LUA_API.rst

DFHack Lua API

Contents

• DF data structure wrapper
  • Typed object references
    • Primitive references
    • Struct references
    • Container references
    • Bitfield references
  • Named types
  • Global functions
  • Recursive table assignment
• DFHack API
  • Native utilities
    • Input & Output
    • Exception handling
    • Miscellaneous
    • Locking and finalization
    • Persistent configuration storage
    • Material info lookup
  • C++ function wrappers
    • Gui module
    • Job module
    • Units module
    • Items module
    • Maps module
    • Burrows module
    • Buildings module
    • Constructions module
    • Screen API
    • Internal API
  • Core interpreter context
    • Event type
• Lua Modules
  • Global environment
  • utils
  • dumper
  • class
• Plugins
  • burrows
  • sort
• Scripts

The current version of DFHack has extensive support for the Lua scripting language, providing access to:

1. Raw data structures used by the game.
2. Many C++ functions for high-level access to these structures, and interaction with dfhack itself.
3. Some functions exported by C++ plugins.

Lua code can be used both for writing scripts, which are treated by DFHack command line prompt almost as native C++ commands, and invoked by plugins written in c++.

This document describes native API available to Lua in detail. It does not describe all of the utility functions implemented by Lua files located in hack/lua/...

DF data structure wrapper

DF structures described by the xml files in library/xml are exported to lua code as a tree of objects and functions under the df global, which broadly maps to the df namespace in C++.

WARNING: The wrapper provides almost raw access to the memory of the game, so mistakes in manipulating objects are as likely to crash the game as equivalent plain C++ code would be. E.g. NULL pointer access is safely detected, but dangling pointers aren't.

Objects managed by the wrapper can be broadly classified into the following groups:

1. Typed object pointers (references).

   References represent objects in DF memory with a known type.

   In addition to fields and methods defined by the wrapped type, every reference has some built-in properties and methods.

2. Untyped pointers

   Represented as lightuserdata.

   In assignment to a pointer NULL can be represented either as nil, or a NULL lightuserdata; reading a NULL pointer field returns nil.

3. Named types

   Objects in the df tree that represent identity of struct, class, enum and bitfield types. They host nested named types, static methods, builtin properties & methods, and, for enums and bitfields, the bi-directional mapping between key names and values.

4. The global object

   df.global corresponds to the df::global namespace, and behaves as a mix between a named type and a reference, containing both nested types and fields corresponding to global symbols.

In addition to the global object and top-level types the df global also contains a few global builtin utility functions.

Typed object references

The underlying primitive lua object is userdata with a metatable. Every structured field access produces a new userdata instance.

All typed objects have the following built-in features:

• ref1 == ref2, tostring(ref)

  References implement equality by type & pointer value, and string conversion.

• pairs(ref)

  Returns an iterator for the sequence of actual C++ field names and values. Fields are enumerated in memory order. Methods and lua wrapper properties are not included in the iteration.

  WARNING: a few of the data structures (like ui_look_list) contain unions with pointers to different types with vtables. Using pairs on such structs is an almost sure way to crash with an access violation.

• ref._kind

  Returns one of: primitive, struct, container, or bitfield, as appropriate for the referenced object.

• ref._type

  Returns the named type object or a string that represents the referenced object type.

• ref:sizeof()

  Returns size, address

• ref:new()

  Allocates a new instance of the same type, and copies data from the current object.

• ref:delete()

  Destroys the object with the C++ delete operator. If destructor is not available, returns false.

  WARNING: the lua reference object remains as a dangling pointer, like a raw C++ pointer would.

• ref:assign(object)

  Assigns data from object to ref. Object must either be another ref of a compatible type, or a lua table; in the latter case special recursive assignment rules are applied.

• ref:_displace(index[,step])

  Returns a new reference with the pointer adjusted by index*step. Step defaults to the natural object size.

Primitive references

References of the _kind 'primitive' are used for objects that don't fit any of the other reference types. Such references can only appear as a value of a pointer field, or as a result of calling the _field() method.

They behave as structs with one field value of the right type.

To make working with numeric buffers easier, they also allow numeric indices. Note that other than excluding negative values no bound checking is performed, since buffer length is not available. Index 0 is equivalent to the value field.

Struct references

Struct references are used for class and struct objects.

They implement the following features:

• ref.field, ref.field = value

  Valid fields of the structure may be accessed by subscript.

  Primitive typed fields, i.e. numbers & strings, are converted to/from matching lua values. The value of a pointer is a reference to the target, or nil/NULL. Complex types are represented by a reference to the field within the structure; unless recursive lua table assignment is used, such fields can only be read.

  NOTE: In case of inheritance, superclass fields have precedence over the subclass, but fields shadowed in this way can still be accessed as ref['subclasstype.field']. This shadowing order is necessary because vtable-based classes are automatically exposed in their exact type, and the reverse rule would make access to superclass fields unreliable.

• ref._field(field)

  Returns a reference to a valid field. That is, unlike regular subscript, it returns a reference to the field within the structure even for primitive typed fields and pointers.

• ref:vmethod(args...)

  Named virtual methods are also exposed, subject to the same shadowing rules.

• pairs(ref)

  Enumerates all real fields (but not methods) in memory (= declaration) order.

Container references

Containers represent vectors and arrays, possibly resizable.

A container field can associate an enum to the container reference, which allows accessing elements using string keys instead of numerical indices.

Implemented features:

• ref._enum

  If the container has an associated enum, returns the matching named type object.

• #ref

  Returns the length of the container.

• ref[index]

  Accesses the container element, using either a 0-based numerical index, or, if an enum is associated, a valid enum key string.

  Accessing an invalid index is an error, but some container types may return a default value, or auto-resize instead for convenience. Currently this relaxed mode is implemented by df-flagarray aka BitArray.

• ref._field(index)

  Like with structs, returns a pointer to the array element, if possible. Flag and bit arrays cannot return such pointer, so it fails with an error.

• pairs(ref), ipairs(ref)

  If the container has no associated enum, both behave identically, iterating over numerical indices in order. Otherwise, ipairs still uses numbers, while pairs tries to substitute enum keys whenever possible.

• ref:resize(new_size)

  Resizes the container if supported, or fails with an error.

• ref:insert(index,item)

  Inserts a new item at the specified index. To add at the end, use #ref, or just '#' as index.

• ref:erase(index)

  Removes the element at the given valid index.

Bitfield references

Bitfields behave like special fixed-size containers. Consider them to be something in between structs and fixed-size vectors.

The _enum property points to the bitfield type. Numerical indices correspond to the shift value, and if a subfield occupies multiple bits, the ipairs order would have a gap.

Since currently there is no API to allocate a bitfield object fully in GC-managed lua heap, consider using the lua table assignment feature outlined below in order to pass bitfield values to dfhack API functions that need them, e.g. matinfo:matches{metal=true}.

