Language Reference

Overview

This is the compact lookup page for Echo syntax and built-ins.

Statements

name: str = "Echo";
name = "Echo 2";
if cond { ... }
while cond { ... }
for i: int in 0..10 { ... }
foreach item: str in items { ... }
fn greet(name: str) { ... }
return;
break;
continue;
use name;
use mut count;
watch count;

Built-in Types

• int
• float
• str
• bool
• dynamic
• list
• hash
• void for function return annotations only

Literals

• Integers: 123
• Floats: 12.34
• Strings: "hello", 'hello'
• Booleans: true, false
• Null: null
• Lists: [1, 2, 3]
• Hashes: { key: value }

Operators

• Arithmetic: + - * / %
• Comparison: == != < > <= >=
• Logical: && || !
• Assignment: =

Function Forms

fn name(a: int) { ... }
fn name(a: int) -> int { ... }
fn square(x: int) => x * x;
fn square(x: int) -> int => x * x;

If a function contains return, it must declare a return type.

Notes

Use this page for quick lookup. For explanations and examples, go back to the guide pages.

See Also

• Built-in Methods
• Operators
• Variables and Types