schemioscript

name	schemioscript
description	Create and analyze SchemioScript code
license	Mozilla Public License Version 2.0
metadata	{"author":"Ivan Shubin","version":"1.0.0"}

SchemioScript Language Skill

Overview

SchemioScript is a JavaScript-like scripting language designed for Schemio diagrams. It enables dynamic behavior, item manipulation, and complex interactions within diagram items.

Key Characteristics:

• JavaScript-like syntax with simplifications
• Dynamically typed
• Expression-oriented (last statement is return value)
• No explicit variable declaration keywords (except let for local scoping)
• Designed for diagram item scripting and templating

---

Basic Syntax

Variable Declaration

No const, let, or var keywords required. Simply assign a value:

name = "John"
age = 19
x = 4 + 5 * 4 + y

Multiple Statements

Separated by semicolon ; or newline:

x = 1; y = 2; z = x + y

// Or over multiple lines
a = 4 +
5 * 4 + y
% 3

Expression Return Value

Only the last statement in an expression is considered the return value:

// This returns 30
x = (a = 1; b = 2; a + b); x*10

---

Data Types

Primitives

• Number: 42, 3.14, -10
• String: 'hello', "world"
• Boolean: true, false
• Null: null

Complex Types

• Vector: 2D vector with x and y properties
• List: Ordered collection (similar to arrays)
• Map: Key-value pairs (hash table)
• Set: Collection of unique values
• Struct: Custom complex objects

---

Operators

Arithmetic

Operator	Name	Example
+	Addition	a + b
-	Subtraction	a - b
*	Multiplication	a * b
/	Division	a / b
%	Modulo	a % b
^	Power	a ^ b (a to the power of b)

Comparison

Operator	Name	Example
==	Equal	x == y
!=	Not equal	x != y
>	Greater than	x > y
<	Less than	x < y
>=	Greater than or equal	x >= y
<=	Less than or equal	x <= y

Logical

Operator	Name	Example
&&	AND	x > 0 && y < 10
`		`
!	NOT	!(x > 0)

Bitwise

Operator	Name	Example
&	AND	a & b
`	`	OR
~	NOT	~a
<<	Left shift	a << b
>>	Right shift	a >> b

Assignment

Operator	Name	Example
=	Assign	x = 5
+=	Add and assign	x += 5
-=	Subtract and assign	x -= 5
*=	Multiply and assign	x *= 5
/=	Divide and assign	x /= 5

Increment/Decrement

Operator	Name	Example
++	Increment	x++ or ++x
--	Decrement	x-- or --x

Note: Pre-increment (++x) and post-increment (x++) are supported.

---

Control Structures

If Statements

If statements can be used as expressions and return the last executed statement:

x = 5
y = 3
result = 1

if (z == 0) {
    result = x + y
} else if (z == 1) {
    result = x * y
} else {
    result = x - y
}

As an expression:

x = getPosX()
x = if (x < 100) {
    step = 4
    x + step
} else { 0 }

While Loops

i = 0
sum = 0
while (i < 10) {
    sum += i
    i += 1
}

For Loops

C-like for loops:

for (i = 0; i < 5; i++) {
    log(i)
}

Multiple initializations:

for (i = 0, j = 10; i < j; i++, j--) {
    log(i, j)
}

---

Templated Strings

Use backticks to embed expressions in strings:

setTextColor('body', `rgba(${r + 10}, ${g}, 20, 0.5)`)

---

Item Referencing

Reference other diagram items using the @ symbol:

// Reference by name
pos = @Rect.getWorldPos()
@Rect.setWorldPos(pos.x + 20, pos.y - 10)

// Reference with special characters (use quotes)
pos = @"Rect 2".getWorldPos()
@"Rect 2".setWorldPos(pos.x + 20, pos.y - 10)

// Dynamic item referencing with templated strings
for (i = 1; i < 10; i++) {
    pos = @`Rect ${i}`.getWorldPos()
    @`Rect ${i}`.setWorldPos(pos.x + 20, pos.y - 10)
}

