Files
genieacs/lib/common/boolean-expression.ts
T
Zaid Abdulla b0d50b07e7 Fix synthesized expressions being non-minimal
Let's try this again. The implementation of canRaise callback was
overly complicated and was causing the minimizer to ocassionally
get stuck in a local optima.
2022-06-14 11:23:33 -07:00

1235 lines
37 KiB
TypeScript

/**
* Copyright 2013-2020 GenieACS Inc.
*
* This file is part of GenieACS.
*
* GenieACS is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* GenieACS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with GenieACS. If not, see <http://www.gnu.org/licenses/>.
*/
import * as BI from "./bigint";
import { espresso, complement, tautology } from "espresso-iisojs";
import { Expression } from "../types";
import { map } from "./expression-parser";
import { and, evaluateCallback } from "./expression";
const ZERO = BI.BigInt(0);
const ONE = BI.BigInt(1);
const TWO = BI.BigInt(2);
const NEGATIVE_ONE = BI.BigInt(-1);
class Indeterminates {
public declare map: Map<string, number>;
public declare sortedKeys: string[];
public constructor(str?: string) {
this.map = new Map();
if (str) {
this.map.set(str, 1);
this.sortedKeys = [str];
} else {
this.sortedKeys = [];
}
}
public reciprocal(): Indeterminates {
const res = new Indeterminates();
res.sortedKeys = this.sortedKeys;
res.map = new Map();
for (const [k, v] of this.map) res.map.set(k, 0 - v);
return res;
}
public static multiply(
indeterminates1: Indeterminates,
indeterminates2: Indeterminates
): Indeterminates {
const res = new Indeterminates();
res.sortedKeys = indeterminates1.sortedKeys.slice();
res.map = new Map(indeterminates1.map);
for (const [key, val] of indeterminates2.map) {
const v = res.map.get(key);
if (!v) {
res.map.set(key, val);
res.sortedKeys.push(key);
} else {
const v2 = val + v;
if (!v2) {
res.map.delete(key);
res.sortedKeys = res.sortedKeys.filter((s) => s !== key);
} else {
res.map.set(key, v2);
}
}
}
res.sortedKeys.sort((a, b) => {
if (a.length !== b.length) return b.length - a.length;
else if (a > b) return 1;
else if (a < b) return -1;
return 0;
});
return res;
}
public static compare(a: Indeterminates, b: Indeterminates): number {
if (a.sortedKeys.length !== b.sortedKeys.length)
return b.sortedKeys.length - a.sortedKeys.length;
for (let i = 0; i < a.sortedKeys.length; ++i) {
const k1 = a.sortedKeys[i];
const w1 = a.map.get(k1);
const k2 = b.sortedKeys[i];
const w2 = b.map.get(k2);
if (w1 !== w2) return w2 - w1;
if (k1.length > k2.length) return -1;
else if (k1.length < k2.length) return 1;
else if (k1 > k2) return 1;
else if (k1 < k2) return -1;
}
return 0;
}
}
interface Term {
indeterminates: Indeterminates;
coefficientNumerator: BI.bigint;
coefficientDenominator: BI.bigint;
}
function findGcd(a: BI.bigint, b: BI.bigint): BI.bigint {
while (BI.ne(b, ZERO)) {
const t = b;
b = BI.rem(a, b);
a = t;
}
return a;
}
class Polynomial {
public declare terms: Term[];
public constructor(terms: Term[]) {
this.terms = terms;
}
public static simplifyTerms(terms: Term[]): Term[] {
const ts = terms
.slice()
.sort((a: Term, b: Term) =>
Indeterminates.compare(a.indeterminates, b.indeterminates)
);
for (let i = 1; i < ts.length; ++i) {
const t1 = ts[i - 1];
const t2 = ts[i];
if (Indeterminates.compare(t1.indeterminates, t2.indeterminates) === 0) {
const numerator = BI.add(
BI.mul(t1.coefficientNumerator, t2.coefficientDenominator),
BI.mul(t2.coefficientNumerator, t1.coefficientDenominator)
);
const denominator = BI.mul(
t1.coefficientDenominator,
t2.coefficientDenominator
);
const gcd = findGcd(numerator, denominator);
ts[i] = {
indeterminates: t2.indeterminates,
coefficientNumerator: BI.div(numerator, gcd),
coefficientDenominator: BI.div(denominator, gcd),
};
ts[i - 1] = {
indeterminates: t1.indeterminates,
coefficientNumerator: ZERO,
coefficientDenominator: t1.coefficientDenominator,
};
}
}
return ts.filter((v) => BI.ne(v.coefficientNumerator, ZERO));
}
public static fromIndeterminate(indeterminate: Expression): Polynomial {
const indeterminates = new Indeterminates(JSON.stringify(indeterminate));
const terms = [
{
indeterminates: indeterminates,
coefficientNumerator: ONE,
coefficientDenominator: ONE,
},
];
return new Polynomial(terms);
}
public static fromConstant(constant: number): Polynomial {
const [int, frac] = Math.abs(constant).toString(2).split(".", 2);
let numerator = BI.BigInt("0b" + int);
if (constant < 0) numerator = BI.mul(numerator, NEGATIVE_ONE);
let denominator = ONE;
if (frac) {
denominator = BI.exp(TWO, BI.BigInt(frac.length));
numerator = BI.add(
BI.mul(numerator, denominator),
BI.BigInt("0b" + frac)
);
}
const terms = [
{
indeterminates: new Indeterminates(),
coefficientNumerator: numerator,
coefficientDenominator: denominator,
},
];
return new Polynomial(terms);
}
public negation(): Polynomial {
const terms = this.terms.map((t) => ({
