Decimal

Fixed-precision decimal values for financial and high-precision computations

A Decimal in Internet Object represents fixed-precision decimal values designed for applications that require exact numeric calculations, especially financial computations where floating-point precision issues could lead to significant errors. Decimal is a scalar primitive that stores exact numeric values with a defined precision and scale.

Unlike standard floating-point numbers (which may suffer from approximation issues), Decimal values maintain exact precision throughout arithmetic operations, ensuring accurate and predictable results.

Syntax

A Decimal value is expressed as a number with the m suffix:

decimal = decimalValue | scientificDecimal

decimalValue = ["-" | "+"] digit+ ["." digit+] "m"
scientificDecimal = decimalValue ("e" | "E") ["-" | "+"] digit+

digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"

Structural Characters

Symbol

Name

Unicode

Description

m

Decimal Suffix

U+006D

Identifies value as Decimal

0-9

Digits

Multiple

Standard decimal digits

.

Decimal Point

U+002E

Separates integer and fraction

-

Minus Sign

U+002D

Indicates negative numbers

e/E

Exponent

Multiple

Scientific notation exponent

Valid Forms

Basic Decimal Values

123.45m              # Fractional decimal
123m                 # Integer decimal
0.001m               # Leading zeros
-789.01m             # Negative decimal

Scientific Notation

1.23e2m              # Equivalent to 123m
1.23e-2m             # Equivalent to 0.0123m
5e3m                 # Equivalent to 5000m

Optional Behaviors

Fixed-Precision Arithmetic

Decimal values maintain their precision throughout operations:

0.1m + 0.2m          # 0.3m (exact representation)
# Compare with floating-point: 0.1 + 0.2 ≈ 0.30000000000000004

Precision and Scale

Each Decimal value is defined by:

Precision: Total number of significant digits
Scale: Number of digits after the decimal point

123.45m              # Precision: 5, Scale: 2
0.000123m            # Precision: 6, Scale: 6

Empty Representation

Zero as a decimal:

0m                   # Zero decimal
0.0m                 # Zero with scale

Invalid Forms

123.45               # ❌ Missing 'm' suffix (should be 123.45m)
123.45mm             # ❌ Multiple suffixes not allowed (should be 123.45m)
m123.45              # ❌ Suffix must be at the end (should be 123.45m)
.45m                 # ❌ Must have leading digit (should be 0.45m)
123.m                # ❌ Must have trailing digit if decimal point used (should be 123.0m or 123m)

Preservation of Structure

Internet Object preserves:

Exact decimal precision and scale
The chosen representation form (standard vs scientific notation)
Syntactic fidelity (as written, except that an explicit plus sign is not preserved)

However, it does not interpret:

Rounding behavior for operations
Domain-specific precision requirements
Currency or unit semantics

Such semantics are the responsibility of the schema layer, validators, or application logic.