532 lines
20 KiB
JavaScript
532 lines
20 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
exports.FixedNumber = void 0;
|
|
/**
|
|
* The **FixedNumber** class permits using values with decimal places,
|
|
* using fixed-pont math.
|
|
*
|
|
* Fixed-point math is still based on integers under-the-hood, but uses an
|
|
* internal offset to store fractional components below, and each operation
|
|
* corrects for this after each operation.
|
|
*
|
|
* @_section: api/utils/fixed-point-math:Fixed-Point Maths [about-fixed-point-math]
|
|
*/
|
|
const data_js_1 = require("./data.js");
|
|
const errors_js_1 = require("./errors.js");
|
|
const maths_js_1 = require("./maths.js");
|
|
const properties_js_1 = require("./properties.js");
|
|
const BN_N1 = BigInt(-1);
|
|
const BN_0 = BigInt(0);
|
|
const BN_1 = BigInt(1);
|
|
const BN_5 = BigInt(5);
|
|
const _guard = {};
|
|
// Constant to pull zeros from for multipliers
|
|
let Zeros = "0000";
|
|
while (Zeros.length < 80) {
|
|
Zeros += Zeros;
|
|
}
|
|
// Returns a string "1" followed by decimal "0"s
|
|
function getTens(decimals) {
|
|
let result = Zeros;
|
|
while (result.length < decimals) {
|
|
result += result;
|
|
}
|
|
return BigInt("1" + result.substring(0, decimals));
|
|
}
|
|
function checkValue(val, format, safeOp) {
|
|
const width = BigInt(format.width);
|
|
if (format.signed) {
|
|
const limit = (BN_1 << (width - BN_1));
|
|
(0, errors_js_1.assert)(safeOp == null || (val >= -limit && val < limit), "overflow", "NUMERIC_FAULT", {
|
|
operation: safeOp, fault: "overflow", value: val
|
|
});
|
|
if (val > BN_0) {
|
|
val = (0, maths_js_1.fromTwos)((0, maths_js_1.mask)(val, width), width);
|
|
}
|
|
else {
|
|
val = -(0, maths_js_1.fromTwos)((0, maths_js_1.mask)(-val, width), width);
|
|
}
|
|
}
|
|
else {
|
|
const limit = (BN_1 << width);
|
|
(0, errors_js_1.assert)(safeOp == null || (val >= 0 && val < limit), "overflow", "NUMERIC_FAULT", {
|
|
operation: safeOp, fault: "overflow", value: val
|
|
});
|
|
val = (((val % limit) + limit) % limit) & (limit - BN_1);
|
|
}
|
|
return val;
|
|
}
|
|
function getFormat(value) {
|
|
if (typeof (value) === "number") {
|
|
value = `fixed128x${value}`;
|
|
}
|
|
let signed = true;
|
|
let width = 128;
|
|
let decimals = 18;
|
|
if (typeof (value) === "string") {
|
|
// Parse the format string
|
|
if (value === "fixed") {
|
|
// defaults...
|
|
}
|
|
else if (value === "ufixed") {
|
|
signed = false;
|
|
}
|
|
else {
|
|
const match = value.match(/^(u?)fixed([0-9]+)x([0-9]+)$/);
|
|
(0, errors_js_1.assertArgument)(match, "invalid fixed format", "format", value);
|
|
signed = (match[1] !== "u");
|
|
width = parseInt(match[2]);
|
|
decimals = parseInt(match[3]);
|
|
}
|
|
}
|
|
else if (value) {
|
|
// Extract the values from the object
|
|
const v = value;
|
|
const check = (key, type, defaultValue) => {
|
|
if (v[key] == null) {
|
|
return defaultValue;
|
|
}
|
|
(0, errors_js_1.assertArgument)(typeof (v[key]) === type, "invalid fixed format (" + key + " not " + type + ")", "format." + key, v[key]);
|
|
return v[key];
|
|
};
|
|
signed = check("signed", "boolean", signed);
|
|
width = check("width", "number", width);
|
|
decimals = check("decimals", "number", decimals);
|
|
}
|
|
(0, errors_js_1.assertArgument)((width % 8) === 0, "invalid FixedNumber width (not byte aligned)", "format.width", width);
|
|
(0, errors_js_1.assertArgument)(decimals <= 80, "invalid FixedNumber decimals (too large)", "format.decimals", decimals);
|
|
const name = (signed ? "" : "u") + "fixed" + String(width) + "x" + String(decimals);
|
|
return { signed, width, decimals, name };
|
|
}
|
|
function toString(val, decimals) {
|
|
let negative = "";
|
|
if (val < BN_0) {
|
|
negative = "-";
|
|
val *= BN_N1;
|
|
}
|
|
let str = val.toString();
|
|
// No decimal point for whole values
|
|
if (decimals === 0) {
|
|
return (negative + str);
|
|
}
|
|
// Pad out to the whole component (including a whole digit)
|
|
while (str.length <= decimals) {
|
|
str = Zeros + str;
|
|
}
|
|
// Insert the decimal point
|
|
const index = str.length - decimals;
|
|
str = str.substring(0, index) + "." + str.substring(index);
|
|
// Trim the whole component (leaving at least one 0)
|
|
while (str[0] === "0" && str[1] !== ".") {
|
|
str = str.substring(1);
|
|
}
|
|
// Trim the decimal component (leaving at least one 0)
|
|
while (str[str.length - 1] === "0" && str[str.length - 2] !== ".") {
|
|
str = str.substring(0, str.length - 1);
|
|
}
|
|
return (negative + str);
|
|
}
|
|
/**
|
|
* A FixedNumber represents a value over its [[FixedFormat]]
|
|
* arithmetic field.
