OS1xxx Syntax errors

Unexpected character char. suggestion

What it means

You typed a character that the language does not use outside a string or a comment. Often you cannot see it: a no-break space or a curly quotation mark arrives with code copied from a web page, a chat message or a document, and it looks exactly like a normal space or quote. The rest are operators typed out of habit, such as !, &&, ||, ^, ** and ++, or braces around a block. The message quotes the character and names the replacement. For an invisible or unusual character it also gives the Unicode number, such as U+00A0, and for spaces, tabs and quotation marks a name such as "a no-break space". A tab at the start of a line is OS1002 instead.

When the character is invisible, delete the text around the reported column and type it again by hand. For a pasted string, retyping its two quotes is usually enough. A # typed to start a comment lands here too: comments start with //.

How to fix it

Delete the character or replace it with the plain ASCII spelling the message names: a plain space for a non-breaking space, a straight quote for a typographic one, not for !, and for &&, or for ||, pow(a, b) for ^.

if !ready
    signal("BUY")

if not ready
    signal("BUY")

written is not a colour: a colour literal is # and six or eight hexadecimal digits.

What it means

A # followed by hexadecimal digits is a colour, and it needs exactly six digits, as in #ff8800, or eight, where the last two set the transparency, as in #ff880080. The short forms #fff and #ff88 are not accepted, and neither is a character outside 0 to 9 and a to f (capitals A to F are fine). Because the colour is dropped from the line, the console usually shows OS1022 beside this error; correcting the colour clears both. If hex digits are not what you want, a named colour such as orange or rgb() says the same thing.

This is the case of OS1001 for colours. It has its own code because deleting the #, the advice OS1001 gives, would throw away a colour you nearly had right.

How to fix it

Give it six hexadecimal digits, or eight where the last two are the alpha byte. A named colour or rgb(r, g, b) says the same thing without the digits.

plot(close, "Close", #ff88)

plot(close, "Close", #ff8800)

written is neither a number nor a name: the number literal ends at number, and a name cannot begin with a digit.

What it means

A name cannot start with a digit, and a number cannot have letters attached to it. The usual causes are a variable called something like 2fast, a unit typed after a quantity (10k, 5m), a binary or octal literal (0b1011, 0o17), and an underscore at the end of a number (1_000_). Numbers are written in decimal, such as 1_000_000 or 2.5e-4, or in hexadecimal with 0x, and an underscore may only sit between two digits.

Rename the variable so it starts with a letter (fast2), and write quantities in full: 10000, not 10k. When you meant a number followed by a name, put an operator between them.

How to fix it

Write the value in a form the language has: a decimal literal, or 0x and hexadecimal digits. There is no binary form and no octal form, and an underscore separates digit groups only where a digit follows it. Where a number and a name were meant as two things, put an operator between them.

mask = 0b1011

mask = 0x0b

This string literal opens with quote and the line ends before a matching quote.

What it means

A string opens and closes on the same line, with the same kind of quote: "BUY" or 'BUY'. This error is reported at the opening quote when the line ends before a matching one, which almost always means the closing quote is missing. The unclosed string also swallows the ) of the call it sits in, so OS1012 usually appears beside it and goes away when the quote is added.

A string cannot span lines. To build a long message, close each piece and join them with +, ending the line with the + so the statement continues.

How to fix it

Close the string with a matching quote before the end of the line, and join text across lines with + and a continuation.

signal("BUY)

signal("BUY")

sequence is not an escape sequence.

What it means

Inside a string, a backslash starts an escape sequence: \n for a new line, \t for a tab, \r, \0, \\ for a backslash, \" and \' for quotes, and \u followed by exactly four hexadecimal digits for any character, such as \u20b9 for the rupee sign. A backslash followed by anything else is refused rather than guessed at. It most often comes from a file path or a pattern pasted with single backslashes: write each backslash as \\.

How to fix it

Double the backslash to write one literally, or use one of the escapes the language defines.

path = "C:\data\bars"

path = "C:\\data\\bars"

marker does not open or close a comment. A comment is written // and runs to the end of its line.

What it means

OpenScript has line comments only: // starts one and it runs to the end of the line. /* and */ are not comment markers, so the compiler reports them where they sit instead of letting an unclosed comment hide the rest of the file. To comment out several lines, put // at the start of each one.

