Case Sensitivity

Understanding case sensitivity is crucial for writing functional HaasScript code. HaasScript treats uppercase and lowercase letters as distinct characters, which affects variables, functions, and commands.

HaasScript is Case-Sensitive

HaasScript distinguishes between uppercase and lowercase letters. This means:

local myVariable = 10
local MyVariable = 20
local MYVARIABLE = 30

-- These are THREE DIFFERENT variables
Log(myVariable)   -- Outputs: 10
Log(MyVariable)   -- Outputs: 20
Log(MYVARIABLE)   -- Outputs: 30

Commands and Functions

All HaasScript commands and built-in functions use specific capitalization. You must match the exact casing.

Correct vs Incorrect

-- Correct: Exact capitalization
local rsi = RSI(ClosePrices(), 14)
local sma = SMA(ClosePrices(), 20)
local ema = EMA(ClosePrices(), 20)

-- Incorrect: Wrong capitalization causes errors
local rsi = rsi(ClosePrices(), 14)      -- Error: rsi is not defined
local sma = sma(ClosePrices(), 20)      -- Error: sma is not defined
local ema = ema(ClosePrices(), 20)      -- Error: ema is not defined

Trading Functions

-- Correct capitalization
DoLong("Entry signal")
DoShort("Exit signal")
DoExitPosition("Close position")

-- Incorrect
dolong("Entry signal")      -- Error: function not found
Doshort("Exit signal")      -- Error: function not found
doexitposition("Close")     -- Error: function not found

Risk Management Functions

-- Correct
StopLoss(2.0)
TakeProfit(5.0)
TrailingStopLoss(1.5)

-- Incorrect
stoploss(2.0)           -- Error
takeprofit(5.0)         -- Error
trailingstoploss(1.5)   -- Error

Signal Constants

HaasScript signal constants use PascalCase (first letter uppercase, subsequent words capitalized):

-- Correct signal constants
SignalLong
SignalShort
SignalExitLong
SignalExitShort
SignalExitPosition
SignalNone

-- Incorrect
signalLong        -- Error
signallong        -- Error
SIGNAL_LONG       -- Error
signallong        -- Error

Data Type Names

HaasScript type names use PascalCase:

-- Correct
NumberType
ListNumberType
StringType
BoolDataType
EnumType

-- Incorrect
numberType       -- Error
listnumberType   -- Error
string_type      -- Error

Variable Naming Conventions

While HaasScript is case-sensitive, you should follow consistent naming conventions:

camelCase for Variables

-- Recommended: camelCase (first letter lowercase)
local closePrices = ClosePrices()
local rsiValue = RSI(ClosePrices(), 14)
local stopLossPercentage = 2.0

-- Also valid but less common
local ClosePrices = ClosePrices()  -- Very bad! Overwrites built-in function!
local RSIValue = RSI(ClosePrices(), 14)

PascalCase for Custom Commands

-- Custom commands typically use PascalCase
DefineCommand("MyCustomIndicator", "Description here")
DefineCommand("CalculateEntrySignal", "Entry signal calculator")

Common Case Sensitivity Mistakes

Mixing Up Similar Variable Names

-- Confusing: Variables differ only by case
local price = CurrentPrice()
local Price = CurrentPrice()
local PRICE = CurrentPrice()

-- Better: Use descriptive, distinct names
local currentPrice = CurrentPrice()
local entryPrice = CurrentPrice()
local targetPrice = CurrentPrice()

Inconsistent Command Capitalization

-- Error: Inconsistent capitalization
local rsi = RSI(ClosePrices(), 14)
local sma = Sma(ClosePrices(), 20)  -- Error: should be SMA
local ema = EmA(ClosePrices(), 20)  -- Error: should be EMA

-- Correct: Consistent capitalization
local rsi = RSI(ClosePrices(), 14)
local sma = SMA(ClosePrices(), 20)
local ema = EMA(ClosePrices(), 20)

Wrong Signal Constants

-- Error: Wrong case
if signal == signallong then  -- Error
    DoLong()
end

-- Correct: Proper capitalization
if signal == SignalLong then
    DoLong()
end

String Literals

Strings in quotes are case-sensitive:

local message = "Hello"
local MESSAGE = "HELLO"
local Message = "Hello"