|
|
*
|
|
* A FixedNumber can be used to perform math, losslessly, on
|
|
* values which have decmial places.
|
|
*
|
|
* A FixedNumber has a fixed bit-width to store values in, and stores all
|
|
* values internally by multiplying the value by 10 raised to the power of
|
|
* %%decimals%%.
|
|
*
|
|
* If operations are performed that cause a value to grow too high (close to
|
|
* positive infinity) or too low (close to negative infinity), the value
|
|
* is said to //overflow//.
|
|
*
|
|
* For example, an 8-bit signed value, with 0 decimals may only be within
|
|
* the range ``-128`` to ``127``; so ``-128 - 1`` will overflow and become
|
|
* ``127``. Likewise, ``127 + 1`` will overflow and become ``-127``.
|
|
*
|
|
* Many operation have a normal and //unsafe// variant. The normal variant
|
|
* will throw a [[NumericFaultError]] on any overflow, while the //unsafe//
|
|
* variant will silently allow overflow, corrupting its value value.
|
|
*
|
|
* If operations are performed that cause a value to become too small
|
|
* (close to zero), the value loses precison and is said to //underflow//.
|
|
*
|
|
* For example, an value with 1 decimal place may store a number as small
|
|
* as ``0.1``, but the value of ``0.1 / 2`` is ``0.05``, which cannot fit
|
|
* into 1 decimal place, so underflow occurs which means precision is lost
|
|
* and the value becomes ``0``.
|
|
*
|
|
* Some operations have a normal and //signalling// variant. The normal
|
|
* variant will silently ignore underflow, while the //signalling// variant
|
|
* will thow a [[NumericFaultError]] on underflow.
|
|
*/
|
|
class FixedNumber {
|
|
/**
|
|
* The specific fixed-point arithmetic field for this value.
|
|
*/
|
|
format;
|
|
#format;
|
|
// The actual value (accounting for decimals)
|
|
#val;
|
|
// A base-10 value to multiple values by to maintain the magnitude
|
|
#tens;
|
|
/**
|
|
* This is a property so console.log shows a human-meaningful value.
|
|
*
|
|
* @private
|
|
*/
|
|
_value;
|
|
// Use this when changing this file to get some typing info,
|
|
// but then switch to any to mask the internal type
|
|
//constructor(guard: any, value: bigint, format: _FixedFormat) {
|
|
/**
|
|
* @private
|
|
*/
|
|
constructor(guard, value, format) {
|
|
(0, errors_js_1.assertPrivate)(guard, _guard, "FixedNumber");
|
|
this.#val = value;
|
|
this.#format = format;
|
|
const _value = toString(value, format.decimals);
|
|
(0, properties_js_1.defineProperties)(this, { format: format.name, _value });
|
|
this.#tens = getTens(format.decimals);
|
|
}
|
|
/**
|
|
* If true, negative values are permitted, otherwise only
|
|
* positive values and zero are allowed.
|
|
*/
|
|
get signed() { return this.#format.signed; }
|
|
/**
|
|
* The number of bits available to store the value.
|
|
*/
|
|
get width() { return this.#format.width; }
|
|
/**
|
|
* The number of decimal places in the fixed-point arithment field.
|
|
*/
|
|
get decimals() { return this.#format.decimals; }
|
|
/**
|
|
* The value as an integer, based on the smallest unit the
|
|
* [[decimals]] allow.