---

Vector Type

2D vector for geometric calculations:

Creating Vectors

v1 = Vector(3, 4)
v2 = Vector(1, -2)

Vector Properties

• x: X coordinate
• y: Y coordinate

Vector Operations

dx = v1.x - v2.x
dv = v1 - v2         // Vector subtraction
v3 = v1 + v2         // Vector addition
v4 = v1 * 10        // Scalar multiplication
v5 = v1 / 2         // Scalar division
v6 = 5 * v1         // Scalar on left side

Vector Functions

Function	Description	Returns
length()	Returns the magnitude/length of the vector	Number
normalized()	Returns a unit vector in the same direction	Vector
projection(v)	Returns scalar projection of this vector onto vector v	Number
rotate(angle)	Returns vector rotated by angle radians	Vector
inverse()	Returns the negated vector	Vector

Examples

v = Vector(3, 5)
d = v.length()
normal = v.normalized()

v1 = Vector(1, 3)
v2 = Vector(4, 1)
p = v1.projection(v2)  // Scalar projection

v = Vector(2, 7)
v2 = v.rotate(PI() / 2)  // Rotate by 90 degrees

v = Vector(2, 7)
v_inv = v.inverse()  // Returns Vector(-2, -7)

---

List Type

Ordered collection similar to arrays:

Creating Lists

items = List(4, 5, 2)
emptyList = List()

List Functions

Function	Description	Returns
add(item)	Adds item to end of list	List (chained)
remove(index)	Removes item at index	List (chained)
get(index)	Gets item at index	Any
set(index, value)	Sets item at index	List (chained)
insert(index, value)	Inserts value at index	List (chained)
size	Number of items	Number
findIndex(callback)	Finds index of first matching element	Number (-1 if not found)
forEach(callback)	Iterates all items	void
map(callback)	Maps items to new values	List
filter(predicate)	Filters items	List
pop()	Removes and returns last item	Any
shift()	Removes and returns first item	Any
first()	Returns first item	Any
last()	Returns last item	Any
extendList(otherList)	Appends all items from another list	void

Examples

items = List('a', 'b', 'c')
items.add('d')
items.remove(1)  // Removes 'b'
item1 = items.get(0)  // 'a'

// Iteration
items.forEach((item, index) => {
    log(index, item)
})

// Mapping
numbers = List(1, 2, 3)
doubled = numbers.map((value, index) => { value * 2 })

// Filtering
filtered = numbers.filter((value) => { value > 1 })

// Find index
idx = items.findIndex((item) => { item == 'b' })

---

Map Type

Hash table for key-value pairs:

Creating Maps

m = Map('name', 'John', 'age', 30)
emptyMap = Map()

Map Functions

Function	Description	Returns
get(key)	Gets value for key	Any
set(key, value)	Sets value for key	void
has(key)	Checks if key exists	Boolean
delete(key)	Removes key-value pair	void
forEach(callback)	Iterates all entries	void

Examples

m = Map('name', 'John', 'age', 30)
log('Name:', m.get('name'))
m.set('age', 31)
m.has('name')  // true
m.delete('age')

m.forEach((value, key) => {
    log(key, value)
})

---

Set Type

Collection of unique values:

Creating Sets

s = Set('a', 'b', 'c', 'a')  // Duplicate 'a' is ignored
emptySet = Set()

Set Functions

Function	Description	Returns
add(value)	Adds value to set	void
delete(value)	Removes value from set	void
has(value)	Checks if value exists	Boolean
forEach(callback)	Iterates all values	void

Examples

s = Set('a', 'b', 'c')
s.add('d')
s.has('a')  // true
s.delete('b')

s.forEach((value) => {
    log(value)
})

---

Function Declaration

Named Functions (func keyword)

func minValues(a, b) {
    if (a < b) {
        a
    } else {
        b
    }
}
log(minValues(4, 1))  // 1

