This document describes how to use the main Anselme modules. This is generated automatically from the source files.

Note that this file only describes the anselme and state.State modules, as well as the TextEventData and ChoiceEventData classes, which are only a selection of what I consider to be the "public API" of Anselme that I will try to keep stable. If you need more advanced control on Anselme, feel free to look into the other source files to find more; the most useful functions should all be reasonably commented.

anselme

The main module.

Usage:

local anselme = require("anselme")

-- create a new state
local state = anselme.new()
state:load_stdlib()

-- load an anselme script file in a new branch
local run_state = state:branch()
run_state:run_file("script.ans")

-- run the script
while run_state:active() do
	local event, data = run_state:step()
	if event == "text" then
		for _, l in ipairs(data) do
			print(l)
		end
	elseif event == "choice" then
		for i, l in ipairs(data) do
			print(("%s> %s"):format(i, l))
		end
		local choice = tonumber(io.read("l"))
		data:choose(choice)
	elseif event == "return" then
		run_state:merge()
	elseif event == "error" then
		error(data)
	end
end

If require("anselme") fails with an error similar to module 'anselme' not found, you might need to redefine package.path before the require:

package.path = "path/?/init.lua;path/?.lua;" .. package.path -- where path is the directory where anselme is located
require("anselme")

Anselme expects that require("anselme.module") will try loading both anselme/module/init.lua and anselme/module.lua, which may not be the case without the above code as package.path's default value is system dependent, i.e. not my problem.

.version

Global version string. Follow semver.

defined at line 53 of anselme/init.lua: version = "2.0.0-rc1",

.versions

Table containing per-category version numbers. Incremented by one for any change that may break compatibility.

defined at line 56 of anselme/init.lua: versions = {

.language

Version number for language and standard library changes.

defined at line 58 of anselme/init.lua: language = 31,

.save

Version number for save/AST format changes.

defined at line 60 of anselme/init.lua: save = 7,

.api

Version number for Lua API changes.

defined at line 62 of anselme/init.lua: api = 10

.parse (code, source)

Parse a code string and return the generated AST.

source is an optional string; it will be used as the code source name in error messages.

Usage:

local ast = anselme.parse("1 + 2", "test")
ast:eval(state)

defined at line 74 of anselme/init.lua: parse = function(code, source)

.parse_file (path)

Same as :parse, but reads the code from a file. source will be set as the file path.

defined at line 79 of anselme/init.lua: parse_file = function(path)

.generate_translation_template (code, source)

Generates and return Anselme code (as a string) that can be used as a base for a translation file. This will include every translatable element found in this code. source is an optional string; it will be used as the code source name in translation contexts.

defined at line 88 of anselme/init.lua: generate_translation_template = function(code, source)

.generate_translation_template_file (path)

Same as :generate_translation_template, but reads the code from a file. source will be set as the file path.

defined at line 93 of anselme/init.lua: generate_translation_template_file = function(path)

.new ()

Return a new State.

defined at line 97 of anselme/init.lua: new = function()

State

Contains all state relative to an Anselme interpreter. Each State is fully independant from each other. Each State can run a single script at a time, and variable changes are isolated between each State (see branching).

:load_stdlib (language)

Load standard library. You will probably want to call this on every State right after creation.

Optionally, you can specify language (string) to instead load a translated version of the standaring library. Available translations:

"frFR"

defined at line 48 of anselme/state/State.lua: load_stdlib = function(self, language)

Branching and merging

.branch_id

Name of the branch associated to this State.

defined at line 76 of anselme/state/State.lua: branch_id = "main",

.source_branch

State this State was branched from. nil if this is the main branch.

defined at line 78 of anselme/state/State.lua: source_branch = nil,

:branch (branch_id)

Return a new branch of this State.

Branches act as indepent copies of this State where any change will not be reflected in the source State until it is merged back into the source branch. Note: probably makes the most sense to create branches from the main State only.

defined at line 84 of anselme/state/State.lua: branch = function(self, branch_id)

:merge ()

Merge everything that was changed in this branch back into the main State branch.

Recommendation: only merge if you know that the state of the variables is consistent, for example at the end of the script, checkpoints, ... If your script errored or was interrupted at an unknown point in the script, you might be in the middle of a calculation and variables won't contain values you want to merge.

defined at line 93 of anselme/state/State.lua: merge = function(self)

Variable definition

:define (name, value, func, raw_mode)

Define a value in the global scope, converting it from Lua to Anselme if needed.

for lua functions: define("name", "(x, y, z=5)", function(x, y, z) ... end), where arguments and return values of the function are automatically converted between anselme and lua values
for other lua values: define("name", value)
for anselme AST: define("name", value)

name can be prefixed with symbol modifiers, for example "@name" for an exported variable.