|
|
*/
|
|
get value() { return this.#val; }
|
|
#checkFormat(other) {
|
|
(0, errors_js_1.assertArgument)(this.format === other.format, "incompatible format; use fixedNumber.toFormat", "other", other);
|
|
}
|
|
#checkValue(val, safeOp) {
|
|
/*
|
|
const width = BigInt(this.width);
|
|
if (this.signed) {
|
|
const limit = (BN_1 << (width - BN_1));
|
|
assert(safeOp == null || (val >= -limit && val < limit), "overflow", "NUMERIC_FAULT", {
|
|
operation: <string>safeOp, fault: "overflow", value: val
|
|
});
|
|
|
|
if (val > BN_0) {
|
|
val = fromTwos(mask(val, width), width);
|
|
} else {
|
|
val = -fromTwos(mask(-val, width), width);
|
|
}
|
|
|
|
} else {
|
|
const masked = mask(val, width);
|
|
assert(safeOp == null || (val >= 0 && val === masked), "overflow", "NUMERIC_FAULT", {
|
|
operation: <string>safeOp, fault: "overflow", value: val
|
|
});
|
|
val = masked;
|
|
}
|
|
*/
|
|
val = checkValue(val, this.#format, safeOp);
|
|
return new FixedNumber(_guard, val, this.#format);
|
|
}
|
|
#add(o, safeOp) {
|
|
this.#checkFormat(o);
|
|
return this.#checkValue(this.#val + o.#val, safeOp);
|
|
}
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% added
|
|
* to %%other%%, ignoring overflow.
|
|
*/
|
|
addUnsafe(other) { return this.#add(other); }
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% added
|
|
* to %%other%%. A [[NumericFaultError]] is thrown if overflow
|
|
* occurs.
|
|
*/
|
|
add(other) { return this.#add(other, "add"); }
|
|
#sub(o, safeOp) {
|
|
this.#checkFormat(o);
|
|
return this.#checkValue(this.#val - o.#val, safeOp);
|
|
}
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%other%% subtracted
|
|
* from %%this%%, ignoring overflow.
|
|
*/
|
|
subUnsafe(other) { return this.#sub(other); }
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%other%% subtracted
|
|
* from %%this%%. A [[NumericFaultError]] is thrown if overflow
|
|
* occurs.
|
|
*/
|
|
sub(other) { return this.#sub(other, "sub"); }
|
|
#mul(o, safeOp) {
|
|
this.#checkFormat(o);
|
|
return this.#checkValue((this.#val * o.#val) / this.#tens, safeOp);
|
|
}
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% multiplied
|
|
* by %%other%%, ignoring overflow and underflow (precision loss).
|
|
*/
|
|
mulUnsafe(other) { return this.#mul(other); }
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% multiplied
|
|
* by %%other%%. A [[NumericFaultError]] is thrown if overflow
|
|
* occurs.
|
|
*/
|
|
mul(other) { return this.#mul(other, "mul"); }
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% multiplied
|
|
* by %%other%%. A [[NumericFaultError]] is thrown if overflow
|
|
* occurs or if underflow (precision loss) occurs.
|
|
*/
|
|
mulSignal(other) {
|
|
this.#checkFormat(other);
|
|
const value = this.#val * other.#val;
|
|
(0, errors_js_1.assert)((value % this.#tens) === BN_0, "precision lost during signalling mul", "NUMERIC_FAULT", {
|
|
operation: "mulSignal", fault: "underflow", value: this
|
|
});
|
|
return this.#checkValue(value / this.#tens, "mulSignal");
|
|
}
|
|
#div(o, safeOp) {
|
|
(0, errors_js_1.assert)(o.#val !== BN_0, "division by zero", "NUMERIC_FAULT", {
|
|
operation: "div", fault: "divide-by-zero", value: this
|
|
});
|
|
this.#checkFormat(o);
|
|
return this.#checkValue((this.#val * this.#tens) / o.#val, safeOp);
|
|
}
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% divided
|
|
* by %%other%%, ignoring underflow (precision loss). A
|
|
* [[NumericFaultError]] is thrown if overflow occurs.
|
|
*/
|
|
divUnsafe(other) { return this.#div(other); }
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% divided
|
|
* by %%other%%, ignoring underflow (precision loss). A
|
|
* [[NumericFaultError]] is thrown if overflow occurs.
|
|
*/
|
|
div(other) { return this.#div(other, "div"); }
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the result of %%this%% divided
|
|
* by %%other%%. A [[NumericFaultError]] is thrown if underflow
|
|
* (precision loss) occurs.