How to fix it

Write // instead, and give every line of a commented region its own //, which every editor does with one keystroke.

lookback = 14 /* bars */

lookback = 14 // bars

; is not part of the language.

What it means

A statement ends at the end of its line, so there is nothing for a semicolon to do, and a semicolon at the end of a line is refused as well as one between two statements. Delete it, and give each statement a line of its own.

How to fix it

Delete the; and put the second statement on its own line.

fast = ema(close, 9); slow = ema(close, 21)

fast = ema(close, 9)
slow = ema(close, 21)

This line is indented with a tab.

What it means

The line is indented with a tab. A tab is drawn at a different width in every editor, so a block marked with tabs could mean one thing on your screen and another on someone else's, and the language accepts spaces only. In the /trading editor the Tab key moves the focus out of the editor rather than typing anything, so a tab almost always arrives in pasted code. Replace each leading tab with four spaces.

How to fix it

Replace the leading tabs with spaces. Four spaces per level is the convention and the formatter's output.

if close > open
	signal("UP")

if close > open
    signal("UP")

This line is indented found spaces; the block opened at line line is indented expected.

What it means

Every line of one block must start at exactly the same column, and a single space more or less counts. The message says how many spaces this line has, how many its block has, and which line opened the block. Line it up with the lines above it to keep it in the block, or with the header to end the block there.

A continued statement, one that carries on from the line above because of an open bracket or a trailing operator, follows a different rule: see OS1028.

How to fix it

Indent this line to expected spaces to keep it in the block, or to line's own indentation to end the block here.

if trending
    body = close - open
     wick = high - low

if trending
    body = close - open
    wick = high - low

A continuation line must be indented more deeply than the line its statement began on; line line is indented statement and this line is indented found.

What it means

A statement continues onto the next line when a bracket is still open, when the line ends with an operator, a comma, ?, : or =, or when it ends with a backslash. The continued line must be indented further than the line the statement began on, so that nobody reading the file can mistake it for a new statement. Indent it; any amount deeper than the first line works, and lining it up under the opening bracket reads well.

This is the case of OS1003 for continued lines. It has its own code because a continuation opens no block, so the block rule's message would describe a block that is not there.

How to fix it

Indent this line further than the statement spaces on line line. Four more is the convention and the formatter's output.

total = ema(close, 9) +
ema(close, 21)

total = ema(close, 9) +
        ema(close, 21)

header opens a block, and the next line is not indented more deeply.

What it means

A header line promises an indented body, and the next line is not indented more deeply. This is nearly always a body that lost its indentation when it was pasted. Indent the body under the header.

if, else, the loops, case and default have no one-line form, so even a body of one statement goes on its own indented line. A function can be written on one line by putting its body after =>: fn barRange() => high - low. Blank and comment lines do not count as a body.

How to fix it

Indent the body under the header, or delete the header line if the body is genuinely empty.

if crossUp(fast, slow)
signal("BUY")

if crossUp(fast, slow)
    signal("BUY")

This else is indented found spaces and the nearest if is indented expected.

What it means

An else belongs to the if at exactly its own indentation. At any other indentation there is no if for it to pair with, and the compiler does not guess which one you meant. Line the else up with its if. An else if is written as two words on one line and is not indented further than the if.

An else with no if above it at all, such as one written after a for block, is reported the same way. When the else is indented by a stray space or two, OS1003 usually appears on the same line; lining it up clears both.

How to fix it

Line the else up with its if, at expected spaces.

if trending
    signal("BUY")
  else
    signal("WAIT")

if trending
    signal("BUY")
else
    signal("WAIT")

The bracket opened at line line is never closed.

What it means

An open ( or [ carries the statement onto the following lines, so when its closer is missing the compiler reads everything after it as part of one long statement. The error is reported at the opening bracket, which is where to look. It usually brings a crowd of other errors from the lines below, such as a continuation that is not indented or a missing comma; add the closer and they go with it. Reading an error shows one missing bracket producing six diagnostics.

How to fix it

Add the matching closer at the end of the argument list on line line.

plot(ema(close, 9), "EMA", aqua

plot(ema(close, 9), "EMA", aqua)

Found found where expected was expected, closing the opener opened at line line.

