Operators and expressions

An expression combines values into a new value. This page lists every operator Lipi has, and two that people expect and it does not have.

Arithmetic

- is also the negation operator, written in front of a single expression.

There is no exponentiation operator

^ is not an operator in Lipi. A script containing it does not parse.

Comparison

Each of these produces a bool.

Logical operators have two spellings

Each logical operator can be written as a symbol or as a word. The two spellings are the same token, so the choice is one of house style and nothing else. There is no difference in behaviour to weigh up.

bool up = close > close[1] and close > 0
bool upAgain = close > close[1] && close > 0

Pick one spelling for a script and keep to it.

Choosing between two values

The conditional expression takes a condition and two values, and produces one of them.

color shade = close > close[1] ? #188A6B : #A6323C

Use this rather than a branch when what you want is a value. Chart output functions have to be called at the top level of a script, so a condition that decides how something looks belongs in an argument, not around the call.

Declaring and reassigning

Two operators assign, and they do different jobs.

A declaration is an optional data type, a name, =, and an expression. It may also open with a keyword that decides whether the value survives from one bar to the next; that keyword is covered with persistence.

Five compound assignments are accepted: +=, -=, *=, /= and %=.

float total = close
total := total + close[1]
total += close[2]

Mathematical constants

Four constants are published. Each is a const float.

A complete script

indicator("Percent change", "pct", false)
float previous = close[1]
float change = close - previous
float pct = change / previous * 100
plot(pct)