PuduLangLog.Expressions.Values

type: module path: "@root/src/PuduLangLog/Expressions/Values.pudu" fidelity: Active grammar: "[[grammar/pudu]]" depth_score: 0.6 depth_status: MEDIUM tags: [module, expressions] aliases: [PuduLangLog.Expressions.Values]

Purpose

The meaning of values inside expressions: truth, numbers across kinds, equality, order, like patterns, and rendering.

Interface

Signatures

export fn boolean(flag: Bool) -> Option[Log.Value]

export fn number(held: Decimal) -> Option[Log.Value]

export fn text(held: Str) -> Option[Log.Value]

export fn isTrue(held: &Option[Log.Value]) -> Bool

export fn decimalOf(held: &Option[Log.Value]) -> Option[Decimal]

export fn textOf(held: &Option[Log.Value]) -> Option[Str]

export fn itemsOf(held: &Option[Log.Value]) -> Option[Array[Log.Value]]

export fn equal(left: &Log.Value, right: &Log.Value, ignoring: Bool) -> Bool

export fn equals(left: &Option[Log.Value], right: &Option[Log.Value], ignoring: Bool) -> Option[Log.Value]

export fn compare(operator: Str, left: &Option[Log.Value], right: &Option[Log.Value]) -> Option[Log.Value]

export fn like(subject: Str, pattern: Str, ignoring: Bool) -> Bool

export fn render(held: &Log.Value, format: Option[Str]) -> Str

Linkage

• Requires: [[src/PuduLangLog]], [[src/PuduLangLog/Domain/Display]], Std.Decimal, Std.List.
• Consumed by: [[src/PuduLangLog/Expressions/Evaluator]], [[src/PuduLangLog/Expressions/Functions]], [[src/PuduLangLog/Expressions/Template]], and [[src/PuduLangLog/Expressions]].

Algorithm

1. Only the boolean true is true.
2. Integers, floats, and decimals compare as decimals, so 3 = 3.0.
3. number stores a result at the smallest scale that keeps it, so 1 / 4 is 0.25.
4. Equality with an undefined side is undefined; ordering is defined only between numbers.
5. like matches % against any run and _ against one character; doubled wildcards are literal.

Negative Logic (Prohibited Paths)

• Text is never ordered; 'a' < 'b' is undefined.

Edge Cases

• Structures are equal when they hold the same members, in any order.

Depth

DEPTH 0.6 (MEDIUM). Tested by test/PuduLangLog/ExpressionsTest.

Grill Log

• Q: Why normalise the scale of results? A: Division answers 28 places, and a result compared or printed with trailing zeros differs from the literal a user wrote. _Rejected:_ comparing by value only, which still prints 0.2500….

Referenced by

[[CHANGELOG]] · [[src/PuduLangLog/_MOC]] · [[src/PuduLangLog/Expressions]] · [[src/PuduLangLog/Expressions/Evaluator]] · [[src/PuduLangLog/Expressions/Functions]] · [[src/PuduLangLog/Expressions/Template]] · [[subsystems/Expressions]]