Pine Script Development

Critical Syntax Rules

• Ternary operators MUST stay on one line — splitting across lines causes "end of line without line continuation" error. For complex ternaries, use intermediate variables:

  isBull = close > open
  barColor = isBull ? color.green : color.red
  

• Continuation lines MUST be indented MORE than the starting line — same indentation = error
• NEVER use plot() inside local scopes (if/for/functions) — use conditional value instead: plot(condition ? value : na)
• barstate.isconfirmed — use to prevent repainting on real-time bars

Platform Limits

500 bars history for request.security() | 500 plot calls | 64 drawing objects | 40 request.security() calls | 100KB compiled size

Performance

• Tuple security calls — one request.security() returning [close, high, low] instead of 3 separate calls
• Pre-allocate arrays with array.new<type>(size) instead of push-and-resize
• Short-circuit signals: build conditions incrementally, exit early when first condition fails
• Cache repeated calculations in variables — Pine recalculates every bar

Debugging

TradingView has no console or debugger. Use these patterns:

• Label debugging: label.new(bar_index, high, str.tostring(myVar)) to inspect values
• Table monitor: table.new() with barstate.islast for real-time variable dashboard
• Debug mode toggle: wrap all debug code in if input.bool("Debug", false) — remove before publishing
• Repainting detector: track previousValue = value[1], flag when historical values change

Strategy & Backtesting

• Use strategy.* functions: strategy.wintrades, strategy.losstrades, strategy.grossprofit
• Drawdown tracking: maxEquity = math.max(strategy.equity, nz(maxEquity[1])), then dd = (maxEquity - strategy.equity) / maxEquity * 100
• Sharpe: dailyReturn * 252 / (stdDev * math.sqrt(252))
• Walk-forward validation — optimize on period 1, test on period 2, re-optimize on period 2, test on period 3. If metrics degrade > 30%, parameters are overfit.
• Indicator accuracy testing — use forward-looking close[lookforward] to measure prediction accuracy, track true/false positive rates

Visualization

• color.from_gradient() for trend strength coloring
• Adaptive text sizing: size.small for intraday, size.normal for daily+
• Dynamic table rows — resize based on enabled features via input toggles
• Professional color constants: define BULL_COLOR, BEAR_COLOR, NEUTRAL_COLOR once with transparency

Publishing

• Documentation goes at TOP of .pine file as comments before indicator()/strategy()
• Use @version, @description, @param tags
• Multi-line tooltips: tooltip="Line 1" + "\n" + "Line 2"
• TradingView House Rules: no financial advice, no performance guarantees, no external links, no obfuscated code, no donation requests

Anti-Patterns

• Indicator stacking (RSI + Stochastics + CCI) — all measure the same thing (momentum). Use indicators from different categories instead.
• Trading divergence without structure confirmation — wait for break above prior swing high before entry, divergence alone can persist far longer than expected
• Overfitting signals: if optimal parameters are oddly specific (RSI 23 instead of 20), the backtest is curve-fitted. Use round numbers.
• Treating support/resistance as exact prices — they are zones (crypto 1-3%, forex 20-50 pips)

Workflow

1. Write indicator/strategy in Pine Editor
2. Test with bar replay and strategy tester on multiple timeframes
3. Walk-forward validate before trusting backtest results
4. Verify: run on 3+ symbols and 2+ timeframes. If metrics degrade >30%, parameters are overfit.