Named types

Named types are exposed in the df tree with names identical to the C++ version, except for the :: vs . difference.

All types and the global object have the following features:

• type._kind

  Evaluates to one of struct-type, class-type, enum-type, bitfield-type or global.

• type._identity

  Contains a lightuserdata pointing to the underlying DFHack::type_instance object.

Types excluding the global object also support:

• type:sizeof()

  Returns the size of an object of the type.

• type:new()

  Creates a new instance of an object of the type.

• type:is_instance(object)

  Returns true if object is same or subclass type, or a reference to an object of same or subclass type. It is permissible to pass nil, NULL or non-wrapper value as object; in this case the method returns nil.

In addition to this, enum and bitfield types contain a bi-directional mapping between key strings and values, and also map _first_item and _last_item to the min and max values.

Struct and class types with instance-vector attribute in the xml have a type.find(key) function that wraps the find method provided in C++.

Global functions

The df table itself contains the following functions and values:

• NULL, df.NULL

  Contains the NULL lightuserdata.

• df.isnull(obj)

  Evaluates to true if obj is nil or NULL; false otherwise.

• df.isvalid(obj[,allow_null])

  For supported objects returns one of type, voidptr, ref.

  If allow_null is true, and obj is nil or NULL, returns null.

  Otherwise returns nil.

• df.sizeof(obj)

  For types and refs identical to obj:sizeof(). For lightuserdata returns nil, address

• df.new(obj), df.delete(obj), df.assign(obj, obj2)

  Equivalent to using the matching methods of obj.

• df._displace(obj,index[,step])

  For refs equivalent to the method, but also works with lightuserdata (step is mandatory then).

• df.is_instance(type,obj)

  Equivalent to the method, but also allows a reference as proxy for its type.

• df.new(ptype[,count])

  Allocate a new instance, or an array of built-in types. The ptype argument is a string from the following list: string, int8_t, uint8_t, int16_t, uint16_t, int32_t, uint32_t, int64_t, uint64_t, bool, float, double. All of these except string can be used with the count argument to allocate an array.

• df.reinterpret_cast(type,ptr)

  Converts ptr to a ref of specified type. The type may be anything acceptable to df.is_instance. Ptr may be nil, a ref, a lightuserdata, or a number.

  Returns nil if NULL, or a ref.

Recursive table assignment

Recursive assignment is invoked when a lua table is assigned to a C++ object or field, i.e. one of:

• ref:assign{...}
• ref.field = {...}

The general mode of operation is that all fields of the table are assigned to the fields of the target structure, roughly emulating the following code:

function rec_assign(ref,table)
    for key,value in pairs(table) do
        ref[key] = value
    end
end

Since assigning a table to a field using = invokes the same process, it is recursive.

There are however some variations to this process depending on the type of the field being assigned to:

1. If the table contains an assign field, it is applied first, using the ref:assign(value) method. It is never assigned as a usual field.

2. When a table is assigned to a non-NULL pointer field using the ref.field = {...} syntax, it is applied to the target of the pointer instead.

   If the pointer is NULL, the table is checked for a new field:

   1. If it is nil or false, assignment fails with an error.
   2. If it is true, the pointer is initialized with a newly allocated object of the declared target type of the pointer.
   3. Otherwise, table.new must be a named type, or an object of a type compatible with the pointer. The pointer is initialized with the result of calling table.new:new().

   After this auto-vivification process, assignment proceeds as if the pointer wasn't NULL.

   Obviously, the new field inside the table is always skipped during the actual per-field assignment processing.

3. If the target of the assignment is a container, a separate rule set is used:

   1. If the table contains neither assign nor resize fields, it is interpreted as an ordinary 1-based lua array. The container is resized to the #-size of the table, and elements are assigned in numeric order:

      ref:resize(#table);
      for i=1,#table do ref[i-1] = table[i] end
      

   2. Otherwise, resize must be true, false, or an explicit number. If it is not false, the container is resized. After that the usual struct-like 'pairs' assignment is performed.

      In case resize is true, the size is computed by scanning the table for the largest numeric key.

   This means that in order to reassign only one element of a container using this system, it is necessary to use:

   { resize=false, [idx]=value }
   

Since nil inside a table is indistinguishable from missing key, it is necessary to use df.NULL as a null pointer value.

This system is intended as a way to define a nested object tree using pure lua data structures, and then materialize it in C++ memory in one go. Note that if pointer auto-vivification is used, an error in the middle of the recursive walk would not destroy any objects allocated in this way, so the user should be prepared to catch the error and do the necessary cleanup.

DFHack API

DFHack utility functions are placed in the dfhack global tree.

Native utilities

Input & Output

• dfhack.print(args...)

  Output tab-separated args as standard lua print would do, but without a newline.

• print(args...), dfhack.println(args...)

  A replacement of the standard library print function that works with DFHack output infrastructure.

• dfhack.printerr(args...)

  Same as println; intended for errors. Uses red color and logs to stderr.log.

• dfhack.color([color])

  Sets the current output color. If color is nil or -1, resets to default. Returns the previous color value.

• dfhack.is_interactive()

  Checks if the thread can access the interactive console and returns true or false.

• dfhack.lineedit([prompt[,history_filename]])

  If the thread owns the interactive console, shows a prompt and returns the entered string. Otherwise returns nil, error.

  Depending on the context, this function may actually yield the running coroutine and let the C++ code release the core suspend lock. Using an explicit dfhack.with_suspend will prevent this, forcing the function to block on input with lock held.

• dfhack.interpreter([prompt[,history_filename[,env]]])

  Starts an interactive lua interpreter, using the specified prompt string, global environment and command-line history file.

  If the interactive console is not accessible, returns nil, error.

Exception handling

• dfhack.error(msg[,level[,verbose]])

  Throws a dfhack exception object with location and stack trace. The verbose parameter controls whether the trace is printed by default.

• qerror(msg[,level])

  Calls dfhack.error() with verbose being false. Intended to be used for user-caused errors in scripts, where stack traces are not desirable.

• dfhack.pcall(f[,args...])

  Invokes f via xpcall, using an error function that attaches a stack trace to the error. The same function is used by SafeCall in C++, and dfhack.safecall.

• safecall(f[,args...]), dfhack.safecall(f[,args...])

  Just like pcall, but also prints the error using printerr before returning. Intended as a convenience function.

• dfhack.saferesume(coroutine[,args...])

  Compares to coroutine.resume like dfhack.safecall vs pcall.

• dfhack.exception

  Metatable of error objects used by dfhack. The objects have the following properties:

  err.where

  The location prefix string, or nil.

  err.message

  The base message string.

  err.stacktrace

  The stack trace string, or nil.

  err.cause

  A different exception object, or nil.

  err.thread

  The coroutine that has thrown the exception.

  err.verbose

  Boolean, or nil; specifies if where and stacktrace should be printed.

  tostring(err), or err:tostring([verbose])

  Converts the exception to string.