Arrow Functions

myFunc = () => {
    log('This is my function')
}

myMin = (a, b) => {
    if (a < b) {
        a
    } else {
        b
    }
}
log(myMin(4, 1))  // 1

Functions as Return Values

myMin = (a) => {
    (b) => {
        if (a < b) {a} else {b}
    }
}
log(myMin(4)(3))  // 3

Function Invocation

result = myFunc(arg1, arg2)

---

Local Variables

Use let keyword to create variables with function/loop/if scope:

name = 'John'

func someFunc() {
    let name  // Declares local variable
    name = 'Sara'
    log(name)  // 'Sara'
}

someFunc()
log(name)  // 'John' - outer variable unchanged

Shorthand declaration and assignment:

func someFunc() {
    let name = 'Sara'
    // ...
}

---

Structs

Custom complex object types:

Defining Structs

struct TreeNode {
    id: ''
    value: null
    parent: null
    childNodes: List()

    addNode(node) {
        this.childNodes.add(node)
        node.parent = this
    }
}

Simple field declarations (no defaults):

struct Point {x, y}

Creating Struct Instances

root = TreeNode('root')
child1 = TreeNode('child 1', 'custom value')
root.addNode(child1)

p1 = Point(0, 1)
p2 = Point(-3, 2)

Struct Features

• Fields are initialized with default values if not provided
• Methods can access struct instance via this keyword
• Constructor accepts arguments in order of field declarations

---

Built-in Functions

Math Functions

Function	Description	Returns
abs(x)	Absolute value	Number
min(a, b, ...)	Minimum value	Number
max(a, b, ...)	Maximum value	Number
pow(x, y)	x raised to power y	Number
sqrt(x)	Square root	Number
cos(x)	Cosine (radians)	Number
sin(x)	Sine (radians)	Number
tan(x)	Tangent (radians)	Number
acos(x)	Arc cosine	Number
asin(x)	Arc sine	Number
atan(x)	Arc tangent	Number
logn(x)	Natural logarithm (base e)	Number
log10(x)	Base 10 logarithm	Number
log2(x)	Base 2 logarithm	Number
log(x, ...)	Console log (debugging)	void
round(x)	Round to nearest integer	Number
ceil(x)	Round up	Number
floor(x)	Round down	Number
PI()	PI constant	Number
rnd()	Random float [0, 1)	Number

Examples

y = abs(-5)  // 5
x = pow(3, 2)  // 9
angle = PI() / 4  // 45 degrees in radians
random = rnd() * 10  // Random 0-10
value = round(3.78)  // 4

String & Text Functions

Function	Description	Returns
rgba(r, g, b, a)	RGBA color string	String
parseInt(text)	Parse integer	Number
parseFloat(text)	Parse float	Number
matchesRegex(text, pattern)	Regex match	Boolean
splitString(str, separator)	Split string	List

Color Functions

Function	Description	Returns
Color(r, g, b, a)	Create color object	Color
decodeColor(text)	Decode color from string	Color

Color Object Methods:

• encode(): Encodes color to string
• gradient(anotherColor, t): Mix with another color (t = 0-1)

Examples

color = Color(255, 145, 140, 1.0)
encoded = color.encode()  // "rgba(255,145,140,1)"
color2 = Color(100, 0, 10, 1.0)
color3 = color.gradient(color2, 0.7)

color = decodeColor("rgba(255,240,200,1.0)")
log(color.r, color.g, color.b, color.a)

Utility Functions

Function	Description	Returns
uid()	Unique ID string	String
ifcond(condition, a, b)	Conditional expression	Any
getEventName()	Current event name	String
getEventArg(i)	Event argument at index	Any

Examples

id = uid()
result = ifcond(x > 10, -1, 1)  // -1 if x > 10, else 1

eventName = getEventName()
arg0 = getEventArg(0)

Type Conversion

Function	Description	Returns
toJSON(obj)	Convert to JSON	Object
fromJSON(obj)	Convert from JSON	Any
encodeJSON(obj)	JSON string	String
parseJSON(text)	Parse JSON string	Any

---

Item Functions

Functions available in the context of diagram items. These functions operate on the current item unless specified otherwise.