|
|
*/
|
|
divSignal(other) {
|
|
(0, errors_js_1.assert)(other.#val !== BN_0, "division by zero", "NUMERIC_FAULT", {
|
|
operation: "div", fault: "divide-by-zero", value: this
|
|
});
|
|
this.#checkFormat(other);
|
|
const value = (this.#val * this.#tens);
|
|
(0, errors_js_1.assert)((value % other.#val) === BN_0, "precision lost during signalling div", "NUMERIC_FAULT", {
|
|
operation: "divSignal", fault: "underflow", value: this
|
|
});
|
|
return this.#checkValue(value / other.#val, "divSignal");
|
|
}
|
|
/**
|
|
* Returns a comparison result between %%this%% and %%other%%.
|
|
*
|
|
* This is suitable for use in sorting, where ``-1`` implies %%this%%
|
|
* is smaller, ``1`` implies %%this%% is larger and ``0`` implies
|
|
* both are equal.
|
|
*/
|
|
cmp(other) {
|
|
let a = this.value, b = other.value;
|
|
// Coerce a and b to the same magnitude
|
|
const delta = this.decimals - other.decimals;
|
|
if (delta > 0) {
|
|
b *= getTens(delta);
|
|
}
|
|
else if (delta < 0) {
|
|
a *= getTens(-delta);
|
|
}
|
|
// Comnpare
|
|
if (a < b) {
|
|
return -1;
|
|
}
|
|
if (a > b) {
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
/**
|
|
* Returns true if %%other%% is equal to %%this%%.
|
|
*/
|
|
eq(other) { return this.cmp(other) === 0; }
|
|
/**
|
|
* Returns true if %%other%% is less than to %%this%%.
|
|
*/
|
|
lt(other) { return this.cmp(other) < 0; }
|
|
/**
|
|
* Returns true if %%other%% is less than or equal to %%this%%.
|
|
*/
|
|
lte(other) { return this.cmp(other) <= 0; }
|
|
/**
|
|
* Returns true if %%other%% is greater than to %%this%%.
|
|
*/
|
|
gt(other) { return this.cmp(other) > 0; }
|
|
/**
|
|
* Returns true if %%other%% is greater than or equal to %%this%%.
|
|
*/
|
|
gte(other) { return this.cmp(other) >= 0; }
|
|
/**
|
|
* Returns a new [[FixedNumber]] which is the largest **integer**
|
|
* that is less than or equal to %%this%%.
|
|
*
|
|
* The decimal component of the result will always be ``0``.
|
|
*/
|
|
floor() {
|
|
let val = this.#val;
|
|
if (this.#val < BN_0) {
|
|
val -= this.#tens - BN_1;
|
|
}
|
|
val = (this.#val / this.#tens) * this.#tens;
|
|
return this.#checkValue(val, "floor");
|
|
}
|
|
/**
|
|
* Returns a new [[FixedNumber]] which is the smallest **integer**
|
|
* that is greater than or equal to %%this%%.
|
|
*
|
|
* The decimal component of the result will always be ``0``.
|
|
*/
|
|
ceiling() {
|
|
let val = this.#val;
|
|
if (this.#val > BN_0) {
|
|
val += this.#tens - BN_1;
|
|
}
|
|
val = (this.#val / this.#tens) * this.#tens;
|
|
return this.#checkValue(val, "ceiling");
|
|
}
|
|
/**
|
|
* Returns a new [[FixedNumber]] with the decimal component
|
|
* rounded up on ties at %%decimals%% places.
|
|
*/
|
|
round(decimals) {
|
|
if (decimals == null) {
|
|
decimals = 0;
|
|
}
|
|
// Not enough precision to not already be rounded
|
|
if (decimals >= this.decimals) {
|
|
return this;
|
|
}
|
|
const delta = this.decimals - decimals;
|
|
const bump = BN_5 * getTens(delta - 1);
|
|
let value = this.value + bump;
|
|
const tens = getTens(delta);
|
|
value = (value / tens) * tens;
|
|
checkValue(value, this.#format, "round");
|
|
return new FixedNumber(_guard, value, this.#format);
|
|
}
|
|
/**
|
|
* Returns true if %%this%% is equal to ``0``.
|
|
*/
|
|
isZero() { return (this.#val === BN_0); }
|
|
/**
|
|
* Returns true if %%this%% is less than ``0``.
|
|
*/
|
|
isNegative() { return (this.#val < BN_0); }
|
|
/**
|
|
* Returns the string representation of %%this%%.