• dfhack.exception.verbose

  The default value of the verbose argument of err:tostring().

Miscellaneous

• dfhack.VERSION

  DFHack version string constant.

• dfhack.curry(func,args...), or curry(func,args...)

  Returns a closure that invokes the function with args combined both from the curry call and the closure call itself. I.e. curry(func,a,b)(c,d) equals func(a,b,c,d).

Locking and finalization

• dfhack.with_suspend(f[,args...])

  Calls f with arguments after grabbing the DF core suspend lock. Suspending is necessary for accessing a consistent state of DF memory.

  Returned values and errors are propagated through after releasing the lock. It is safe to nest suspends.

  Every thread is allowed only one suspend per DF frame, so it is best to group operations together in one big critical section. A plugin can choose to run all lua code inside a C++-side suspend lock.

• dfhack.call_with_finalizer(num_cleanup_args,always,cleanup_fn[,cleanup_args...],fn[,args...])

  Invokes fn with args, and after it returns or throws an error calls cleanup_fn with cleanup_args. Any return values from fn are propagated, and errors are re-thrown.

  The num_cleanup_args integer specifies the number of cleanup_args, and the always boolean specifies if cleanup should be called in any case, or only in case of an error.

• dfhack.with_finalize(cleanup_fn,fn[,args...])

  Calls fn with arguments, then finalizes with cleanup_fn. Implemented using call_with_finalizer(0,true,...).

• dfhack.with_onerror(cleanup_fn,fn[,args...])

  Calls fn with arguments, then finalizes with cleanup_fn on any thrown error. Implemented using call_with_finalizer(0,false,...).

• dfhack.with_temp_object(obj,fn[,args...])

  Calls fn(obj,args...), then finalizes with obj:delete().

Persistent configuration storage

This api is intended for storing configuration options in the world itself. It probably should be restricted to data that is world-dependent.

Entries are identified by a string key, but it is also possible to manage multiple entries with the same key; their identity is determined by entry_id. Every entry has a mutable string value, and an array of 7 mutable ints.

• dfhack.persistent.get(key), entry:get()

  Retrieves a persistent config record with the given string key, or refreshes an already retrieved entry. If there are multiple entries with the same key, it is undefined which one is retrieved by the first version of the call.

  Returns entry, or nil if not found.

• dfhack.persistent.delete(key), entry:delete()

  Removes an existing entry. Returns true if succeeded.

• dfhack.persistent.get_all(key[,match_prefix])

  Retrieves all entries with the same key, or starting with key..'/'. Calling get_all('',true) will match all entries.

  If none found, returns nil; otherwise returns an array of entries.

• dfhack.persistent.save({key=str1, ...}[,new]), entry:save([new])

  Saves changes in an entry, or creates a new one. Passing true as new forces creation of a new entry even if one already exists; otherwise the existing one is simply updated. Returns entry, did_create_new

Since the data is hidden in data structures owned by the DF world, and automatically stored in the save game, these save and retrieval functions can just copy values in memory without doing any actual I/O. However, currently every entry has a 180+-byte dead-weight overhead.

Material info lookup

A material info record has fields:

• type, index, material

  DF material code pair, and a reference to the material object.

• mode

  One of 'builtin', 'inorganic', 'plant', 'creature'.

• inorganic, plant, creature

  If the material is of the matching type, contains a reference to the raw object.

• figure

  For a specific creature material contains a ref to the historical figure.

Functions:

• dfhack.matinfo.decode(type,index)

  Looks up material info for the given number pair; if not found, returs nil.

• ....decode(matinfo), ....decode(item), ....decode(obj)

  Uses matinfo.type/matinfo.index, item getter vmethods, or obj.mat_type/obj.mat_index to get the code pair.

• dfhack.matinfo.find(token[,token...])

  Looks up material by a token string, or a pre-split string token sequence.

• dfhack.matinfo.getToken(...), info:getToken()

  Applies decode and constructs a string token.

• info:toString([temperature[,named]])

  Returns the human-readable name at the given temperature.

• info:getCraftClass()

  Returns the classification used for craft skills.

• info:matches(obj)

  Checks if the material matches job_material_category or job_item. Accept dfhack_material_category auto-assign table.

C++ function wrappers

Thin wrappers around C++ functions, similar to the ones for virtual methods. One notable difference is that these explicit wrappers allow argument count adjustment according to the usual lua rules, so trailing false/nil arguments can be omitted.

• dfhack.getOSType()

  Returns the OS type string from symbols.xml.

• dfhack.getDFVersion()

  Returns the DF version string from symbols.xml.

• dfhack.getDFPath()

  Returns the DF directory path.

• dfhack.getHackPath()

  Returns the dfhack directory path, i.e. ".../df/hack/".

• dfhack.getTickCount()

  Returns the tick count in ms, exactly as DF ui uses.

• dfhack.isWorldLoaded()

  Checks if the world is loaded.

• dfhack.isMapLoaded()

  Checks if the world and map are loaded.

• dfhack.TranslateName(name[,in_english,only_last_name])

  Convert a language_name or only the last name part to string.

Gui module

• dfhack.gui.getCurViewscreen([skip_dismissed])

  Returns the topmost viewscreen. If skip_dismissed is true, ignores screens already marked to be removed.

• dfhack.gui.getFocusString(viewscreen)

  Returns a string representation of the current focus position in the ui. The string has a "screen/foo/bar/baz..." format.

• dfhack.gui.getCurFocus([skip_dismissed])

  Returns the focus string of the current viewscreen.

• dfhack.gui.getSelectedWorkshopJob([silent])

  When a job is selected in 'q' mode, returns the job, else prints error unless silent and returns nil.

• dfhack.gui.getSelectedJob([silent])

  Returns the job selected in a workshop or unit/jobs screen.

• dfhack.gui.getSelectedUnit([silent])

  Returns the unit selected via 'v', 'k', unit/jobs, or a full-screen item view of a cage or suchlike.

• dfhack.gui.getSelectedItem([silent])

  Returns the item selected via 'v' ->inventory, 'k', 't', or a full-screen item view of a container. Note that in the last case, the highlighted contained item is returned, not the container itself.

• dfhack.gui.getSelectedBuilding([silent])

  Returns the building selected via 'q', 't', 'k' or 'i'.

• dfhack.gui.showAnnouncement(text,color[,is_bright])

  Adds a regular announcement with given text, color, and brightness. The is_bright boolean actually seems to invert the brightness.

• dfhack.gui.showZoomAnnouncement(type,pos,text,color[,is_bright])

  Like above, but also specifies a position you can zoom to from the announcement menu.

• dfhack.gui.showPopupAnnouncement(text,color[,is_bright])

  Pops up a titan-style modal announcement window.

