PineTS Syntax Guide

This guide explains how to write PineTS code that is equivalent to Pine Script. PineTS is designed to be written in JavaScript/TypeScript but behaves like Pine Script's runtime execution model.

Variable Declarations

PineTS distinguishes between let and var declarations to mimic Pine Script's behavior. This is a critical difference from standard JavaScript.

let vs var

Feature	Pine Script	PineTS (JS/TS)	Behavior
Re-initialization	float x = close	let x = close	Variable is re-initialized/calculated on every bar.
State Persistence	var float x = 0.0	var x = 0.0	Variable is initialized only once (first bar) and retains its value across bars.

⚠️ Important for JS Developers: In PineTS, var does not behave like standard JavaScript var. It adopts Pine Script's var semantics (persistent state). If you need standard JS function-scoped variables that reset every time, use let.

Example: State Persistence

Pine Script:

// 'sum' retains its value across bars
var float sum = 0.0
sum := sum + close

PineTS:

// 'sum' retains its value across bars
var sum = 0.0;
sum = sum + close;

Loops

PineTS supports standard JavaScript loops, which map to Pine Script's loops.

Feature	Pine Script	PineTS (JS/TS)
For Loop	for i = 0 to 10	for (let i = 0; i <= 10; i++)
While Loop	while i < 10	while (i < 10)

Example: For Loop

Pine Script:

float sum = 0.0
for i = 0 to 9
    sum := sum + close[i]

PineTS:

let sum = 0.0;
for (let i = 0; i < 10; i++) {
    sum += close[i];
}

Control Structures

Switch Statement

PineTS supports the JavaScript switch statement, which is equivalent to Pine Script's switch.

Pine Script:

switch type
    "ema" => ta.ema(close, len)
    "sma" => ta.sma(close, len)
    => ta.rma(close, len)

PineTS:

switch (type) {
    case 'ema':
        return ta.ema(close, len);
    case 'sma':
        return ta.sma(close, len);
    default:
        return ta.rma(close, len);
}

Functions

User-defined functions in PineTS are written as standard JavaScript functions.

Pine Script:

f_ma(source, length) =>
    ta.sma(source, length)

PineTS:

function f_ma(source, length) {
    return ta.sma(source, length);
}

Tuples and Multiple Return Values

Pine Script allows functions to return multiple values (tuples). PineTS handles this using array destructuring.

Pine Script:

[macdLine, signalLine, histLine] = ta.macd(close, 12, 26, 9)

PineTS:

const [macdLine, signalLine, histLine] = ta.macd(close, 12, 26, 9);

Series and History Access

Accessing historical values is done using the [] operator in Pine Script. In PineTS, array access syntax is supported and transpiled to safe series access.

Feature	Pine Script	PineTS (JS/TS)	Notes
Current Value	close	close	References the current bar's value.
Previous Value	close[1]	close[1]	References the value 1 bar ago.
History Access	close[10]	close[10]	References the value 10 bars ago.

PineTS:

// Calculate momentum
let mom = close - close[10];

Conditional Logic

PineTS supports standard JavaScript control flow, which maps to Pine Script's execution model.

Feature	Pine Script	PineTS (JS/TS)	Notes
If Statement	if condition     ...	if (condition) {     ... }	Standard JS syntax.
Ternary	cond ? val1 : val2	cond ? val1 : val2	Standard JS syntax.

Example: Trend Direction

Pine Script:

if close > open
    direction := 1
else
    direction := -1

PineTS:

if (close > open) {
    direction = 1;
} else {
    direction = -1;
}

Built-in Variables

PineTS exposes Pine Script's built-in variables through the context object, but usually, you destructure them for easier access.

Variable	Pine Script	PineTS (JS/TS)
Close Price	close	close (from context.data)
Open Price	open	open (from context.data)
High Price	high	high (from context.data)
Low Price	low	low (from context.data)
Volume	volume	volume (from context.data)
Bar Index	bar_index	bar_index (from context.pine)

PineTS Setup:

const { close, high, low } = context.data;
const { bar_index } = context.pine;

Functions and Namespaces

PineTS organizes built-in functions into namespaces similar to Pine Script v5.

Namespace	Pine Script	PineTS (JS/TS)	Example
Technical Analysis	ta.*	ta.*	ta.sma(close, 14)
Math	math.*	math.*	math.max(high, low)
Request	request.*	request.*	request.security(...)

PineTS Setup:

const { ta, math } = context.pine;
// Usage
const sma = ta.sma(close, 14);

Full Example: Parabolic SAR

This example demonstrates var for state, if/else logic, and history access.

Pine Script:

pine_sar(start, inc, max) =>
    var float result = na
    var float maxMin = na
    var float acceleration = na
    var bool isBelow = false
    bool isFirstTrendBar = false

    if bar_index == 1
        if close > close[1]
            isBelow := true
            maxMin := high
            result := low[1]
        else
            isBelow := false
            maxMin := low
            result := high[1]
        isFirstTrendBar := true
        acceleration := start

    // ... logic continues ...
    result

PineTS:

function pine_sar(start, inc, max) {
    // Use 'var' for state variables (persistent)
    var result = na;
    var maxMin = na;
    var acceleration = na;
    var isBelow = false;

    // Use 'let' for temporary variables (reset every bar)
    let isFirstTrendBar = false;

    if (bar_index == 1) {
        if (close > close[1]) {
            isBelow = true;
            maxMin = high;
            result = low[1];
        } else {
            isBelow = false;
            maxMin = low;
            result = high[1];
        }
        isFirstTrendBar = true;
        acceleration = start;
    }

    // ... logic continues ...

    return result;
}