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- /**
- * 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]
- */
- import { getBytes } from "./data.js";
- import { assert, assertArgument, assertPrivate } from "./errors.js";
- import { getBigInt, getNumber, fromTwos, mask, toBigInt } from "./maths.js";
- import { defineProperties } from "./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));
- assert(safeOp == null || (val >= -limit && val < limit), "overflow", "NUMERIC_FAULT", {
- operation: safeOp, fault: "overflow", value: val
- });
- if (val > BN_0) {
- val = fromTwos(mask(val, width), width);
- }
- else {
- val = -fromTwos(mask(-val, width), width);
- }
- }
- else {
- const limit = (BN_1 << width);
- 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${value}`;
- }
- let signed = true;
- let width = 128;
- let decimals = 18;
- if (typeof (value) === "string") {
- // Parse the format string
- if (value === "fixed") {
- // defaults...
- }
- else if (value === "ufixed") {
- signed = false;
- }
- else {
- const match = value.match(/^(u?)fixed([0-9]+)x([0-9]+)$/);
- 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;
- }
- 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);
- }
- assertArgument((width % 8) === 0, "invalid FixedNumber width (not byte aligned)", "format.width", width);
- 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.
- */
- export 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) {
- assertPrivate(guard, _guard, "FixedNumber");
- this.#val = value;
- this.#format = format;
- const _value = toString(value, format.decimals);
- 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) {
- 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;
- 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) {
- 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) {
- 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);
- 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) {
- const decimals = (_decimals == null) ? 0 : getNumber(_decimals);
- const format = getFormat(_format);
- let value = getBigInt(_value, "value");
- const delta = decimals - format.decimals;
- if (delta > 0) {
- const tens = getTens(delta);
- 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]*)$/);
- assertArgument(match && (match[2].length + match[3].length) > 0, "invalid FixedNumber string value", "value", _value);
- const format = getFormat(_format);
- let whole = (match[2] || "0"), decimal = (match[3] || "");
- // Pad out the decimals
- while (decimal.length < format.decimals) {
- decimal += Zeros;
- }
- // Check precision is safe
- assert(decimal.substring(format.decimals).match(/^0*$/), "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 = toBigInt(getBytes(_value, "value"));
- const format = getFormat(_format);
- if (format.signed) {
- value = fromTwos(value, format.width);
- }
- checkValue(value, format, "fromBytes");
- return new FixedNumber(_guard, value, format);
- }
- }
- //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
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