• dfhack.gui.showAutoAnnouncement(type,pos,text,color[,is_bright])

  Uses the type to look up options from announcements.txt, and calls the above operations accordingly. If enabled, pauses and zooms to position.

Job module

• dfhack.job.cloneJobStruct(job)

  Creates a deep copy of the given job.

• dfhack.job.printJobDetails(job)

  Prints info about the job.

• dfhack.job.printItemDetails(jobitem,idx)

  Prints info about the job item.

• dfhack.job.getHolder(job)

  Returns the building holding the job.

• dfhack.job.getWorker(job)

  Returns the unit performing the job.

• dfhack.job.checkBuildingsNow()

  Instructs the game to check buildings for jobs next frame and assign workers.

• dfhack.job.checkDesignationsNow()

  Instructs the game to check designations for jobs next frame and assign workers.

• dfhack.job.is_equal(job1,job2)

  Compares important fields in the job and nested item structures.

• dfhack.job.is_item_equal(job_item1,job_item2)

  Compares important fields in the job item structures.

• dfhack.job.listNewlyCreated(first_id)

  Returns the current value of df.global.job_next_id, and if there are any jobs with first_id <= id < job_next_id, a lua list containing them.

Units module

• dfhack.units.getPosition(unit)

  Returns true x,y,z of the unit, or nil if invalid; may be not equal to unit.pos if caged.

• dfhack.units.getContainer(unit)

  Returns the container (cage) item or nil.

• dfhack.units.setNickname(unit,nick)

  Sets the unit's nickname properly.

• dfhack.units.getVisibleName(unit)

  Returns the language_name object visible in game, accounting for false identities.

• dfhack.units.getIdentity(unit)

  Returns the false identity of the unit if it has one, or nil.

• dfhack.units.getNemesis(unit)

  Returns the nemesis record of the unit if it has one, or nil.

• dfhack.units.isHidingCurse(unit)

  Checks if the unit hides improved attributes from its curse.

• dfhack.units.getPhysicalAttrValue(unit, attr_type)

• dfhack.units.getMentalAttrValue(unit, attr_type)

  Computes the effective attribute value, including curse effect.

• dfhack.units.isCrazed(unit)

• dfhack.units.isOpposedToLife(unit)

• dfhack.units.hasExtravision(unit)

• dfhack.units.isBloodsucker(unit)

  Simple checks of caste attributes that can be modified by curses.

• dfhack.units.getMiscTrait(unit, type[, create])

  Finds (or creates if requested) a misc trait object with the given id.

• dfhack.units.isDead(unit)

  The unit is completely dead and passive, or a ghost.

• dfhack.units.isAlive(unit)

  The unit isn't dead or undead.

• dfhack.units.isSane(unit)

  The unit is capable of rational action, i.e. not dead, insane, zombie, or active werewolf.

• dfhack.units.isDwarf(unit)

  The unit is of the correct race of the fortress.

• dfhack.units.isCitizen(unit)

  The unit is an alive sane citizen of the fortress; wraps the same checks the game uses to decide game-over by extinction.

• dfhack.units.getAge(unit[,true_age])

  Returns the age of the unit in years as a floating-point value. If true_age is true, ignores false identities.

• dfhack.units.getEffectiveSkill(unit, skill)

  Computes the effective rating for the given skill, taking into account exhaustion, pain etc.

• dfhack.units.computeMovementSpeed(unit)

  Computes number of frames * 100 it takes the unit to move in its current state of mind and body.

• dfhack.units.getNoblePositions(unit)

  Returns a list of tables describing noble position assignments, or nil. Every table has fields entity, assignment and position.

• dfhack.units.getProfessionName(unit[,ignore_noble,plural])

  Retrieves the profession name using custom profession, noble assignments or raws. The ignore_noble boolean disables the use of noble positions.

• dfhack.units.getCasteProfessionName(race,caste,prof_id[,plural])

  Retrieves the profession name for the given race/caste using raws.

• dfhack.units.getProfessionColor(unit[,ignore_noble])

  Retrieves the color associated with the profession, using noble assignments or raws. The ignore_noble boolean disables the use of noble positions.

• dfhack.units.getCasteProfessionColor(race,caste,prof_id)

  Retrieves the profession color for the given race/caste using raws.

Items module

• dfhack.items.getPosition(item)

  Returns true x,y,z of the item, or nil if invalid; may be not equal to item.pos if in inventory.

• dfhack.items.getDescription(item, type[, decorate])

  Returns the string description of the item, as produced by the getItemDescription method. If decorate is true, also adds markings for quality and improvements.

• dfhack.items.getGeneralRef(item, type)

  Searches for a general_ref with the given type.

• dfhack.items.getSpecificRef(item, type)

  Searches for a specific_ref with the given type.

• dfhack.items.getOwner(item)

  Returns the owner unit or nil.

• dfhack.items.setOwner(item,unit)

  Replaces the owner of the item. If unit is nil, removes ownership. Returns false in case of error.

• dfhack.items.getContainer(item)

  Returns the container item or nil.

• dfhack.items.getContainedItems(item)

  Returns a list of items contained in this one.

• dfhack.items.moveToGround(item,pos)

  Move the item to the ground at position. Returns false if impossible.

• dfhack.items.moveToContainer(item,container)

  Move the item to the container. Returns false if impossible.

• dfhack.items.moveToBuilding(item,building,use_mode)

  Move the item to the building. Returns false if impossible.

• dfhack.items.moveToInventory(item,unit,use_mode,body_part)

  Move the item to the unit inventory. Returns false if impossible.

• dfhack.items.remove(item[, no_uncat])

  Removes the item, and marks it for garbage collection unless no_uncat is true.

• dfhack.items.makeProjectile(item)

  Turns the item into a projectile, and returns the new object, or nil if impossible.

Maps module

• dfhack.maps.getSize()

  Returns map size in blocks: x, y, z

• dfhack.maps.getTileSize()

  Returns map size in tiles: x, y, z

• dfhack.maps.getBlock(x,y,z)

  Returns a map block object for given x,y,z in local block coordinates.

• dfhack.maps.isValidTilePos(coords), or isValidTilePos(x,y,z)``

  Checks if the given df::coord or x,y,z in local tile coordinates are valid.

• dfhack.maps.getTileBlock(coords), or getTileBlock(x,y,z)

  Returns a map block object for given df::coord or x,y,z in local tile coordinates.

• dfhack.maps.ensureTileBlock(coords), or ensureTileBlock(x,y,z)

  Like getTileBlock, but if the block is not allocated, try creating it.

• dfhack.maps.getRegionBiome(region_coord2d), or getRegionBiome(x,y)

  Returns the biome info struct for the given global map region.

• dfhack.maps.enableBlockUpdates(block[,flow,temperature])

  Enables updates for liquid flow or temperature, unless already active.

