Hashes

Overview

Hashes are Echo's mutable key-value maps.

Syntax

user: hash = { name: "Echo", active: true };
name: str = user["name"];
user["active"] = false;

Example

user: hash = { name: "Ada", active: true };
user["role"] = "admin";
say(user);
say(user.keys());

Output

{"name": "Ada", "active": true, "role": "admin"}
["name", "active", "role"]

Notes

• Hash literal keys can be identifiers or string literals.
• Bare identifier keys become string keys.
• Runtime indexing requires a string key.
• ensure() is useful for bucket-building and counters.
• take() and take_last() mutate the hash.

Common Mistakes

• Using non-string keys in runtime indexing
• Expecting missing keys to return null
• Forgetting that take() removes the key

Current Limitation

• Hash indexing only accepts string keys.
• Key-value types are not generic.

See Also

• Built-in Methods
• Type Aliases
• Hash Usage