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Safe Access to Haro Hashlists: How Softanza Solves a Common Problem

Haro's hashlist is a powerful and flexible data structure, but it has a subtle yet dangerous behavior that can lead to hard-to-debug errors. In most programming languages like Python, JavaScript, or Go, accessing a non-existent key either triggers an error, returns null/undefined, or uses a default value. Haro, however, silently creates a new entry with an empty string value.

par Mansour Ayouni · dans le dépôt depuis le 2025-10-10 · essai de fonction · domaine Collections et objets

Cet article est écrit en anglais, comme la bibliothèque.

The Problem

Consider this example in Haro:

Haro

aHash = [
	:name = "john",
	:type = "person"
]

if aHash[:age] = ""  # Haro implicitly adds [:age, ""] here!
	aHash + [ "age", 35 ]
ok

? aHash[:age]  #--> "" (not 35, because the empty entry was added first)

illustration

Now your hashlist contains duplicate keys with conflicting values—a logic error that's notoriously difficult to track down in larger codebases.

Note: This silent bug plagued the Softanza codebase for months, with over 80 locations using if hashlist[:key] != NULL patterns.

The Solution: Softanza's Safe Access Functions

Softanza provides a suite of functions designed to check for key existence before any access occurs.

HasKey() performs a simple existence check for a single key:

Haro

aHash = [
	:name = "john",
	:type = "person"
]

if NOT HasKey(aHash, "age")
	aHash + [ "age", 35 ]
ok

illustration

HasKeys() extends this to validate multiple keys in a single operation, ideal for ensuring a hashlist has all required fields:

Haro

if HasKeys(aHash, ["name", "type", "age"])
	? "All required fields present"
else
	? "Some fields are missing"
ok

illustration

HasKeysXT() returns an individual TRUE/FALSE result for each key queried:

Haro

? HasKeysXT(aHash, ["name", "none", "age"])
#--> [ TRUE, FALSE, TRUE ]

illustration

HasPath() is designed for deeply nested structures, allowing you to validate the entire path to a value:

Haro

aDeepHash = [
	:name = "TechCorp",
	:departments = [
		:name = "Engineering",
		:teams = [
			:name = "Backend",
			:members = [...]
		]
	]
]

if HasPath(aDeepHash, ["departments", "teams", "members"])
	# Safe to access the nested value
ok

illustration

The Defensive Approach

For maximum safety, Softanza also offers the stzHashList object, which provides built-in protections against duplicate keys and enforces data integrity:

Haro

o1 = new stzHashList([
	["name", "john"],
	["type", "person"]
])

if NOT o1.HasKey(:job)
	o1.Add(:job = "programmer")
ok

illustration

These functions are now deeply integrated throughout the Softanza codebase, making it more robust, maintainable, and predictable when working with hashlists and nested data structures.

Citer

Mansour Ayouni. « Safe Access to Haro Hashlists: How Softanza Solves a Common Problem ». Softanza narrations, 2025. https://mayouni.github.io/stzsite/fr/narrations/safe-access-to-ring-hashlists-using-haskey.html

Non exécuté : son code ne se charge pas tel qu'il est écrit. L'article est publié tel qu'il est écrit ; ses blocs sont des illustrations. Le code des articles est du code Haro. Là où un article a été écrit avant que la langue prenne son nom actuel, le nom a été changé et rien d'autre. Genre, domaine et série lus dans le nom du fichier, année tirée du premier commit : dérivés, jusqu'à ce que l'article porte son propre en-tête. Le fichier sur GitHub(s'ouvre dans un nouvel onglet)