9b16b17804
Remove last broad cSpell bypass regex and fix all violations This bypassed all code blocks within markdown files (I didn't notice this one before because it was just for markdowns; it explains some weirdness I was seeing) Now the only remaining restriction is about colors, which I like Also removed all usages of cSpell:disable in favor of word-specific bypasses
3.4 KiB
Functions
A function in YarnSpinner is the same notion as in any other programming language, or in math: it takes a certain number of arguments, and then computes and returns the result. A function call is indicated by the name of the function, followed by its arguments in parentheses. The parentheses are required, even when there are no arguments:
<<set $roll_2d6 = dice(6) + dice(6)>>
<<set $random = random()>>
There are around 20 built-in functions in Jenny, listed below; and it is also possible to add user-defined functions as well.
Built-in functions
-
Random functions
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Numeric functions
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Type conversion functions
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Other functions
User-defined functions
In addition to the built-in functions, you can also define any number of user-defined functions which can later be used in your yarn scripts. The syntax for these functions is exactly the same as for the built-in functions: it consists of a function name, followed by the arguments in parentheses.
Each user-defined function has a fixed signature, declared at the time when the function is added
to the YarnProject. A function must have a fixed number of arguments of specific types, and a
fixed return type.
All user-defined functions must be added to the YarnProject before they can be used. A compile
error will be raised if the parser encounters an unknown function, or if the number or types of
arguments do not match.
User-defined functions can be used for a variety of purposes, such as:
- implement functionality that is currently missing in Jenny;
- interface with the game engine;
- provide access to "variables" stored outside of Jenny;
- etc.
title: Blacksmith
---
// This example showcases several hypothetical user-defined functions:
// - broken(slot): checks whether the item in the given slot is broken;
// - name(slot): gives the name for an item in a slot, e.g. "sword" or "bow";
// - money(): returns the current amount of money that the player has.
// At the same time, functions `round()` and `plural()` are built-in.
<<if broken("main_hand")>>
<<local $repair_cost = round(value("main_hand") / 5)>>
Blacksmith: Your {name("main_hand")} seems to be completely broken!
Blacksmith: I can fix it for just {plural($repair_cost, "% coin")}
-> Ok, do it <<if money() >= $repair_cost>>
-> I'll be fine...
<<endif>>
===
- [`FunctionStorage`](../../../runtime/function_storage.md) -- document
describing how to add user-defined functions to a `YarnProject`.
:hidden:
Random functions <random.md>
Numeric functions <numeric.md>
Type conversion functions <type.md>
Miscellaneous functions <misc.md>