hyf

commit a553585aca98e1ba0a3ce4fbc62ded353d7d6ea3
parent c3bc4fb27054eb6a7aaa7e75ab6285f47d44a6c5
Author: triesap <tyson@radroots.org>
Date:   Mon, 21 Sep 2026 12:56:35 +0000

core: add price and currency types

Diffstat:
A
src/hyf_core/domain/price.mojo
 | 
67
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
tests/test_domain.mojo
 | 
27
+++++++++++++++++++++++++++

2 files changed, 94 insertions(+), 0 deletions(-)
diff --git a/src/hyf_core/domain/price.mojo b/src/hyf_core/domain/price.mojo
@@ -0,0 +1,67 @@
+from std.collections import Optional
+
+
+@fieldwise_init
+struct Price(Copyable, Movable):
+    var state: String
+    var amount: Int
+    var scale: Int
+    var currency: String
+    var basis: String
+
+
+def known_price(
+    amount: Int, scale: Int, currency: String, basis: String
+) raises -> Price:
+    if scale < 0 or scale > 9:
+        raise Error("price scale must be between 0 and 9")
+    if currency.strip() == "":
+        raise Error("known price requires a currency")
+    if (
+        basis != "per_unit"
+        and basis != "per_pack"
+        and basis != "per_order"
+    ):
+        raise Error("price basis must be per_unit, per_pack or per_order")
+    if amount < 0:
+        raise Error("price amount must be non-negative")
+    return Price(
+        state="known",
+        amount=amount,
+        scale=scale,
+        currency=String(currency),
+        basis=String(basis),
+    )
+
+
+def unknown_price() -> Price:
+    return Price(
+        state="unknown", amount=0, scale=0, currency="", basis="unknown"
+    )
+
+
+def price_is_known(price: Price) -> Bool:
+    return price.state == "known"
+
+
+def price_compare(left: Price, right: Price) raises -> Int:
+    if not price_is_known(left) or not price_is_known(right):
+        raise Error("cannot compare unknown prices")
+    if left.currency != right.currency:
+        raise Error(
+            "cannot compare prices in different currencies without conversion"
+        )
+    if left.basis != right.basis:
+        raise Error("cannot compare prices with different bases")
+    var scale = left.scale if left.scale > right.scale else right.scale
+    var left_value = left.amount
+    var right_value = right.amount
+    for _ in range(scale - left.scale):
+        left_value *= 10
+    for _ in range(scale - right.scale):
+        right_value *= 10
+    if left_value < right_value:
+        return -1
+    if left_value > right_value:
+        return 1
+    return 0
diff --git a/tests/test_domain.mojo b/tests/test_domain.mojo
@@ -197,3 +197,30 @@ def test_normalization_preserves_approximation() raises:
     assert_equal(normalized.unit, "kg")
     var exact = new_quantity(80, 0, "lb", "mass", "exact")
     assert_equal(normalize_quantity_with_rule(exact, rule).qualifier, "exact")
+
+
+from hyf_core.domain.price import (
+    known_price,
+    price_compare,
+    price_is_known,
+    unknown_price,
+)
+
+
+def test_price_unknown_distinct_from_zero_and_no_fx() raises:
+    var unknown = unknown_price()
+    assert_true(not price_is_known(unknown))
+    assert_equal(unknown.amount, 0)
+    var zero = known_price(0, 2, "CAD", "per_unit")
+    assert_true(price_is_known(zero))
+    var five = known_price(500, 2, "CAD", "per_unit")
+    assert_equal(price_compare(five, zero), 1)
+    with assert_raises():
+        _ = price_compare(five, unknown)
+    var usd = known_price(500, 2, "USD", "per_unit")
+    with assert_raises():
+        _ = price_compare(five, usd)
+    with assert_raises():
+        _ = known_price(1, 2, "", "per_unit")
+    with assert_raises():
+        _ = known_price(1, 2, "CAD", "per_kg_approx")