What it means

A call closes with ), and a history index or an array closes with ]. This error means a bracket was closed with the other kind, such as sum(values] or close[1). The message names the bracket it found, the one it expected and the line the opener is on. Change the closer to match its opener.

How to fix it

Change found to expected, which is what closes the opener opened at line line.

total = sum(closes]

total = sum(closes)

Two arguments run together; a comma is missing before token.

What it means

Two values sit side by side inside a call with no comma between them. It usually comes from editing a call: a comma deleted by accident, as in plot(ema(close, 9) "EMA", aqua), or a named argument added without one, as in plot(close, "C" color = aqua). Put the comma back. The compiler reports it rather than guessing where the comma should go.

How to fix it

Put a comma between the two arguments.

plot(ema(close, 9) "EMA", aqua)

plot(ema(close, 9), "EMA", aqua)

An expression was expected after token.

What it means

A line ends with something that needs more after it (an operator, a comma, = or an opening bracket) and nothing usable follows. It is usually a half-finished edit, or a stray + or , left at the end of a line. Supply the missing value, or delete the trailing symbol.

It also appears beside another error on the same line when that error removed part of the expression, as with a malformed colour (OS1027). Fix the other error first.

How to fix it

Supply the missing operand, or delete the trailing token.

len = input(14, "Length") +

len = input(14, "Length")

This ? has no matching :

What it means

The conditional operator, condition ? a : b, always produces a value, so it needs both of its arms. A one-armed version is usually a plot meant to draw on some bars only. Use none for the arm that should draw nothing: plot(ready ? value : none, "Value", aqua). A plot draws a gap wherever its value is none.

How to fix it

Give the ternary both arms, and use none for the arm that should draw nothing.

plot(ready ? value, "Value", aqua)

plot(ready ? value : none, "Value", aqua)

A comparison cannot be chained: op1 is already applied before op2.

What it means

30 < r < 70 reads naturally, but it can be read two ways, and a language that places orders does not guess. An expression holds at most one comparison, and that applies to == and != as much as to < and >. Split it with and, writing the middle value twice: 30 < r and r < 70.

The console usually shows OS2003 on the same line as well, because the first comparison produces a bool and the second then compares that bool with a number. Splitting the comparison clears both.

How to fix it

Split it with and, naming the middle value twice: a < b and b < c.

if 30 < r < 70
    zone = "mid"

if 30 < r and r < 70
    zone = "mid"

Unexpected token after the end of this statement.

What it means

The compiler finished reading a statement and found more on the same line. Either an operator is missing between two values (x = close open), there is one closing bracket too many (ema(close, 9))), or two statements share a line. Add the operator you meant, delete the extra bracket, or move the second statement to its own line.

How to fix it

Put token and what follows it on its own line, or supply the operator that was meant to join them.

fast = ema(close, 9) slow = ema(close, 21)

fast = ema(close, 9)
slow = ema(close, 21)

= assigns a value, and a condition needs a comparison.

What it means

= stores a value and == compares two. A condition needs a comparison, so if len = 14 is refused instead of quietly storing 14 and treating the test as true. The same applies to a while condition. Write ==, or, if you did mean to store a value, do it on its own line above the if.

How to fix it

Write == to compare, or move the assignment to its own line above the if.

if len = 14
    signal("DEFAULT")

if len == 14
    signal("DEFAULT")

word is only valid inside a for or a while body.

What it means

break leaves the innermost for or while loop, and continue skips to its next pass. Outside a loop body there is nothing for either to act on. To leave a function early, use return. To skip some work on some bars, put that work under an if; plots stay at the top level and take none on the bars they should skip.

How to fix it

Move it inside the loop body, or write return to leave a function early.

fn firstAbove(values, mark) =>
    if size(values) == 0
        break
    values[0]

fn firstAbove(values, mark) =>
    if size(values) == 0
        return none
    values[0]

var name has no initial value.

What it means

var declares a value that keeps its content from one bar to the next, and its starting value is part of the declaration, so no bar can ever read it empty by accident. Write var total = 0 to start from zero, or var runningHigh = none to start with no value and fill it on a later bar. See Persistence.