• dfhack.maps.spawnFlow(pos,type,mat_type,mat_index,dimension)

  Spawns a new flow (i.e. steam/mist/dust/etc) at the given pos, and with the given parameters. Returns it, or nil if unsuccessful.

• dfhack.maps.getGlobalInitFeature(index)

  Returns the global feature object with the given index.

• dfhack.maps.getLocalInitFeature(region_coord2d,index)

  Returns the local feature object with the given region coords and index.

• dfhack.maps.getTileBiomeRgn(coords), or getTileBiomeRgn(x,y,z)

  Returns x, y for use with getRegionBiome.

• dfhack.maps.canWalkBetween(pos1, pos2)

  Checks if a dwarf may be able to walk between the two tiles, using a pathfinding cache maintained by the game. Note that this cache is only updated when the game is unpaused, and thus can get out of date if doors are forbidden or unforbidden, or tools like liquids or tiletypes are used. It also cannot possibly take into account anything that depends on the actual units, like burrows, or the presence of invaders.

Burrows module

• dfhack.burrows.findByName(name)

  Returns the burrow pointer or nil.

• dfhack.burrows.clearUnits(burrow)

  Removes all units from the burrow.

• dfhack.burrows.isAssignedUnit(burrow,unit)

  Checks if the unit is in the burrow.

• dfhack.burrows.setAssignedUnit(burrow,unit,enable)

  Adds or removes the unit from the burrow.

• dfhack.burrows.clearTiles(burrow)

  Removes all tiles from the burrow.

• dfhack.burrows.listBlocks(burrow)

  Returns a table of map block pointers.

• dfhack.burrows.isAssignedTile(burrow,tile_coord)

  Checks if the tile is in burrow.

• dfhack.burrows.setAssignedTile(burrow,tile_coord,enable)

  Adds or removes the tile from the burrow. Returns false if invalid coords.

• dfhack.burrows.isAssignedBlockTile(burrow,block,x,y)

  Checks if the tile within the block is in burrow.

• dfhack.burrows.setAssignedBlockTile(burrow,block,x,y,enable)

  Adds or removes the tile from the burrow. Returns false if invalid coords.

Buildings module

• dfhack.buildings.setOwner(item,unit)

  Replaces the owner of the building. If unit is nil, removes ownership. Returns false in case of error.

• dfhack.buildings.getSize(building)

  Returns width, height, centerx, centery.

• dfhack.buildings.findAtTile(pos), or findAtTile(x,y,z)

  Scans the buildings for the one located at the given tile. Does not work on civzones. Warning: linear scan if the map tile indicates there are buildings at it.

• dfhack.buildings.findCivzonesAt(pos), or findCivzonesAt(x,y,z)

  Scans civzones, and returns a lua sequence of those that touch the given tile, or nil if none.

• dfhack.buildings.getCorrectSize(width, height, type, subtype, custom, direction)

  Computes correct dimensions for the specified building type and orientation, using width and height for flexible dimensions. Returns is_flexible, width, height, center_x, center_y.

• dfhack.buildings.checkFreeTiles(pos,size[,extents,change_extents,allow_occupied])

  Checks if the rectangle defined by pos and size, and possibly extents, can be used for placing a building. If change_extents is true, bad tiles are removed from extents. If allow_occupied, the occupancy test is skipped.

• dfhack.buildings.countExtentTiles(extents,defval)

  Returns the number of tiles included by extents, or defval.

• dfhack.buildings.containsTile(building, x, y[, room])

  Checks if the building contains the specified tile, either directly, or as room.

• dfhack.buildings.hasSupport(pos,size)

  Checks if a bridge constructed at specified position would have support from terrain, and thus won't collapse if retracted.

Low-level building creation functions;

• dfhack.buildings.allocInstance(pos, type, subtype, custom)

  Creates a new building instance of given type, subtype and custom type, at specified position. Returns the object, or nil in case of an error.

• dfhack.buildings.setSize(building, width, height, direction)

  Configures an object returned by allocInstance, using specified parameters wherever appropriate. If the building has fixed size along any dimension, the corresponding input parameter will be ignored. Returns false if the building cannot be placed, or true, width, height, rect_area, true_area. Returned width and height are the final values used by the building; true_area is less than rect_area if any tiles were removed from designation.

• dfhack.buildings.constructAbstract(building)

  Links a fully configured object created by allocInstance into the world. The object must be an abstract building, i.e. a stockpile or civzone. Returns true, or false if impossible.

• dfhack.buildings.constructWithItems(building, items)

  Links a fully configured object created by allocInstance into the world for construction, using a list of specific items as material. Returns true, or false if impossible.

• dfhack.buildings.constructWithFilters(building, job_items)

  Links a fully configured object created by allocInstance into the world for construction, using a list of job_item filters as inputs. Returns true, or false if impossible. Filter objects are claimed and possibly destroyed in any case. Use a negative quantity field value to auto-compute the amount from the size of the building.

• dfhack.buildings.deconstruct(building)

  Destroys the building, or queues a deconstruction job. Returns true if the building was destroyed and deallocated immediately.

More high-level functions are implemented in lua and can be loaded by require('dfhack.buildings'). See hack/lua/dfhack/buildings.lua.

Among them are:

• dfhack.buildings.getFiltersByType(argtable,type,subtype,custom)

  Returns a sequence of lua structures, describing input item filters suitable for the specified building type, or nil if unknown or invalid. The returned sequence is suitable for use as the job_items argument of constructWithFilters. Uses tables defined in buildings.lua.

  Argtable members material (the default name), bucket, barrel, chain, mechanism, screw, pipe, anvil, weapon are used to augment the basic attributes with more detailed information if the building has input items with the matching name (see the tables for naming details). Note that it is impossible to override any properties this way, only supply those that are not mentioned otherwise; one exception is that flags2.non_economic is automatically cleared if an explicit material is specified.

• dfhack.buildings.constructBuilding{...}

  Creates a building in one call, using options contained in the argument table. Returns the building, or nil, error.

  NOTE: Despite the name, unless the building is abstract, the function creates it in an 'unconstructed' stage, with a queued in-game job that will actually construct it. I.e. the function replicates programmatically what can be done through the construct building menu in the game ui, except that it does less environment constraint checking.

  The following options can be used:

  • pos = coordinates, or x = ..., y = ..., z = ...

    Mandatory. Specifies the left upper corner of the building.

  • type = df.building_type.FOO, subtype = ..., custom = ...

    Mandatory. Specifies the type of the building. Obviously, subtype and custom are only expected if the type requires them.

  • fields = { ... }

    Initializes fields of the building object after creation with df.assign.

  • width = ..., height = ..., direction = ...

    Sets size and orientation of the building. If it is fixed-size, specified dimensions are ignored.

