It's expressions time.

docs/.vitepress/en.ts

@@ -12,7 +12,7 @@ export const en = defineConfig({
                     { text: 'Welcome!', link: '/' },
                     { text: 'Events', link: '/Events' },
                     { text: 'Commands', link: '/Commands' },
-                    { text: 'Arithmetica', link: '/Arithmetica' },
+                    { text: 'Expressions', link: '/Expressions' },
                 ]
             },
             {

docs/Commands.md

@@ -40,19 +40,20 @@ This command type expects a selector and either a list of commands or a function
 
 If you opt into specifying commands using the array, you are a given an option of using command macros.
 
-A macro is a simple `${{}}` block, which allows you to dynamically insert info using extractions. There are two types of macros: string and arithmetic.
-
-A string macro is self-explanatory, it will insert a string into the command, for example:
+A macro is a simple `${{}}` block, which allows you to dynamically insert info using expressions. For example:
 ```
-"/say hi, my name is ${{origin[world/key]}}!"
+"/say hi, my name is ${{level.dimension.location}}!"
 ```
 will say `hi, my name is minecraft:overworld` in the overworld.
 
-An arithmetic macro is a lot more interesting. Arithmetic macros are supported by [Arithmetica](Arithmetica). You can learn more about mathematical expressions on that page.
+You can learn more about expressions on this page: [Expressions](Expressions).
+
+By default macros return a string, but you can cast (convert) a macro into some other types like so:
 
-Arithmetic macros always return a floating point number (`1.7480`), but you can truncate the floating point by adding `(long)` to your expression like so:
 ```
-$(long){{random(0, 34)}}
+$(long){{random(0, 34)}} 34.52946 -> 34
+$(double){{true}} true -> 1.0
+$(bool){{0}} 0 -> false
 ```
 
 ### `commander:cancel`
@@ -116,7 +117,7 @@ Note: even if the condition is true early, the command will still execute all co
 :::
 
 ### `commander:random`
-This command type takes a weighted list of other commands and randomly executes some of them. By default, it rolls only once, but the number of rolls can be adjusted using the optional `rolls` field (Supports [Arithmetica](Arithmetica)).
+This command type takes a weighted list of other commands and randomly executes some of them. By default, it rolls only once, but the number of rolls can be adjusted using the optional `rolls` field (Supports [Expressions](Expressions)).
 
 ::: details Example
 ```json

docs/Events.md

@@ -65,6 +65,4 @@ The subscription file can contain multiple subscriptions to different (or identi
 
 Commander wraps most compatible fabric events under the `commander` namespace. "Return" here means the [cancel command](Commands#commandercancel)
 
-Currently available events can be seen here: [EntityEvents](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/EntityEvents.java), [PlayerEvents](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/PlayerEvents.java), [ServerLifecycle](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/ServerLifecycle.java), [ServerTick](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/ServerTick.java)
-
-TODO: Automatically generate event list.
+Currently available events can be seen here: [EntityEvents](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/EntityEvents.java), [PlayerEvents](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/PlayerEvents.java), [ServerLifecycle](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/ServerLifecycle.java), [ServerTick](https://github.com/constellation-mc/commander/blob/main/src/main/java/me/melontini/commander/impl/builtin/events/ServerTick.java)

docs/Expressions.md

@@ -0,0 +1,67 @@
+# Expressions
+
+Commander introduces support for evaluating math expressions with dynamic context data.
+
+Expressions use [EvalEx](https://ezylang.github.io/EvalEx/) for evaluation, it may be useful to familiarize yourself with it.
+
+## Additional functions
+
+Commander adds some additional functions to EvalEx.
+
+- `random` generates a random number in range. Accepts 2 arguments (min, max)
+- `clamp` clamps the value between two other arguments. Accepts 3 arguments (value, min, max)
+- `lerp` smoothly progresses the value to the target. `start + delta * (end - start)`. Accepts 3 arguments (delta, start, end)
+
+## Context data access
+
+Because Expressions require minecraft's loot context, you can read source data using a special syntax.
+```
+identifier.field
+identifier.method
+identifier.method.field.method
+```
+Keep in mind that requested fields and context **must** be present. Expression will fail without them.
+
+Some examples:
+```
+minecraft:this_entity.getX
+this_entity.getHealth
+minecraft:this_entity.isInWaterOrRain
+this_entity.blockPosition.getX
+origin.x
+origin.reverse.y
+minecraft:level.getDayTime
+```
+
+Expressions use Mojang Mappings (downloaded on first load), this means that almost all public fields and getter methods are available in expressions. If Commander fails to setup mappings, you'll have to rely on platform names. (e.g. intermediary on Fabric)
+
+## Using Expressions
+
+The fastest way to get started is to use the `cmd:arithmetica` command. You should wrap your expression with `"` to satisfy Brigadier.
+
+Other places are [command macros](Commands#command-macros), the `commander:arithmetica` number provider and the `commander:expression` predicate.
+
+Using the predicate:
+
+```json
+{
+  "condition": "commander:expression",
+  "value": "level.isDay"
+}
+```
+
+Using the provider in conditions:
+
+```json
+{
+  "condition": "minecraft:value_check",
+  "value": {
+    "type": "commander:arithmetica",
+    "value": "round(random(5, 15))"
+  },
+  "range": {
+    "min": 12.3,
+    "max": 32
+  }
+}
+```

docs/index.md

@@ -5,7 +5,7 @@ comment: false
 
 Commander is an extension of the vanilla data pack system.
 
-It adds a new event system, flexible json commands, new `/` commands, support for advanced mathematical expressions and more!
+It adds a new event system, flexible json commands, new `/` commands, support for advanced expressions with data access and more!
 
 There are no client-side features available, everything is executed on the server.