If raw_mode is true, no anselme-to/from-lua conversion will be performed in the function. The function will receive the state followed by AST nodes as arguments, and is expected to return an AST node.

defined at line 111 of anselme/state/State.lua: define = function(self, name, value, func, raw_mode)

:define_local (name, value, func, raw_mode)

Same as :define, but define the expression in the current scope.

defined at line 117 of anselme/state/State.lua: define_local = function(self, name, value, func, raw_mode)

:defined (name)

Returns true if name (string) is defined in the global scope. Returns false otherwise.

defined at line 122 of anselme/state/State.lua: defined = function(self, name)

:defined_local (name)

Same as :defined, but check if the variable is defined in the current scope.

defined at line 129 of anselme/state/State.lua: defined_local = function(self, name)

For anything more advanced, you can directly access the current scope stack stored in state.scope. See state/ScopeStack.lua for details; the documentation is not as polished as this file but you should still be able to find your way around.

Saving and loading persistent variables

:save ()

Return a serialized (string) representation of all persistent variables in this State.

This can be loaded back later using :load.

defined at line 141 of anselme/state/State.lua: save = function(self)

:load (save)

Load a string generated by :save.

Variables that already exist will be overwritten with the loaded data.

defined at line 148 of anselme/state/State.lua: load = function(self, save)

Current script state

:active ()

Returns true if a script is currently loaded in this branch, false otherwise.

defined at line 163 of anselme/state/State.lua: active = function(self)

:state ()

Returns "running" if a script is currently loaded and running (i.e. this was called from the script).

Returns "active" if a script is loaded but not currently running (i.e. the script has not started or is waiting on an event).

Returns "inactive" if no script is loaded.

defined at line 171 of anselme/state/State.lua: state = function(self)

:run (code, source, tags)

Load a script in this branch. It will become the active script.

code is the code string or AST to run. If code is a string, source is the source name string to show in errors (optional). tags is an optional Lua table; its content will be added to the tags for the duration of the script.

Note that this will only load the script; execution will only start by using the :step method. Will error if a script is already active in this State.

defined at line 184 of anselme/state/State.lua: run = function(self, code, source, tags)

:run_file (path, tags)

Same as :run, but read the code from a file. source will be set as the file path.

defined at line 195 of anselme/state/State.lua: run_file = function(self, path, tags)

:step ()

When a script is active, will resume running it until the next event.

Will error if no script is active.

Returns event type string, event data.

See the events section for details on event data types for built-in events.

defined at line 208 of anselme/state/State.lua: step = function(self)

:interrupt (code, source, tags)

Stops the currently active script.

Will error if no script is active.

code, source and tags are all optional and have the same behaviour as in :run. If they are given, the script will not be disabled but instead will be immediately replaced with this new script. The new script will then be started on the next :step and will preserve the current scope. This can be used to trigger an exit function or similar in the active script.

If this is called from within a running script, this will raise an interrupt event in order to stop the current script execution.

defined at line 229 of anselme/state/State.lua: interrupt = function(self, code, source, tags)

:eval (code, source, tags)

Evaluate an expression in the global scope.

This can be called from outside a running script, but an error will be triggered the expression raise any event other than return.

code is the code string or AST to run. If code is a string, source is the source name string to show in errors (optional). tags is an optional Lua table; its content will be added to the tags for the duration of the expression.

returns AST in case of success. Run :to_lua(state) on it to convert to a Lua value.
returns nil, error message in case of error.

defined at line 256 of anselme/state/State.lua: eval = function(self, code, source, tags)

:eval_local (code, source, tags)

Same as :eval, but evaluate the expression in the current scope.

defined at line 263 of anselme/state/State.lua: eval_local = function(self, code, source, tags)

If you want to perform more advanced manipulation of the resulting AST nodes, look at the ast modules. In particular, every Node inherits the methods from ast.abstract.Node. Otherwise, each Node has its own module file defined in the ast/ directory.

Events

Anselme scripts communicate with the game by sending events. See the language documentation for more details on events.

Custom events can be defined; to do so, simply yield the coroutine with your custom event type (using coroutine.yield("event type", event_data)) from a function called in the anselme script.

For example, to add a wait event that pauses the script for some time, you could do something along these lines:

state:define("wait", "(duration::is number)", function(duration) coroutine.yield("wait", duration) end)
waiting = false

-- and edit your Anselme event handler with something like:
if not waiting then
	local event_type, event_data = run_state = run_state:step()
	if e == "wait" then
		waiting = true
		call_after_duration(event_data, function() waiting = false end)
	else
	-- handle other event types...
	end
end

And then from your Anselme script:

| Hello...
---
wait(5)
| ...world !

TextEventData

TextEventData represent the data returned by an event with the type "text". See the language documentation for more details on how to create a text event.