  • full_rectangle = true

    For buildings like stockpiles or farm plots that can normally accomodate individual tile exclusion, forces an error if any tiles within the specified width*height are obstructed.

  • items = { item, item ... }, or filters = { {...}, {...}... }

    Specifies explicit items or item filters to use in construction. It is the job of the user to ensure they are correct for the building type.

  • abstract = true

    Specifies that the building is abstract and does not require construction. Required for stockpiles and civzones; an error otherwise.

  • material = {...}, mechanism = {...}, ...

    If none of items, filter, or abstract is used, the function uses getFiltersByType to compute the input item filters, and passes the argument table through. If no filters can be determined this way, constructBuilding throws an error.

Constructions module

• dfhack.constructions.designateNew(pos,type,item_type,mat_index)

  Designates a new construction at given position. If there already is a planned but not completed construction there, changes its type. Returns true, or false if obstructed. Note that designated constructions are technically buildings.

• dfhack.constructions.designateRemove(pos), or designateRemove(x,y,z)

  If there is a construction or a planned construction at the specified coordinates, designates it for removal, or instantly cancels the planned one. Returns true, was_only_planned if removed; or false if none found.

Screen API

The screen module implements support for drawing to the tiled screen of the game. Note that drawing only has any effect when done from callbacks, so it can only be feasibly used in the core context.

Basic painting functions:

• dfhack.screen.getWindowSize()

  Returns width, height of the screen.

• dfhack.screen.getMousePos()

  Returns x,y of the tile the mouse is over.

• dfhack.screen.inGraphicsMode()

  Checks if [GRAPHICS:YES] was specified in init.

• dfhack.screen.paintTile(pen,x,y[,char,tile])

  Paints a tile using given parameters. Pen is a table with following possible fields:

  ch

  Provides the ordinary tile character, as either a 1-character string or a number. Can be overridden with the char function parameter.

  fg

  Foreground color for the ordinary tile. Defaults to COLOR_GREY (7).

  bg

  Background color for the ordinary tile. Defaults to COLOR_BLACK (0).

  bold

  Bright/bold text flag. If nil, computed based on (fg & 8); fg is masked to 3 bits. Otherwise should be true/false.

  tile

  Graphical tile id. Ignored unless [GRAPHICS:YES] was in init.txt.

  tile_color = true

  Specifies that the tile should be shaded with fg/bg.

  tile_fg, tile_bg

  If specified, overrides tile_color and supplies shading colors directly.

  Returns false if coordinates out of bounds, or other error.

• dfhack.screen.readTile(x,y)

  Retrieves the contents of the specified tile from the screen buffers. Returns a pen, or nil if invalid or TrueType.

• dfhack.screen.paintString(pen,x,y,text)

  Paints the string starting at x,y. Uses the string characters in sequence to override the ch field of pen.

  Returns true if painting at least one character succeeded.

• dfhack.screen.fillRect(pen,x1,y1,x2,y2)

  Fills the rectangle specified by the coordinates with the given pen. Returns true if painting at least one character succeeded.

• dfhack.screen.findGraphicsTile(pagename,x,y)

  Finds a tile from a graphics set (i.e. the raws used for creatures), if in graphics mode and loaded.

  Returns: tile, tile_grayscale, or nil if not found. The values can then be used for the tile field of pen structures.

• dfhack.screen.clear()

  Fills the screen with blank background.

• dfhack.screen.invalidate()

  Requests repaint of the screen by setting a flag. Unlike other functions in this section, this may be used at any time.

In order to actually be able to paint to the screen, it is necessary to create and register a viewscreen (basically a modal dialog) with the game.

NOTE: As a matter of policy, in order to avoid user confusion, all interface screens added by dfhack should bear the "DFHack" signature.

Screens are managed with the following functions:

• dfhack.screen.show(screen[,below])

  Displays the given screen, possibly placing it below a different one. The screen must not be already shown. Returns true if success.

• dfhack.screen.dismiss(screen[,to_first])

  Marks the screen to be removed when the game enters its event loop. If to_first is true, all screens up to the first one will be deleted.

• dfhack.screen.isDismissed(screen)

  Checks if the screen is already marked for removal.

Apart from a native viewscreen object, these functions accept a table as a screen. In this case, show creates a new native viewscreen that delegates all processing to methods stored in that table.

NOTE: Lua-implemented screens are only supported in the core context.

Supported callbacks and fields are:

• screen._native

  Initialized by show with a reference to the backing viewscreen object, and removed again when the object is deleted.

• function screen:onShow()

  Called by dfhack.screen.show if successful.

• function screen:onDismiss()

  Called by dfhack.screen.dismiss if successful.

• function screen:onDestroy()

  Called from the destructor when the viewscreen is deleted.

• function screen:onResize(w, h)

  Called before onRender or onIdle when the window size has changed.

• function screen:onRender()

  Called when the viewscreen should paint itself. This is the only context where the above painting functions work correctly.

  If omitted, the screen is cleared; otherwise it should do that itself. In order to make a see-through dialog, call self._native.parent:render().

• function screen:onIdle()

  Called every frame when the screen is on top of the stack.

• function screen:onHelp()

  Called when the help keybinding is activated (usually '?').

• function screen:onInput(keys)

  Called when keyboard or mouse events are available. If any keys are pressed, the keys argument is a table mapping them to true. Note that this refers to logical keybingings computed from real keys via options; if multiple interpretations exist, the table will contain multiple keys.

  The table also may contain special keys:

  _STRING

  Maps to an integer in range 0-255. Duplicates a separate "STRING_A???" code for convenience.

  _MOUSE_L, _MOUSE_R

  If the left or right mouse button is pressed.

  If this method is omitted, the screen is dismissed on receival of the LEAVESCREEN key.

• function screen:onGetSelectedUnit()

• function screen:onGetSelectedItem()

• function screen:onGetSelectedJob()

• function screen:onGetSelectedBuilding()

  Implement these to provide a return value for the matching dfhack.gui.getSelected... function.

Internal API

These functions are intended for the use by dfhack developers, and are only documented here for completeness:

• dfhack.internal.scripts

  The table used by dfhack.run_script() to give every script its own global environment, persistent between calls to the script.

• dfhack.internal.getAddress(name)

  Returns the global address name, or nil.

• dfhack.internal.setAddress(name, value)

  Sets the global address name. Returns the value of getAddress before the change.

• dfhack.internal.getVTable(name)

  Returns the pre-extracted vtable address name, or nil.

• dfhack.internal.getRebaseDelta()

  Returns the ASLR rebase offset of the DF executable.

• dfhack.internal.getMemRanges()

  Returns a sequence of tables describing virtual memory ranges of the process.

• dfhack.internal.patchMemory(dest,src,count)

  Like memmove below, but works even if dest is read-only memory, e.g. code. If destination overlaps a completely invalid memory region, or another error occurs, returns false.