How to fix it

Give it a starting value; var name = none is the empty start.

var runningHigh
if high > orElse(runningHigh, high)
    runningHigh = high

var runningHigh = none
if isNone(runningHigh) or high > runningHigh
    runningHigh = high

word is only valid inside a switch, and default must be its last arm.

What it means

case and default are the arms of a switch and exist only inside one, indented under it. default catches everything the cases above it did not, so it must be the last arm: a case after it could never run. Move the arms under their switch, with default at the bottom.

How to fix it

Move the arm inside the switch block, and put default after every case.

switch method
    default
        len = 14
    case "fast"
        len = 9

switch method
    case "fast"
        len = 9
    default
        len = 14

word is a reserved word and cannot be used as a name.

What it means

Reserved words belong to the language and cannot name a variable, a function or a function parameter. The ones people reach for most often are color, step, type, in and number. A few, such as type, map and import, are reserved for features planned for later versions, so that adding those features cannot break a script written today. The fix suggests a name that keeps your meaning, such as colorValue. The full list is on Keywords.

A named argument label is not a variable, so plot(x, "X", color = aqua) is fine. Writing bool(x) or number(s) to convert a value lands here too, because the conversions are toBool() and toNumber().

How to fix it

Rename it; suggestion keeps the meaning and is not reserved.

type = input("fast", "Mode", options = ["fast", "slow"])

mode = input("fast", "Mode", options = ["fast", "slow"])

A for header needs = start to end or in array; found token.

What it means

A for loop has two forms and no others. A counted loop names a start and an end, for i = 0 to 9, optionally followed by step, and runs with both ends included. A loop over an array names the array, for price in prices. A comma between the bounds, or a header with no to, is this error. See Control flow.

How to fix it

Write for i = 0 to size(values) - 1 for a counted loop, or for v in values to visit elements.

for i = 0, 9
    total += close[i]

for i = 0 to 9
    total += close[i]

version must be the first line that is not blank and not a comment; line line came before it.

What it means

version 1 must be the first line of the file, above the study() or strategy() declaration. Only blank lines and comments may come before it. The version is read before anything else so that the script is always compiled by the right version of the language. Move the line to the top.

How to fix it

Move the version line to the top of the file, above the study or strategy declaration.

study("EMA cross")
version 1

version 1

study("EMA cross")

fn name is declared inside a block, and a function is declared at the top level of the file.

What it means

Functions are declared at the top level of the file, never inside an if, a loop, a switch arm or another function. Move the whole fn declaration out to the top level and call it from inside the block. A function may be called on a line above its declaration, so it can sit anywhere at the top level. See User functions.

How to fix it

Move the whole declaration out to the top level of the file, and call name from inside the block.

if trending
    fn smoothed(src) => sma(src, 9)
    plot(smoothed(close), "Smooth", aqua)

fn smoothed(src) => sma(src, 9)

smooth = smoothed(close)
plot(trending ? smooth : none, "Smooth", aqua)

An assignment writes to a name, and this target is an index into name.

What it means

There is no assignment into brackets. On an array, change an element with set(): set(prices, 0, close). On a series such as close, [1] reads a bar the engine has already computed, and a past bar can never be rewritten. If you want a value of your own, assign it to a plain name.

How to fix it

Change an array element with set(name, i, v), or assign to a plain name: the past of a series is computed and never written.

var prices = [0.0]
prices[0] = close

var prices = [0.0]
set(prices, 0, close)

An assignment writes to a name, and this target is the member member of name.

What it means

A dot reads a member of a namespace such as chart, bar or session, and every member is a fact supplied by the library, the instrument or the position. A script cannot write to any of them, and version 1 has no user-defined records whose fields you could set. Assign the value to a plain name of your own: tick = 0.05, not chart.tickSize = 0.05. When the member does not exist either, OS2009 appears beside this error, as it does for the example below: chart has a tickSize member, not tickStep.

Related. Reading an error, Script structure, Keywords, Operators, Control flow, OS2xxx Names and types

How to fix it

Assign to a plain name. Version 1 has no member assignment: a dot reads a member, and the members a script can reach are facts and functions the library and the host supply.

chart.tickStep = 0.05
plot(close + chart.tickStep, "Stepped", aqua)

tickStep = 0.05
plot(close + tickStep, "Stepped", aqua)