Identification

Function	Description	Returns
getId()	Item internal ID	String
getName()	Item name	String
getShape()	Shape ID	String
getTags()	Item tags	List

Position & Transformation

Function	Description	Returns
getPosX()	X position (local)	Number
getPosY()	Y position (local)	Number
getPos()	Position as Vector (local)	Vector
getWorldPos()	Position as Vector (world)	Vector
setWorldPos(x, y)	Set world position	void
setPosX(x)	Set X position (local)	void
setPosY(y)	Set Y position (local)	void
setPos(x, y)	Set position (local)	void
setPos(Vector)	Set position using Vector	void
getWidth()	Item width	Number
getHeight()	Item height	Number
getAngle()	Rotation angle (degrees)	Number
setAngle(angle)	Set rotation angle	void
getScaleX()	X scale	Number
getScaleY()	Y scale	Number
setScaleX(x)	Set X scale	void
setScaleY(y)	Set Y scale	void
getOpacity()	Opacity (0-100)	Number
getSelfOpacity()	Self opacity (0-100)	Number
setOpacity(opacity)	Set opacity	void
setSelfOpacity(opacity)	Set self opacity	void

Coordinate Conversion

Function	Description	Returns
worldPoint(x, y)	Local to world coordinates	Vector
localPoint(x, y)	World to local coordinates	Vector
matchWorld(x, y, worldX, worldY)	Match local point to world point	void

Visibility

Function	Description	Returns
isVisible()	Check visibility	Boolean
show()	Show item	void
hide()	Hide item	void

Mounting

Function	Description	Returns
mountTo(otherItem)	Mount to another item	void
mountChild(otherItem)	Mount item to self	void
mountRoot()	Mount to root	void

Text Functions

Function	Description	Returns
setText(textSlotName, text)	Set text for slot	void
setTextColor(textSlotName, color)	Set text color	void
setTextSize(textSlotName, size)	Set text font size	void

Custom Variables

Function	Description	Returns
setVar(name, value)	Store custom variable	void
getVar(name, defaultValue)	Get custom variable	Any

Examples

// Store and retrieve custom variables
setVar('srcX', getPosX())
setVar('dstX', -467*(slide - 1))

// Use in another function
setPosX(getVar('srcX') * (1 - t) + getVar('dstX') * t)

// Get with default
srcX = getVar('srcX', 0)
dstX = getVar('dstX')  // No default

Events

Function	Description	Returns
sendEvent(eventName, ...args)	Send custom event	void

Finding Items

Function	Description	Returns
findItemByName(name)	Find item by name	Item
findItemById(id)	Find item by ID	Item
findChildItemByName(name)	Find child item by name	Item
findChildItemsByTag(tag)	Find child items by tag	List
findParent()	Find parent item	Item

Item Manipulation

Function	Description	Returns
duplicate(name)	Create copy of item	Item
remove()	Remove item from scene	void
removeChildItemsByTag(tagName)	Remove child items by tag	void
tag(tagName)	Add tag to item	void

Examples

// Find and manipulate other items
it = findItemByName('ellipse')
dstX = it.getVar('dstX')
it.setPosX(dstX)
it.setTextSize('body', 30)

// Send custom events
sendEvent('my-custom-move', 'up', 10)

// Handle custom events
d = ifcond(getEventArg(0) == 'up', -1, ifcond(getEventArg(0) == 'down', 1, 0))
speed = getEventArg(1)
setPosY(getPosY() + speed * d)

// Duplicate items
newItem = duplicate('new_name')
newItem.setWorldPos(100, 0)

// Remove items
item = @Rect
item.remove()

// Add tags
rectItem = @Rect
rectItem.tag('new-tag')

---

Connector Functions

Additional functions for connector items:

