Add mathjs singleton and expose it via API

This allows for modification of `mathjs` by the user,
mostly to allow for the use of `math.import` to define custom functions

Author: Cube707

exampleVault/Advanced Examples/Customising mathjs.md

@@ -0,0 +1,27 @@
+---
+num: 6
+---
+
+```js-engine
+const mb = engine.getPlugin('obsidian-meta-bind-plugin').api;
+const math = mb.getMathjs();
+
+math.import({
+	clamp: function (val, min, max) { 
+		return Math.min(Math.max(min, val), max);
+	}
+}, {silent:true});
+```
+
+This is a clamped value: `VIEW[clamp({num}, 0, 10)][math]`
+Test it with the slider
+
+```meta-bind
+INPUT[slider(minValue(-5),maxValue(15)):num]
+```
+
+
+> [!Note]
+> Please note the second parameter for `math.import`. 
+> Passing `silent:true` leads to the function <u>not</u> beeing updated on edit! (only on reload of meta-bind)
+> Pass `override:true` to override the function everytime you switch between edit and viewing mode.

packages/core/src/api/API.ts

@@ -1,3 +1,4 @@
+import type { MathJsInstance } from 'mathjs';
 import { SyntaxHighlightingAPI } from 'packages/core/src/api/SyntaxHighlightingAPI';
 import type {
 	ButtonGroupOptions,
@@ -63,6 +64,7 @@ import { Signal } from 'packages/core/src/utils/Signal';
 import { expectType, getUUID } from 'packages/core/src/utils/Utils';
 import { validateAPIArgs } from 'packages/core/src/utils/ZodUtils';
 import { z } from 'zod';
+import { getMathjsSingleton } from 'packages/core/src/utils/Mathjs';
 
 export interface LifecycleHook {
 	register(cb: () => void): void;
@@ -827,4 +829,12 @@ export abstract class API<Plugin extends IPlugin> {
 			lineEnd: lineEnd,
 		});
 	}
+
+	/**
+	 * get the mathjs instance used in math-views. Useful to modify the config and scope.
+	 *
+	 */
+	public getMathjs(): MathJsInstance {
+		return getMathjsSingleton();
+	}
 }

packages/core/src/fields/viewFields/fields/MathVF.ts

@@ -1,10 +1,10 @@
-import type { EvalFunction } from 'mathjs';
-import { compile as MathJsCompile } from 'mathjs';
+import type { EvalFunction, MathJsInstance } from 'mathjs';
 import { AbstractViewField } from 'packages/core/src/fields/viewFields/AbstractViewField';
 import type { ViewFieldMountable } from 'packages/core/src/fields/viewFields/ViewFieldMountable';
 import type { ViewFieldVariable } from 'packages/core/src/fields/viewFields/ViewFieldVariable';
 import { ErrorLevel, MetaBindExpressionError } from 'packages/core/src/utils/errors/MetaBindErrors';
 import { parseLiteral, stringifyUnknown } from 'packages/core/src/utils/Literal';
+import { getMathjsSingleton } from 'packages/core/src/utils/Mathjs';
 import { Signal } from 'packages/core/src/utils/Signal';
 import { DomHelpers, getUUID } from 'packages/core/src/utils/Utils';
 
@@ -13,12 +13,15 @@ export class MathVF extends AbstractViewField<unknown> {
 	expression?: EvalFunction;
 	expressionStr?: string;
 	hasError: boolean;
+	math: MathJsInstance;
 
 	hidden: boolean;
 
 	constructor(mountable: ViewFieldMountable) {
 		super(mountable);
 
+		this.math = getMathjsSingleton();
+
 		this.hidden = false;
 
 		this.hasError = false;
@@ -48,7 +51,7 @@ export class MathVF extends AbstractViewField<unknown> {
 			}
 		}
 
-		this.expression = MathJsCompile(this.expressionStr);
+		this.expression = this.math.compile(this.expressionStr);
 	}
 
 	private buildMathJSContext(): Record<string, unknown> {

packages/core/src/utils/MathJS.ts

@@ -0,0 +1,8 @@
+import type { MathJsInstance } from 'mathjs';
+import { create as MathjsCreate, all } from 'mathjs';
+
+const math = MathjsCreate(all);
+
+export function getMathjsSingleton(): MathJsInstance {
+	return math;
+}