
  if(!best_sword || S.damage > best_sword.damage)
    best_sword = S

The above is a simple proc for checking all swords in a container and returning the one with the highest damage, and it uses DM's standard syntax for a for-loop by specifying a type in the variable of the for's header that DM interprets as a type to filter by. It performs this filter using istype() (or some internal-magic similar to istype() - this is BYOND, after all). This is fine in its current state for bag_of_items, but if bag_of_items contained ONLY swords, or only SUBTYPES of swords, then the above is inefficient. For example:

var/list/bag_of_swords = list(sword1, sword2, sword3, sword4)
var/obj/item/sword/best_sword
for(var/obj/item/sword/S in bag_of_swords)
  if(!best_sword || S.damage > best_sword.damage)
    best_sword = S

specifies a type for DM to filter by.

With the previous example that's perfectly fine, we only want swords, but if the bag only contains swords? Is DM still going to try to filter because we gave it a type to filter by? YES, and here comes the inefficiency. Wherever a list (or other container, such as an atom (in which case you're technically accessing their special contents list, but that's irrelevant)) contains datums of the same datatype or subtypes of the datatype you require for your loop's body, you can circumvent DM's filtering and automatic istype() checks by writing the loop as such:

var/list/bag_of_swords = list(sword, sword, sword, sword)
var/obj/item/sword/best_sword
for(var/s in bag_of_swords)
  var/obj/item/sword/S = s
  if(!best_sword || S.damage > best_sword.damage)
    best_sword = S

Of course, if the list contains data of a mixed type then the above optimisation is DANGEROUS, as it will blindly typecast all data in the list as the specified type, even if it isn't really that type, causing runtime errors (AKA your shit won't work if this happens).

Dot variable

Like other languages in the C family, DM has a . or "Dot" operator, used for accessing variables/members/functions of an object instance. eg:

var/mob/living/carbon/human/H = YOU_THE_READER
H.gib()

However, DM also has a dot variable, accessed just as . on its own, defaulting to a value of null. Now, what's special about the dot operator is that it is automatically returned (as in the return statement) at the end of a proc, provided the proc does not already manually return (return count for example.) Why is this special?

With . being everpresent in every proc, can we use it as a temporary variable? Of course we can! However, the . operator cannot replace a typecasted variable - it can hold data any other var in DM can, it just can't be accessed as one, although the . operator is compatible with a few operators that look weird but work perfectly fine, such as: .++ for incrementing .'s value, or .[1] for accessing the first element of ., provided that it's a list.

Globals versus static

DM has a var keyword, called global. This var keyword is for vars inside of types. For instance:

/mob
  var/global/thing = TRUE

This does NOT mean that you can access it everywhere like a global var. Instead, it means that that var will only exist once for all instances of its type, in this case that var will only exist once for all mobs - it's shared across everything in its type. (Much more like the keyword static in other languages like PHP/C++/C#/Java)

Isn't that confusing?

There is also an undocumented keyword called static that has the same behaviour as global but more correctly describes BYOND's behaviour. Therefore, we always use static instead of global where we need it, as it reduces suprise when reading BYOND code.

Global Vars

All new global vars must use the defines in code/__DEFINES/_globals.dm. Basic usage is as follows:

To declare a global var:

GLOBAL_VAR(my_global_here)

To access it:

GLOB.my_global_here = X

There are a few other defines that do other things. GLOBAL_REAL shouldn't be used unless you know exactly what you're doing. GLOBAL_VAR_INIT allows you to set an initial value on the var, like GLOBAL_VAR_INIT(number_one, 1). GLOBAL_LIST_INIT allows you to define a list global var with an initial value. Etc.

Maintainers

The only current official role for GitHub staff are the Maintainers. They share equal power. The Maintainers are responsible for properly tagging new pull requests and issues, moderating comments in pull requests/issues, and merging/closing pull requests.

Maintainer List

• AffectedArc07
• Ansari
• Crazy Lemon
• Fox P McCloud

Maintainer instructions

• Do not "self-merge"; this refers to the practice of opening a pull request, then merging it yourself. A different maintainer must review and merge your pull request, no matter how trivial. This is to ensure quality.
  • A subset of this instruction: Do not push directly to the repository, always make a pull request.
• Wait for the CI build to complete. If it fails, the pull request may only be merged if there is a very good reason (example: fixing the CI configuration).
• Pull requests labeled as bugfixes and refactors may be merged as soon as they are reviewed.
• The shortest waiting period for -any- feature or balancing altering pull request is 24 hours, to allow other coders and the community time to discuss the proposed changes.
• If the discussion is active, or the change is controversial, the pull request is to be put on hold until a consensus is reached.
• To keep commit history easy to navigate for future contributors (e.g. Git Blame), squash merge is to be preferred to normal merge where suitable. Ensure that the squashed commit name is easy to understand and read. Modify it if needed.