Function	Description	Returns
totalPoints()	Number of points	Number
getPointWorldPos(index)	Position of point	Vector
setPointWorldPos(idx, x, y)	Set point position	void
addWorldPoint(x, y)	Add new point	Number (index)
removePoint(pointIdx)	Remove point	void
getLength()	Total path length	Number
getWorldPosAtLength(length)	Position at length	Vector

Examples

connector = findItemByName('Connector 1')
n = connector.totalPoints()
p = connector.getPointWorldPos(1)
connector.setPointWorldPos(1, 45, -4)
pointIdx = connector.addWorldPoint(6, 1)
connector.removePoint(2)
length = connector.getLength()
p = connector.getWorldPosAtLength(56)

---

Path Functions

Functions for path items (similar to connectors but with multiple sub-paths):

Function	Description	Returns
totalPaths()	Number of paths	Number
totalPathPoints(pathIndex)	Number of points in path	Number
isPathClosed(pathIdx)	Check if path is closed	Boolean
closePath(pathIdx)	Close path	void
openPath(pathIdx)	Open path	void
getPathPointWorldPos(pathIdx, pointIdx)	Point position	Vector
setPathPointWorldPos(pathIdx, pointIdx, x, y)	Set point position	void
addPath()	Add new path	Number (index)
addPoint(pathIdx, x, y)	Add point to path	void
addBezierPoint(pathIdx, x, y, x1, y1, x2, y2)	Add Bezier point	void
getPathLength(pathIdx)	Length of path	Number
getPathWorldPosAtLength(pathIdx, length)	Position at length	Vector

Examples

pathItem = findItemByName('Path 1')
n = pathItem.totalPaths()
pointsNum = pathItem.totalPathPoints(0)
pathItem.closePath(0)
p = pathItem.getPathPointWorldPos(0, 4)
pathItem.setPathPointWorldPos(0, 4, 100, -54)
pathIdx = pathItem.addPath()
pathItem.addPoint(0, 5, 8)
pathItem.addBezierPoint(0, 5, 8, 2, 3, -1, -3)

---

Table Functions

Functions for table items:

Function	Description	Returns
setCellText(row, column, text)	Set cell text	void
getCellText(row, column)	Get cell text	String

---

Math Block Functions

Functions for math block items:

Function	Description	Returns
setExpression(expression)	Set TeX expression	void

Note: Escape backslashes in TeX expressions:

mathBlock = findItemByName('Math 1')
mathBlock.setExpression('c = \\pm\\sqrt{a^{23} + b^{-12}}')

---

Value Functions

Functions available for modifying the "value" of the item, typically used by "textfield" shapes but could be used on any item.

Function	Description	Returns
getValue()	Get value	String
setValue(value)	Set value	void

---

Reserved Keywords

Keyword	Purpose
if	Conditional statement
else	Else clause
while	While loop
for	For loop
true	Boolean true
false	Boolean false
null	Null value
struct	Struct definition
func	Function declaration
local	Local variable (alias for let)
let	Local variable
return	Return from function
enc	Encode expression

---

Operator Precedence

From highest to lowest:

1. ^ (power)
2. /, *, %
3. -, + (binary)
4. <<, >>
5. &
6. |
7. <, >, <=, >=
8. !=, ==
9. &&
10. ||
11. ++, --
12. -=, +=, *=
13. =

---

Implementation Details

Entry Point

• File: src/ui/templater/ast.js
• Function: parseExpression(expression)
• Returns: ASTNode

Tokenization

• File: src/ui/templater/tokenizer.js
• Function: tokenizeExpression(text)
• Token types: TERM, NUMBER, STRING, STRING_TEMPLATE, OPERATOR, RESERVED, etc.

