decimal

Module nustd.decimal.

Nu surface for Python's decimal module - the Decimal type.

Mirrors decimal 1-1 for the value type: Decimal is a Form backed by decimal.Decimal, so arithmetic stays exact. decimal's module-level helpers and contexts (getcontext, localcontext, ROUND_* ...) are out of scope, so there are just two layers: forms (the class) and interactions (the constructor and method atoms; arithmetic and comparison use the core atoms). Import it like the stdlib:

from nustd.decimal import Decimal    # Decimal.of("0.1") + Decimal.of("0.2")

ScalarQuery

Decimal

decimal.Decimal as a Form - exact, arbitrary-precision arithmetic.

Decimal()

Path nustd.decimal.Decimal. Kind ScalarQuery, sort scalar_query, cardinality scalar.

Build one with Decimal.of(...) (string or int, coerced exactly) or Decimal.from_float(...); combine with the arithmetic operators; refine with the method calls. Python does the real Decimal op on the resolved values, so Decimal.of("0.1") + Decimal.of("0.2") is exactly Decimal('0.3').

Methods

Decimal.of(value)

Build a decimal from a string or int, exactly: Decimal(str(value)).

Builds Decimal.

Arguments

Undocumented: example.

Decimal.from_float(value)

From a binary float: Decimal.from_float(f) (carries float error).

Builds Decimal.

Arguments

Undocumented: example.

a + b

Builds Decimal.

Arguments

Undocumented: summary, example.

a - b

Builds Decimal.

Arguments

Undocumented: summary, example.

a * b

Builds Decimal.

Arguments

Undocumented: summary, example.

a / b

Builds Decimal.

Arguments

Undocumented: summary, example.

a // b

Builds Decimal.

Arguments

Undocumented: summary, example.

a % b

Builds Decimal.

Arguments

Undocumented: summary, example.

a ** b

Builds Decimal.

Arguments

Undocumented: summary, example.

-a

Builds Decimal.

Undocumented: summary, example.

abs(a)

Builds Decimal.

Undocumented: summary, example.

+a

Builds Decimal.

Undocumented: summary, example.

.quantize(exp)

Round to the exponent of exp (e.g. Decimal.of("0.01")).

Builds Decimal.

Arguments

Undocumented: example.

.normalize()

A canonical form with trailing zeros removed.

Builds Decimal.

Undocumented: example.

.to_integral_value()

The value rounded to the nearest integer, kept as a Decimal.

Builds Decimal.

Undocumented: example.

.sqrt()

The square root.

Builds Decimal.

Undocumented: example.

.exp()

The exponential, e ** self.

Builds Decimal.

Undocumented: example.

.ln()

The natural logarithm.

Builds Decimal.

Undocumented: example.

.log10()

The base-10 logarithm.

Builds Decimal.

Undocumented: example.

.compare(other)

Decimal('-1') / '0' / '1' for self <, ==, > other.

Builds Decimal.

Arguments

Undocumented: example.

.copy_abs()

The absolute value (context-free, no rounding).

Builds Decimal.

Undocumented: example.

.copy_negate()

The negation (context-free, no rounding).

Builds Decimal.

Undocumented: example.

.adjusted()

The adjusted exponent after shifting out the coefficient's digits.

Builds Int.

Undocumented: example.

.as_integer_ratio()

The exact value as a (numerator, denominator) pair of ints.

Builds Tuple.

Undocumented: example.

.is_finite()

Whether the value is finite (not infinite, not NaN).

Builds Bool.

Undocumented: example.

.is_infinite()

Whether the value is positive or negative infinity.

Builds Bool.

Undocumented: example.

.is_nan()

Whether the value is a NaN (quiet or signaling).

Builds Bool.

Undocumented: example.

.is_zero()

Whether the value is zero (positive or negative).

Builds Bool.

Undocumented: example.

.is_signed()

Whether the sign bit is set (negative, including -0).

Builds Bool.

Undocumented: example.

a > b

Builds Bool.

Arguments

Undocumented: summary, example.

a < b

Builds Bool.

Arguments

Undocumented: summary, example.

a >= b

Builds Bool.

Arguments

Undocumented: summary, example.

a <= b

Builds Bool.

Arguments

Undocumented: summary, example.

.eq(other)

Whether two decimals are equal in value.

Builds Bool.

Arguments

Undocumented: example.

.ne(other)

Whether two decimals differ in value.

Builds Bool.

Arguments

Undocumented: example.

Inherited methods

From nu.lang.forms.Form:

Undocumented: example.