SYLESS Language

SYLESS is an English-like programming language — write code the way you speak, no complex syntax required.

Try it live → syless-frontend.vercel.app
Practice SYLESS directly in your browser with the online IDE, no setup needed.

Developed by

NANDACUMAAR — "just make it" startup

Features

Syntax highlighting for all SYLESS keywords, strings, numbers, operators, and interpolated variables
Code snippets — type a keyword and press Tab to expand a full template
Auto-closing brackets — {, [, (, ", '
Auto-indent — code indents automatically inside blocks
.sy file icon — SYLESS files get their own icon in the file explorer
Run with F5 — execute any .sy file directly from the editor

Getting Started

Create a file ending in .sy and start writing:

# Hello World
show "Hello, World!"

# String interpolation
make name = "SYLESS"
show "Welcome to {name}!"

# Variables + compound assignment
make score = 0
score += 50
score += 25
show "Score: {score}"

# Input
ask username -> "Enter your name: "

# Else-if chain with also check
check score >= 90 {
    show "Grade: A"
} also check score >= 70 {
    show "Grade: B"
} otherwise {
    show "Grade: C"
}

# Range loop with counter
loop i from 1 to 5 {
    show "Step: {i}"
}

# Function with default parameter
task greet(name, msg = "Hello") {
    show "{msg}, {name}!"
}

greet("World")
greet("SYLESS", "Welcome to")

Language Reference

Output

Syntax	Description
`say -> "text"`	Print — classic style
`say "text"`	Print — arrow is optional
`show "text"`	Print — friendliest, no arrow needed
`show "Hi {name}!"`	String interpolation — embed variables directly

Variables & Input

Syntax	Description
`make x = 10`	Declare a variable
`ask x -> "prompt"`	Get user input (auto-converts to number if possible)
`x += 5`	Add and assign
`x -= 5`	Subtract and assign
`x *= 2`	Multiply and assign
`x /= 2`	Divide and assign
`nothing`	Represents no value (alias for `null`)

Conditions

Syntax	Description
`check x > 5 { }`	If statement
`check x > 5 { } otherwise { }`	If-else
`} also check x > 3 { }`	Else-if — chain as many as needed

Loops

Syntax	Description
`loop 3 times { }`	Repeat exactly N times
`repeat 3 times { }`	Same as loop — alternate phrasing
`loop i from 1 to 10 { }`	Range loop — `i` goes from 1 to 10 inclusive
`repeat while x < 10 { }`	While loop
`for each item in list { }`	For-each loop over an array

Functions

Syntax	Description
`task name(param) { }`	Define a function
`task name(a, b = 0) { }`	Function with a default parameter value
`give value`	Return a value (like `return` in other languages)

Built-in Functions

Syntax	Result	Description
`length of x`	number	Length of string or array
`upper of x`	string	Convert to UPPERCASE
`lower of x`	string	Convert to lowercase
`round of x`	number	Round to nearest integer
`absolute of x`	number	Absolute value (removes negative sign)

Data Structures

Syntax	Description
`make myStack`	Create a stack (name must contain "stack")
`push value into myStack`	Push to stack
`pop from myStack`	Pop from stack
`make myQueue`	Create a queue (name must contain "queue")
`insert value into myQueue`	Enqueue
`remove from myQueue`	Dequeue
`make linkedList`	Create a linked list (name must contain "linked")
`add value into linkedList`	Append to linked list
`make myTree`	Create a BST (name must contain "tree")
`insert value into myTree`	Insert into BST
`sort myArray ascending`	Sort array smallest to largest
`sort myArray descending`	Sort array largest to smallest
`binary search value in myArray`	Find index in sorted array
`connect nodeA to nodeB`	Add a bidirectional graph edge

Machine Learning

Syntax	Description
`load "iris" as data`	Load a built-in dataset
`train "knn" on data.data with data.target as model`	Train a model
`predict model -> [5.1, 3.5, 1.4, 0.2]`	Make a prediction
`evaluate model on data.data with data.target`	Evaluate model accuracy

Supported models: knn, tree, forest, linear, logistic, bayes, svm
Supported datasets: iris, digits, wine, cancer

Operators

Symbol	Meaning
`->`	Arrow (used with `say`, `ask`, `predict`)
`+` `-` `` `/` `%` `*`	Arithmetic
`+=` `-=` `*=` `/=`	Compound assignment
`==` `!=` `<` `>` `<=` `>=`	Comparison
`and` `or` `not`	Logical

Comments

# This is a comment
show "Hello"  # inline comment

Snippets

Type any of these prefixes and press Tab:

Prefix	Expands to
`say`	`say ->`
`show`	`show`
`make`	`make name =`
`ask`	`ask name -> "prompt"`
`check`	If block
`checkelse`	If-else block
`checkalso`	If / else-if / else chain
`loop`	Loop N times
`loopfrom`	Range loop `loop i from 1 to 10`
`repeat`	Repeat N times
`repeatwhile`	While loop
`foreach`	For-each loop
`task`	Function definition
`taskdefault`	Function with default parameter
`length`	`length of`
`upper`	`upper of`
`lower`	`lower of`
`train`	ML train statement
`predict`	ML predict statement

Online IDE

Practice SYLESS in your browser — no installation needed:

https://syless-frontend.vercel.app/

SYLESS — Code Like You Think
Developed by NANDACUMAAR · "just make it" startup