• dfhack.internal.memmove(dest,src,count)

  Wraps the standard memmove function. Accepts both numbers and refs as pointers.

• dfhack.internal.memcmp(ptr1,ptr2,count)

  Wraps the standard memcmp function.

• dfhack.internal.memscan(haystack,count,step,needle,nsize)

  Searches for needle of nsize bytes in haystack, using count steps of step bytes. Returns: step_idx, sum_idx, found_ptr, or nil if not found.

• dfhack.internal.diffscan(old_data, new_data, start_idx, end_idx, eltsize[, oldval, newval, delta])

  Searches for differences between buffers at ptr1 and ptr2, as integers of size eltsize. The oldval, newval or delta arguments may be used to specify additional constraints. Returns: found_index, or nil if end reached.

Core interpreter context

While plugins can create any number of interpreter instances, there is one special context managed by dfhack core. It is the only context that can receive events from DF and plugins.

Core context specific functions:

• dfhack.is_core_context

  Boolean value; true in the core context.

• dfhack.timeout(time,mode,callback)

  Arranges for the callback to be called once the specified period of time passes. The mode argument specifies the unit of time used, and may be one of 'frames' (raw FPS), 'ticks' (unpaused FPS), 'days', 'months', 'years' (in-game time). All timers other than 'frames' are cancelled when the world is unloaded, and cannot be queued until it is loaded again. Returns the timer id, or nil if unsuccessful due to world being unloaded.

• dfhack.timeout_active(id[,new_callback])

  Returns the active callback with the given id, or nil if inactive or nil id. If called with 2 arguments, replaces the current callback with the given value, if still active. Using timeout_active(id,nil) cancels the timer.

• dfhack.onStateChange.foo = function(code)

  Event. Receives the same codes as plugin_onstatechange in C++.

Event type

An event is a native object transparently wrapping a lua table, and implementing a __call metamethod. When it is invoked, it loops through the table with next and calls all contained values. This is intended as an extensible way to add listeners.

This type itself is available in any context, but only the core context has the actual events defined by C++ code.

Features:

• dfhack.event.new()

  Creates a new instance of an event.

• event[key] = function

  Sets the function as one of the listeners. Assign nil to remove it.

  NOTE: The df.NULL key is reserved for the use by the C++ owner of the event; it is an error to try setting it.

• #event

  Returns the number of non-nil listeners.

• pairs(event)

  Iterates over all listeners in the table.

• event(args...)

  Invokes all listeners contained in the event in an arbitrary order using dfhack.safecall.

Lua Modules

DFHack sets up the lua interpreter so that the built-in require function can be used to load shared lua code from hack/lua/. The dfhack namespace reference itself may be obtained via require('dfhack'), although it is initially created as a global by C++ bootstrap code.

The following module management functions are provided:

• mkmodule(name)

  Creates an environment table for the module. Intended to be used as:

  local _ENV = mkmodule('foo')
  ...
  return _ENV
  

  If called the second time, returns the same table; thus providing reload support.

• reload(name)

  Reloads a previously require-d module "name" from the file. Intended as a help for module development.

• dfhack.BASE_G

  This variable contains the root global environment table, which is used as a base for all module and script environments. Its contents should be kept limited to the standard Lua library and API described in this document.

Global environment

A number of variables and functions are provided in the base global environment by the mandatory init file dfhack.lua:

• Color constants

  These are applicable both for dfhack.color() and color fields in DF functions or structures:

  COLOR_RESET, COLOR_BLACK, COLOR_BLUE, COLOR_GREEN, COLOR_CYAN, COLOR_RED, COLOR_MAGENTA, COLOR_BROWN, COLOR_GREY, COLOR_DARKGREY, COLOR_LIGHTBLUE, COLOR_LIGHTGREEN, COLOR_LIGHTCYAN, COLOR_LIGHTRED, COLOR_LIGHTMAGENTA, COLOR_YELLOW, COLOR_WHITE

• dfhack.onStateChange event codes

  Available only in the core context, as is the event itself:

  SC_WORLD_LOADED, SC_WORLD_UNLOADED, SC_MAP_LOADED, SC_MAP_UNLOADED, SC_VIEWSCREEN_CHANGED, SC_CORE_INITIALIZED

• Functions already described above

  safecall, qerror, mkmodule, reload

• printall(obj)

  If the argument is a lua table or DF object reference, prints all fields.

• copyall(obj)

  Returns a shallow copy of the table or reference as a lua table.

• pos2xyz(obj)

  The object must have fields x, y and z. Returns them as 3 values. If obj is nil, or x is -30000 (the usual marker for undefined coordinates), returns nil.

• xyz2pos(x,y,z)

  Returns a table with x, y and z as fields.

• safe_index(obj,index...)

  Walks a sequence of dereferences, which may be represented by numbers or strings. Returns nil if any of obj or indices is nil, or a numeric index is out of array bounds.

utils

• utils.compare(a,b)

  Comparator function; returns -1 if a<b, 1 if a>b, 0 otherwise.

• utils.compare_name(a,b)

  Comparator for names; compares empty string last.

• utils.is_container(obj)

  Checks if obj is a container ref.

• utils.make_index_sequence(start,end)

  Returns a lua sequence of numbers in start..end.

• utils.make_sort_order(data, ordering)

  Computes a sorted permutation of objects in data, as a table of integer indices into the data sequence. Uses data.n as input length if present.

  The ordering argument is a sequence of ordering specs, represented as lua tables with following possible fields:

  ord.key = function(value)

  Computes comparison key from input data value. Not called on nil. If omitted, the comparison key is the value itself.

  ord.key_table = function(data)

  Computes a key table from the data table in one go.

  ord.compare = function(a,b)

  Comparison function. Defaults to utils.compare above. Called on non-nil keys; nil sorts last.

  ord.nil_first = true/false

  If true, nil keys are sorted first instead of last.

  ord.reverse = true/false

  If true, sort non-nil keys in descending order.

  For every comparison during sorting the specs are applied in order until an unambiguous decision is reached. Sorting is stable.

  Example of sorting a sequence by field foo:

  local spec = { key = function(v) return v.foo end }
  local order = utils.make_sort_order(data, { spec })
  local output = {}
  for i = 1,#order do output[i] = data[order[i]] end
  

  Separating the actual reordering of the sequence in this way enables applying the same permutation to multiple arrays. This function is used by the sort plugin.

• utils.assign(tgt, src)

  Does a recursive assignment of src into tgt. Uses df.assign if tgt is a native object ref; otherwise recurses into lua tables.

• utils.clone(obj, deep)

  Performs a shallow, or semi-deep copy of the object as a lua table tree. The deep mode recurses into lua tables and subobjects, except pointers to other heap objects. Null pointers are represented as df.NULL. Zero-based native containers are converted to 1-based lua sequences.

