Slvr Smart Contract Language

Language Overview

Slvr is a production-ready smart contract language with:

• Linear type system (resource safety)
• Fuel metering (deterministic execution)
• Parallel execution (multi-core support)
• 60+ built-in functions
• IDE support (LSP, Debugger, Profiler)
• 100% Pact compatible

Basic Syntax

Functions

(defun hello (name)
  "Greet someone"
  (+ "Hello, " name "!")
)

(defun add (a b)
  "Add two numbers"
  (+ a b)
)

Variables

(let ((x 10)
      (y 20))
  (+ x y)
)

Conditionals

(if (> x 10)
  "x is greater than 10"
  "x is less than or equal to 10"
)

Built-in Functions

String Functions

• (+ "hello" " " "world") - Concatenate strings
• (length "hello") - Get string length
• (substring "hello" 0 3) - Extract substring
• (upcase "hello") - Convert to uppercase
• (downcase "HELLO") - Convert to lowercase

Math Functions

• (+ 1 2 3) - Addition
• (- 10 3) - Subtraction
• (* 4 5) - Multiplication
• (/ 20 4) - Division
• (mod 10 3) - Modulo
• (pow 2 8) - Power

List Functions

• (list 1 2 3) - Create list
• (length [1 2 3]) - Get list length
• (first [1 2 3]) - Get first element
• (rest [1 2 3]) - Get rest of list
• (map + [1 2 3]) - Map function over list

Cryptographic Functions

• (blake3 "data") - Blake3 hash
• (sha512 "data") - SHA-512 hash
• (verify-signature sig pubkey msg) - Verify signature

Type System

Basic Types

• int - Integer
• string - String
• bool - Boolean
• list - List
• object - Object/Map

Linear Types

Linear types prevent resource duplication:

(defun transfer (from to amount)
  "Transfer tokens (linear type ensures no duplication)"
  (let ((balance (get-balance from)))
    (if (>= balance amount)
      (do
        (set-balance from (- balance amount))
        (set-balance to (+ (get-balance to) amount))
        true
      )
      false
    )
  )
)

Fuel Metering

All operations have deterministic costs:

• Basic operation: 1 fuel
• String operation: 10 fuel
• Cryptographic operation: 1000 fuel
• Database operation: 100 fuel

Best Practices

• Always validate inputs
• Use linear types for resources
• Keep functions small and focused
• Document with docstrings
• Test thoroughly before deployment
• Monitor fuel usage