-- These are DIFFERENT strings
Log(message)  -- Outputs: Hello
Log(MESSAGE)  -- Outputs: HELLO
Log(Message)  -- Outputs: Hello

This matters when comparing string values:

local signal = "Long"

-- This condition is FALSE (case mismatch)
if signal == "long" then
    DoLong()
end

-- This condition is TRUE (exact match)
if signal == "Long" then
    DoLong()
end

Input Field Labels

Input field labels are strings and are case-sensitive:

local rsiPeriod = Input("RSI Period", 14)
local rsiPeriod2 = Input("rsi period", 14)
local rsiPeriod3 = Input("RSI PERIOD", 14)

-- These create THREE DIFFERENT input fields due to different casing

However, HaasScript can handle multiple input fields with the same label without issues:

-- This works fine - three separate input fields
local rsiPeriod = Input("RSI Period", 7)
local rsiPeriod2 = Input("RSI Period", 14)
local rsiPeriod3 = Input("RSI Period", 21)

-- Each variable gets its correct value
-- The underlying system distinguishes between them automatically

While this won't break anything, it can be confusing. Consider using descriptive labels when you have multiple similar inputs:

-- Clearer: Different labels for different purposes
local fastRsiPeriod = Input("Fast RSI Period", 7)
local slowRsiPeriod = Input("Slow RSI Period", 14)
local signalRsiPeriod = Input("Signal RSI Period", 21)

Best Practices

1. Use Consistent Naming

-- Good: Consistent camelCase
local closePrices = ClosePrices()
local rsiValue = RSI(ClosePrices(), 14)
local macdSignal = MACD(ClosePrices(), 12, 26, 9)

-- Avoid: Inconsistent capitalization
local closePrices = ClosePrices()
local RSIValue = RSI(ClosePrices(), 14)
local MacdSignal = MACD(ClosePrices(), 12, 26, 9)

2. Match Command Names Exactly

-- Always use exact command capitalization
RSI()
SMA()
EMA()
DoLong()
DoShort()
StopLoss()
TakeProfit()

-- Never use variations - unless you defined them yourself
rsi()
sma()
ema()
dolong()
doshort()
stoploss()
takeprofit()

3. Be Careful with String Comparisons

-- Good: Use exact string matching
local signal = "Long"
if signal == "Long" then
    DoLong()
end

-- Better: Use signal constants when viable
local signal = SignalLong
if signal == SignalLong then
    DoLong()
end

4. Avoid Confusing Variable Names

-- Bad: Too similar, easy to confuse
local price = 100
local Price = 200
local PRICE = 300

-- Good: Distinct, descriptive names
local entryPrice = 100
local exitPrice = 200
local targetPrice = 300

Troubleshooting Case Sensitivity Errors

"Function not found" or "Command not found"

If you get these errors, check the capitalization:

-- Error: Unknown references: rsi
local rsi = rsi(ClosePrices(), 14)

-- Fix: Use correct capitalization
local rsi = RSI(ClosePrices(), 14)

"Variable not defined" or "Variable is nil"

-- Error: Unknown references: MyValue
local myValue = 10
Log(MyValue)  -- Wrong case!

-- Fix: Use exact variable name
local myValue = 10
Log(myValue)

Unexpected behavior with strings

-- Problem: String comparison fails
local market = "BTC_USDT"
if market == "btc_usdt" then  -- This will be false
    DoLong()
end

-- Fix: Match case exactly
local market = "BTC_USDT"
if market == "BTC_USDT" then
    DoLong()
end

Quick Reference

Category	Convention	Example
Variables	camelCase	local myValue = 10
Built-in Commands	PascalCase	RSI(), SMA(), DoLong()
Custom Commands	PascalCase	MyCustomCommand()
Signal Constants	PascalCase	SignalLong, SignalShort
Data Types	PascalCase	NumberType, EnumType
Strings	Exact match	"Long" ≠ "long"

Summary

• HaasScript is case-sensitive - uppercase and lowercase are different
• Match exact command names - RSI() not rsi()
• Use consistent naming conventions - camelCase for variables, PascalCase for commands
• Be careful with string comparisons - "Long" ≠ "long"
• Avoid confusing variable names - Don't use names that differ only by case

Following these rules will prevent common errors and make your code more readable and maintainable.