• utils.clone_with_default(obj, default, force)

  Copies the object, using the default lua table tree as a guide to which values should be skipped as uninteresting. The force argument makes it always return a non-nil value.

• utils.sort_vector(vector,field,cmpfun)

  Sorts a native vector or lua sequence using the comparator function. If field is not nil, applies the comparator to the field instead of the whole object.

• utils.binsearch(vector,key,field,cmpfun,min,max)

  Does a binary search in a native vector or lua sequence for key, using cmpfun and field like sort_vector. If min and max are specified, they are used as the search subrange bounds.

  If found, returns item, true, idx. Otherwise returns nil, false, insert_idx, where insert_idx is the correct insertion point.

• utils.insert_sorted(vector,item,field,cmpfun)

  Does a binary search, and inserts item if not found. Returns did_insert, vector[idx], idx.

• utils.insert_or_update(vector,item,field,cmpfun)

  Like insert_sorted, but also assigns the item into the vector cell if insertion didn't happen.

  As an example, you can use this to set skill values:

  utils.insert_or_update(soul.skills, {new=true, id=..., rating=...}, 'id')
  

  (For an explanation of new=true, see table assignment in the wrapper section)

• utils.prompt_yes_no(prompt, default)

  Presents a yes/no prompt to the user. If default is not nil, allows just pressing Enter to submit the default choice. If the user enters 'abort', throws an error.

• utils.prompt_input(prompt, checkfun, quit_str)

  Presents a prompt to input data, until a valid string is entered. Once checkfun(input) returns true, ..., passes the values through. If the user enters the quit_str (defaults to '~~~'), throws an error.

• utils.check_number(text)

  A prompt_input checkfun that verifies a number input.

dumper

A third-party lua table dumper module from http://lua-users.org/wiki/DataDumper. Defines one function:

• dumper.DataDumper(value, varname, fastmode, ident, indent_step)

  Returns value converted to a string. The indent_step argument specifies the indentation step size in spaces. For the other arguments see the original documentation link above.

class

Implements a trivial single-inheritance class system.

• Foo = defclass(Foo[, ParentClass])

  Defines or updates class Foo. The Foo = defclass(Foo) syntax is needed so that when the module or script is reloaded, the class identity will be preserved through the preservation of global variable values.

  The defclass function is defined as a stub in the global namespace, and using it will auto-load the class module.

• Class.super

  This class field is set by defclass to the parent class, and allows a readable Class.super.method(self, ...) syntax for calling superclass methods.

• Class.ATTRS { foo = xxx, bar = yyy }

  Declares certain instance fields to be attributes, i.e. auto-initialized from fields in the table used as the constructor argument. If omitted, they are initialized with the default values specified in this declaration.

  If the default value should be nil, use ATTRS { foo = DEFAULT_NIL }.

• new_obj = Class{ foo = arg, bar = arg, ... }

  Calling the class as a function creates and initializes a new instance. Initialization happens in this order:

  1. An empty instance table is created, and its metatable set.
  2. The preinit method is called via invoke_before (see below) with the table used as argument to the class. This method is intended for validating and tweaking that argument table.
  3. Declared ATTRS are initialized from the argument table or their default values.
  4. The init method is called via invoke_after with the argument table. This is the main constructor method.
  5. The postinit method is called via invoke_after with the argument table. Place code that should be called after the object is fully constructed here.

Predefined instance methods:

• instance:assign{ foo = xxx }

  Assigns all values in the input table to the matching instance fields.

• instance:callback(method_name, [args...])

  Returns a closure that invokes the specified method of the class, properly passing in self, and optionally a number of initial arguments too. The arguments given to the closure are appended to these.

• instance:invoke_before(method_name, args...)

  Navigates the inheritance chain of the instance starting from the most specific class, and invokes the specified method with the arguments if it is defined in that specific class. Equivalent to the following definition in every class:

  function Class:invoke_before(method, ...)
    if rawget(Class, method) then
      rawget(Class, method)(self, ...)
    end
    Class.super.invoke_before(method, ...)
  end
  

• instance:invoke_after(method_name, args...)

  Like invoke_before, only the method is called after the recursive call to super, i.e. invocations happen in the parent to child order.

  These two methods are inspired by the Common Lisp before and after methods, and are intended for implementing similar protocols for certain things. The class library itself uses them for constructors.

To avoid confusion, these methods cannot be redefined.

Plugins

DFHack plugins may export native functions and events to lua contexts. They are automatically imported by mkmodule('plugins.<name>'); this means that a lua module file is still necessary for require to read.

The following plugins have lua support.

burrows

Implements extended burrow manipulations.

Events:

• onBurrowRename.foo = function(burrow)

  Emitted when a burrow might have been renamed either through the game UI, or renameBurrow().

• onDigComplete.foo = function(job_type,pos,old_tiletype,new_tiletype,worker)

  Emitted when a tile might have been dug out. Only tracked if the auto-growing burrows feature is enabled.

Native functions:

• renameBurrow(burrow,name)

  Renames the burrow, emitting onBurrowRename and updating auto-grow state properly.

• findByName(burrow,name)

  Finds a burrow by name, using the same rules as the plugin command line interface. Namely, trailing '+' characters marking auto-grow burrows are ignored.

• copyUnits(target,source,enable)

  Applies units from source burrow to target. The enable parameter specifies if they are to be added or removed.

• copyTiles(target,source,enable)

  Applies tiles from source burrow to target. The enable parameter specifies if they are to be added or removed.

• setTilesByKeyword(target,keyword,enable)

  Adds or removes tiles matching a predefined keyword. The keyword set is the same as used by the command line.

The lua module file also re-exports functions from dfhack.burrows.

sort

Does not export any native functions as of now. Instead, it calls lua code to perform the actual ordering of list items.

Scripts

Any files with the .lua extension placed into hack/scripts/* are automatically used by the DFHack core as commands. The matching command name consists of the name of the file sans the extension.

If the first line of the script is a one-line comment, it is used by the built-in ls and help commands.

NOTE: Scripts placed in subdirectories still can be accessed, but do not clutter the ls command list; thus it is preferred for obscure developer-oriented scripts and scripts used by tools. When calling such scripts, always use '/' as the separator for directories, e.g. devel/lua-example.

Scripts are re-read from disk every time they are used (this may be changed later to check the file change time); however the global variable values persist in memory between calls. Every script gets its own separate environment for global variables.

Arguments are passed in to the scripts via the ... built-in quasi-variable; when the script is called by the DFHack core, they are all guaranteed to be non-nil strings.

DFHack core invokes the scripts in the core context (see above); however it is possible to call them from any lua code (including from other scripts) in any context, via the same function the core uses:

• dfhack.run_script(name[,args...])

  Run a lua script in hack/scripts/, as if it was started from dfhack command-line. The name argument should be the name stem, as would be used on the command line.

Note that this function lets errors propagate to the caller.