AST Node Types

• ASTNode: Base class for all AST nodes
• ASTValue: Literal values (numbers, booleans, null)
• ASTVarRef: Variable reference
• ASTAssign: Assignment operation
• ASTMultiExpression: Multiple expressions (last is return value)
• ASTIFStatement: If statement
• ASTWhileStatement: While loop
• ASTForLoop: For loop
• ASTFunctionDeclaration: Function definition
• ASTFunctionInvocation: Function call
• ASTExternalObjectLookup: Item reference (@)
• ASTStringTemplate: Templated string
• ASTStructNode: Struct definition
• ASTLocalVariable: Local variable declaration

Execution Context

• Scope: Manages variable bindings and scope chains
• File: src/ui/templater/scope.js
• Supports nested scopes with parent references
• Provides external object lookup for @ references

Built-in Types Implementation

• Vector: src/ui/templater/vector.js
• List: src/ui/templater/list.js
• Color: src/ui/templater/color.js
• Map/Set: JavaScript built-ins wrapped in reservedFunctions

---

Common Patterns

Animation

// Linear interpolation
t = getEventArg(0)  // Assume t is 0-1
srcX = getVar('srcX', getPosX())
dstX = getVar('dstX', 100)
setPosX(srcX * (1 - t) + dstX * t)

Conditional Formatting

if (getValue() > 100) {
    setTextColor('body', 'rgba(255,0,0,1)')
} else {
    setTextColor('body', 'rgba(0,255,0,1)')
}

Looping Through Items

for (i = 1; i <= 10; i++) {
    item = findChildItemByName(`item-${i}`)
    if (item) {
        item.setPosX(i * 50)
    }
}

Using Vectors

pos = getWorldPos()
targetPos = @Target.getWorldPos()
direction = (targetPos - pos).normalized()
distance = pos.distance(targetPos)  // Note: Not built-in, would need custom implementation

Struct with Methods

struct Circle {
    x: 0
    y: 0
    radius: 10

    area() {
        PI() * this.radius * this.radius
    }

    circumference() {
        2 * PI() * this.radius
    }
}

c = Circle(5, 5, 20)
log(c.area())

---

Limitations

1. No native arrays (use List instead)
2. No classes (use structs for similar functionality)
3. No this keyword outside of struct methods
4. No new operator (constructors are just functions)
5. Limited error messages in some cases
6. No switch statements (use if-else chains)
7. No break or continue in loops
8. No try-catch error handling
9. No delete operator for object properties
10. No computed property names

---

Debugging

Logging

log('Value:', x, 'Another:', y)

Item Debugging

debugItem()  // Prints item information to console

Error Handling

The language has limited error handling. Use conditional checks to avoid errors:

if (item) {
    item.setPosX(100)
}

---

Quick Reference Card

┌───────────────────────────────────────────────────────────────┐
│                  SCHEMIO SCRIPT QUICK REFERENCE               │
├───────────────────────────────────────────────────────────────┤
│ VARIABLES: name = value           LOCAL: let name = value     │
│ IF: if (cond) { ... } else { ... }                            │
│ LOOPS: while (cond) { ... }    for (init; cond; step) { ... } │
│ FUNCTIONS: func f(a,b) { ... }    (a,b) => { ... }            │
│ ITEMS: @ItemName    @"Item 2"    @`Item ${i}`                 │
│ VECTOR: Vector(x,y)  v.length()  v.normalized()               │
│ LIST: List(a,b,c)   list.map()   list.filter()                │
│ MAP: Map(k1,v1,k2,v2)  map.get(k)  map.set(k,v)               │
│ SET: Set(a,b,c)  set.has(a)  set.add(b)                       │
│ STRUCT: struct Name { field: default, method() { ... } }      │
│ MATH: abs()  min()  max()  pow()  sqrt()  PI()  rnd()         │
│ COLOR: Color(r,g,b,a)  decodeColor(s)  color.gradient(c,t)    │
│ ITEM: getPosX()  setPos(x,y)  getWidth()  setText(slot, text) │
│ EVENT: sendEvent(name, args)  getEventName()  getEventArg(i)  │
└───────────────────────────────────────────────────────────────┘