Syntax Basics

Theory

Syntax is the formal grammar that tells PriyoScript how to read and execute your program. If syntax is valid, the interpreter can understand your intent and run statements in deterministic order. PriyoScript is designed to keep this grammar explicit and readable, so beginners can identify program structure quickly while still writing production-quality logic. In practical terms, syntax defines how you enter a program (monalisa { ... }), how you store data, how you branch and loop, how you define reusable functions, and how you organize code through modules and classes.

Why this matters

Good syntax habits reduce debugging time and make every advanced concept easier to learn.

Syntax Catalog

Basic Structure

Syntax	Description
`monalisa { ... }`	Program entry block. All executable statements start here.
`// comment`	Single-line comment.
`/* comment */`	Multi-line comment block.

Literals and Values

Syntax	Description
`123`, `3.14`	Number literals.
`"mona"`	String literal.
`priyoTrue`, `priyoFalse`	Boolean literals.
`priyoEmpty`	Null-like empty value.

Variables and Assignment

Syntax	Description
`priyoKeep x = 1`	Function-scoped mutable declaration.
`priyoChange x = 1`	Block-scoped mutable declaration.
`priyoPromise x = 1`	Block-scoped immutable binding.
`x = x + 1`	Reassignment (not valid for `priyoPromise`).

Expressions and Operators

Syntax	Description
`a + b`, `a - b`, `a * b`, `a / b`	Arithmetic expressions.
`a == b`, `a >= b`, `a != b`	Comparison expressions.
`a && b`, `a \|\| b`, `!a`	Logical expressions.
`(a + b) * c`	Grouping with precedence control.

Control Flow

Syntax	Description
`prakritiIf (...) { ... }`	Conditional branch.
`prakritiElseIf (...) { ... }`	Additional condition branch.
`prakritiElse { ... }`	Fallback branch.
`prakritiCount (...) { ... }`	Counted loop.
`prakritiAsLongAs (...) { ... }`	While loop.
`prakritiStop`, `prakritiGoOn`	Break/continue style flow control.
`prakritiThink("label")`	Debug checkpoint marker for trace.

Functions

Syntax	Description
`lisaaTask name(...) { ... }`	Function declaration.
`prakritiWait lisaaTask ...`	Async function declaration (stage-1).
`priyoGiveBack value`	Return from function.
`name(arg)`	Function call.
`prakritiPause expr`	Await value inside async functions (top-level await supported).

Concurrency Runtime

Syntax	Description
`priyoConcurrency.group("label")`	Create a structured task group.
`group.run(task, arg1, arg2)`	Start a task immediately inside the group.
`group.schedule(25, task, arg1)`	Start a task after a delay in milliseconds.
`prakritiPause group.all()`	Wait for all tasks in the group.
`group.token()`	Get the shared cancellation token.
`token.throwIfCancelled()`	Stop cooperatively if the token was cancelled.
`prakritiPause priyoConcurrency.after`	Delay and resume later with a value or `null`.

Arrays

Syntax	Description
`[1, 2, 3]`	Array literal.
`arr[0]`	Index read.
`arr[1] = 9`	Index write.
`arr[1:3]`	Slice (range extraction).

OOP

Syntax	Description
`lisaaFamily ClassName { ... }`	Class declaration.
`priyoCreate ClassName(...)`	Instance creation.
`priyoSelf`	Current instance reference.
`lisaaInherit Parent`	Inheritance from parent class.
`priyoParent(...)`	Parent constructor call.

Modules and Packages

Syntax	Description
`lisaaBox { ... }`	Module declaration boundary.
`lisaaShare symbol`	Module export.
`lisaaBring "path": alias`	Module import with alias.
`lisaaBring math`	Built-in package import.

Example Programs

Example 1: Basic Output + Variables

monalisa {
  priyoKeep name = "mona"
  priyoPromise version = "stable"
  priyoTell("Hello " + name + " (" + version + ")")
}

Expected output:

Hello mona (stable)

Example 2: Condition + Loop

monalisa {
  prakritiCount (priyoChange i = 1; i <= 3; i = i + 1) {
    prakritiIf (i == 2) {
      priyoTell("middle")
    } prakritiElse {
      priyoTell(i)
    }
  }
}

Expected output:

1
middle
3

Example 3: Function + Array

monalisa {
  lisaaTask sum2(a, b) {
    priyoGiveBack a + b
  }

  priyoKeep nums = [5, 7]
  priyoTell(sum2(nums[0], nums[1]))
}

Expected output:

Common mistake

Do not use priyoGiveBack outside a function body.

Practice Check

Concept Check

Which declaration should you choose for a value that must not be reassigned?
What is the difference between arr[1] and arr[1:3]?
Why must executable code be inside monalisa { ... }?

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