|
|
*/
|
|
toString() { return this._value; }
|
|
/**
|
|
* Returns a float approximation.
|
|
*
|
|
* Due to IEEE 754 precission (or lack thereof), this function
|
|
* can only return an approximation and most values will contain
|
|
* rounding errors.
|
|
*/
|
|
toUnsafeFloat() { return parseFloat(this.toString()); }
|
|
/**
|
|
* Return a new [[FixedNumber]] with the same value but has had
|
|
* its field set to %%format%%.
|
|
*
|
|
* This will throw if the value cannot fit into %%format%%.
|
|
*/
|
|
toFormat(format) {
|
|
return FixedNumber.fromString(this.toString(), format);
|
|
}
|
|
/**
|
|
* Creates a new [[FixedNumber]] for %%value%% divided by
|
|
* %%decimal%% places with %%format%%.
|
|
*
|
|
* This will throw a [[NumericFaultError]] if %%value%% (once adjusted
|
|
* for %%decimals%%) cannot fit in %%format%%, either due to overflow
|
|
* or underflow (precision loss).
|
|
*/
|
|
static fromValue(_value, decimals, _format) {
|
|
if (decimals == null) {
|
|
decimals = 0;
|
|
}
|
|
const format = getFormat(_format);
|
|
let value = (0, maths_js_1.getBigInt)(_value, "value");
|
|
const delta = decimals - format.decimals;
|
|
if (delta > 0) {
|
|
const tens = getTens(delta);
|
|
(0, errors_js_1.assert)((value % tens) === BN_0, "value loses precision for format", "NUMERIC_FAULT", {
|
|
operation: "fromValue", fault: "underflow", value: _value
|
|
});
|
|
value /= tens;
|
|
}
|
|
else if (delta < 0) {
|
|
value *= getTens(-delta);
|
|
}
|
|
checkValue(value, format, "fromValue");
|
|
return new FixedNumber(_guard, value, format);
|
|
}
|
|
/**
|
|
* Creates a new [[FixedNumber]] for %%value%% with %%format%%.
|
|
*
|
|
* This will throw a [[NumericFaultError]] if %%value%% cannot fit
|
|
* in %%format%%, either due to overflow or underflow (precision loss).
|
|
*/
|
|
static fromString(_value, _format) {
|
|
const match = _value.match(/^(-?)([0-9]*)\.?([0-9]*)$/);
|
|
(0, errors_js_1.assertArgument)(match && (match[2].length + match[3].length) > 0, "invalid FixedNumber string value", "value", _value);
|
|
const format = getFormat(_format);
|
|
let whole = (match[2] || "0"), decimal = (match[3] || "");
|
|
// Pad out the decimals
|
|
while (decimal.length < format.decimals) {
|
|
decimal += Zeros;
|
|
}
|
|
// Check precision is safe
|
|
(0, errors_js_1.assert)(decimal.substring(format.decimals).match(/^0*$/), "too many decimals for format", "NUMERIC_FAULT", {
|
|
operation: "fromString", fault: "underflow", value: _value
|
|
});
|
|
// Remove extra padding
|
|
decimal = decimal.substring(0, format.decimals);
|
|
const value = BigInt(match[1] + whole + decimal);
|
|
checkValue(value, format, "fromString");
|
|
return new FixedNumber(_guard, value, format);
|
|
}
|
|
/**
|
|
* Creates a new [[FixedNumber]] with the big-endian representation
|
|
* %%value%% with %%format%%.
|
|
*
|
|
* This will throw a [[NumericFaultError]] if %%value%% cannot fit
|
|
* in %%format%% due to overflow.
|
|
*/
|
|
static fromBytes(_value, _format) {
|
|
let value = (0, maths_js_1.toBigInt)((0, data_js_1.getBytes)(_value, "value"));
|
|
const format = getFormat(_format);
|
|
if (format.signed) {
|
|
value = (0, maths_js_1.fromTwos)(value, format.width);
|
|
}
|
|
checkValue(value, format, "fromBytes");
|
|
return new FixedNumber(_guard, value, format);
|
|
}
|
|
}
|
|
exports.FixedNumber = FixedNumber;
|
|
//const f1 = FixedNumber.fromString("12.56", "fixed16x2");
|
|
//const f2 = FixedNumber.fromString("0.3", "fixed16x2");
|
|
//console.log(f1.divSignal(f2));
|
|
//const BUMP = FixedNumber.from("0.5");
|
|
//# sourceMappingURL=fixednumber.js.map
|