Common mistakes

This page is for people learning Echo. It explains problems in ordinary language.

Looking for error codes (E1001, E2003, …)? Use Errors and Troubleshooting.

For each problem:

What you see → What it means → Why → How to fix → Try again

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Missing semicolon

What you see

A message like: Expected ;, got end of input (or similar).

What it means

Echo reached the end of an instruction and did not find ;.

Why it happened

You wrote something like:

say("Hello, Echo!")

How to fix

Add ; at the end:

say("Hello, Echo!");

Try again

Run the fixed program. You should see Hello, Echo!.

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Variable used before it was declared

What you see

Something like: Variable 'count' is not declared (often E1011), with a hint to declare with a type.

What it means

You tried to assign to a name Echo has not been introduced to yet.

Why it happened

count = 1;

How to fix

Declare it the first time, with a type:

count: int = 1;

Try again

count: int = 1;
say(count);

Should print 1.

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Wrong type of value

What you see

A type error when you assign or pass a value (message mentions types or E codes in the Type category).

What it means

The name was declared for one kind of value (for example int), but you gave it another kind (for example text).

Why it happened

count: int = 1;
count = "two";

How to fix

Keep the same kind, or declare a different variable for text:

count: int = 1;
count = 2;
label: str = "two";

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elang: command not found

What you see

The Terminal says it does not know the command elang.

What it means

Your computer is not finding the Echo install in this Terminal window.

Why it happened

Common causes: install not finished, or you did not open a new Terminal after pipx ensurepath.

How to fix

1. Open a new Terminal window.

2. Run elang --version again.

3. If it still fails, re-run:

   python3 -m pipx ensurepath

   (Windows PowerShell: python -m pipx ensurepath), then open another new Terminal.

4. Check pipx list mentions echolang.

Still stuck? On macOS/Linux, developers sometimes need ~/.local/bin on PATH — see the longer checklist in Install Echo.

Try again

Success looks like:

Echo 2.2.1

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File not found when running

What you see

Echo (or the shell) says it cannot find hello.echo (or similar).

What it means

Terminal is looking in a folder that does not contain your file.

How to fix

1. Note where you saved the file (Desktop, Documents, …).
2. cd into that folder.
3. Confirm the file name ends with .echo.
4. Run elang hello.echo again.

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Missing { } after if / while

What you see

A syntax error near if or while.

What it means

Echo expects braces around the block.

How to fix

if true {
    say("yes");
}

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Changing an outer variable inside a function

What you see

An error about assignment / E2003, often mentioning use mut.

What it means

Inside a function you may read a name from outside. To change it, Echo requires use mut first.

How to fix (when you need it)

count: int = 0;

fn bump() {
    use mut count;
    count = count + 1;
}

bump();
say(count);

Beginners can avoid this pattern: pass values in as parameters and return new values instead. Full rules: Scope, use, and watch.

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Next

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• Full catalog: Errors and Troubleshooting