A TextEventData contains a list of LuaText, each LuaText representing a separate line of the text event.

For example, the following Anselme script:

| Hi!
| My name's John.

will return a text event containing two LuaTexts, the first containing the text "Hi!" and the second "My name's John.".

Usage:

local event_type, event_data = run_state:step()
if event_type == "text" then
	-- event_data is a TextEventData, i.e. a list of LuaText
	for _, luatext in ipairs(event_data) do
 		-- luatext is a list of text parts { text = "text string", tags = { ... } }
		for _, textpart in ipairs(luatext) do
			write_text_part_with_color(textpart.text, textpart.tags.color)
		end
		write_text("\n") -- for example, if we want a newline between each text line
	end
else
-- handle other event types...
end

defined at line 87 of anselme/ast/Text.lua: local TextEventData

:group_by (tag_key)

Returns a list of TextEventData where the first part of each LuaText of each TextEventData has the same value for the tag tag_key.

In other words, this groups all the LuaTexts contained in this TextEventData using the tag_key tag and returns a list containing these groups.

For example, with the following Anselme script:

speaker: "John" #
	| A
	| B
speaker: "Lana" #
	| C
speaker: "John" #
	| D

calling text_event_data:group_by("speaker") will return a list of three TextEventData:

the first with the texts "A" and "B"; both with the tag speaker="John"
the second with the text "C"; with the tag speaker="Lana"
the last with the text "D"; wiith the tag speaker="John"

defined at line 109 of anselme/ast/Text.lua: group_by = function(self, tag_key)

ChoiceEventData

ChoiceEventData represent the data returned by an event with the type "choice". See the language documentation for more details on how to create a choice event.

A ChoiceEventData contains a list of LuaText, each LuaText representing a separate choice of the choice event.

For example, the following Anselme script:

*| Yes!
*| No.

will return a choice event containing two LuaTexts, the first containing the text "Yes!" and the second "No.".

Usage:

current_choice = nil
waiting_for_choice = false

-- in your anselem event handling loop:
if not waiting_for_choice then
	local event_type, event_data = run_state:step()
	if event_type == "choice" then
		-- event_data is a ChoiceEventData, i.e. a list of LuaText
		for i, luatext in ipairs(event_data) do
			write(("Choice number %s:"):format(i))
 			-- luatext is a list of text parts { text = "text string", tags = { ... } }
			for _, textpart in ipairs(luatext) do
				write_choice_part_with_color(textpart.text, textpart.tags.color)
			end
		else
		-- handle other event types...
		end
		current_choice = event_data
		waiting_for_choice = true
	end
end

-- somewhere in your code where choices are selected
current_choice:select(choice_number)
waiting_for_choice = false

defined at line 50 of anselme/ast/Choice.lua: local ChoiceEventData = class {

:choose (choice)

Choose the choice at position choice (number).

A choice must be selected after receiving a choice event and before calling :step again.

defined at line 58 of anselme/ast/Choice.lua: choose = function(self, choice)

LuaText

A Lua-friendly representation of an Anselme Text value. They appear in both TextEventData and ChoiceEventData to represent the text that has to be shown.

It contains a list of text parts, which are parts of a single text, each part potentially having differrent tags attached. A text will typically only consist of a single part unless it was built using text interpolation.

Each text part is a table containing text (string) and tags (table) properties, for example: { text = "text part string", tags = { color = "red" } }.

defined at line 19 of anselme/ast/Text.lua: local LuaText

.raw

Anselme Text value this was created from. For advanced usage only. See the source file Text.lua for more information.

defined at line 27 of anselme/ast/Text.lua: raw = nil,

:__tostring ()

Returns a text representation of the LuaText, using Anselme's default formatting. Useful for debugging.

Usage: print(luatext)

defined at line 41 of anselme/ast/Text.lua: __tostring = function(self)

file generated at 2024-11-17T15:00:50Z

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File metadata and controls

anselme

.version

.versions

.language

.save

.api

.parse (code, source)

.parse_file (path)

.generate_translation_template (code, source)

.generate_translation_template_file (path)

.new ()

State

:load_stdlib (language)

Branching and merging

.branch_id

.source_branch

:branch (branch_id)

:merge ()

Variable definition

:define (name, value, func, raw_mode)

:define_local (name, value, func, raw_mode)

:defined (name)

:defined_local (name)

Saving and loading persistent variables

:save ()

:load (save)

Current script state

:active ()

:state ()

:run (code, source, tags)

:run_file (path, tags)

:step ()

:interrupt (code, source, tags)

:eval (code, source, tags)

:eval_local (code, source, tags)

Events

TextEventData

:group_by (tag_key)

ChoiceEventData

:choose (choice)

LuaText

.raw

:__tostring ()