indeterminates: t.indeterminates,
coefficientNumerator: BI.mul(t.coefficientNumerator, NEGATIVE_ONE),
coefficientDenominator: t.coefficientDenominator,
}));
return new Polynomial(terms);
}
public reciprocal(): Polynomial {
const terms = this.terms.map((t) => ({
indeterminates: t.indeterminates.reciprocal(),
coefficientNumerator: t.coefficientDenominator,
coefficientDenominator: t.coefficientNumerator,
}));
return new Polynomial(terms);
}
public constant(): Polynomial {
const terms = this.terms.filter((t) => !t.indeterminates.sortedKeys.length);
return new Polynomial(terms);
}
public add(rhs: Polynomial): Polynomial {
return new Polynomial(
Polynomial.simplifyTerms(this.terms.concat(rhs.terms))
);
}
public subtract(rhs: Polynomial): Polynomial {
return this.add(rhs.negation());
}
public multiply(rhs: Polynomial): Polynomial {
const terms: Term[] = [];
for (const t1 of this.terms) {
for (const t2 of rhs.terms) {
const numerator = BI.mul(
t1.coefficientNumerator,
t2.coefficientNumerator
);
const denominator = BI.mul(
t1.coefficientDenominator,
t2.coefficientDenominator
);
const gcd = findGcd(numerator, denominator);
terms.push({
indeterminates: Indeterminates.multiply(
t1.indeterminates,
t2.indeterminates
),
coefficientNumerator: BI.div(numerator, gcd),
coefficientDenominator: BI.div(denominator, gcd),
});
}
}
return new Polynomial(Polynomial.simplifyTerms(terms));
}
public divide(rhs: Polynomial): Polynomial {
return this.multiply(rhs.reciprocal());
}
public toString(): string {
const add: string[] = [];
for (const t of this.terms) {
const coefficient =
BI.toNumber(t.coefficientNumerator) /
BI.toNumber(t.coefficientDenominator);
const mul: string[] = [];
if (t.indeterminates.sortedKeys.length) {
for (const k of t.indeterminates.sortedKeys) {
const w = t.indeterminates.map.get(k);
for (let i = Math.abs(w); i > 0; --i) {
if (w > 0) mul.push(k);
else mul.push(`["/",1,${k}]`);
}
}
if (coefficient !== 1) mul.push(coefficient.toString());
if (mul.length > 1) add.push(`["*",${mul.join(",")}]`);
else add.push(mul["0"]);
} else {
add.push(coefficient.toString());
}
}
if (!add.length) return "0";
else if (add.length === 1) return add[0];
else return `["+",${add.join(",")}]`;
}
}
type Minterm = number[];
abstract class BoolExprSynth {
public abstract true(context: SynthContext): Minterm[];
public abstract false(context: SynthContext): Minterm[];
public abstract null(context: SynthContext): Minterm[];
}
class TrueSynth extends BoolExprSynth {
public true(): Minterm[] {
return [[]];
}
public false(): Minterm[] {
return [];
}
public null(): Minterm[] {
return [];
}
}
class FalseSynth extends BoolExprSynth {
public true(): Minterm[] {
return [];
}
public false(): Minterm[] {
return [[]];
}
public null(): Minterm[] {
return [];
}
}
class NullSynth extends BoolExprSynth {
public true(): Minterm[] {
return [];
}
public false(): Minterm[] {
return [];
}
public null(): Minterm[] {
return [[]];
}
}
class VarSynth extends BoolExprSynth {
private declare exp: Expression;
private declare negate: boolean;
public constructor(exp: Expression) {
super();
this.negate = false;
if (Array.isArray(exp)) {
const op = exp[0];
if (op === "<>") {
exp = exp.slice();
exp[0] = "=";
this.negate = true;
} else if (op === ">=") {
exp = exp.slice();
exp[0] = "<";
this.negate = true;
} else if (op === "<=") {
exp = exp.slice();
exp[0] = ">";
this.negate = true;
} else if (op === "NOT LIKE") {
exp = exp.slice();
exp[0] = "LIKE";
this.negate = true;
}
}
this.exp = exp;
}
public true(context: SynthContext): Minterm[] {
const v = context.getVariable(this.exp);
return [[(v << 2) ^ (this.negate ? 1 : 3)]];
}
public false(context: SynthContext): Minterm[] {
const v = context.getVariable(this.exp);
return [[(v << 2) ^ (this.negate ? 3 : 1)]];
}
public null(context: SynthContext): Minterm[] {
const v = context.getVariable(this.exp);
return [[v << 2, (v << 2) ^ 2]];
}
}
class NotSynth extends BoolExprSynth {
private declare exprSynth: BoolExprSynth;
public constructor(e: BoolExprSynth) {
super();
this.exprSynth = e;
}
public true(context: SynthContext): Minterm[] {
return this.exprSynth.false(context);
}
public false(context: SynthContext): Minterm[] {
return this.exprSynth.true(context);
}
public null(context: SynthContext): Minterm[] {
return this.exprSynth.null(context);
}
}
class IsNullSynth extends BoolExprSynth {
private declare exprSynth: BoolExprSynth;
public constructor(e: BoolExprSynth) {
super();
this.exprSynth = e;
}
public true(context: SynthContext): Minterm[] {
return this.exprSynth.null(context);
}
public false(context: SynthContext): Minterm[] {
return [...this.exprSynth.true(context), ...this.exprSynth.false(context)];
}
public null(): Minterm[] {
return [];
}
}
class OrSynth extends BoolExprSynth {
private declare exprSynths: BoolExprSynth[];
public constructor(...e: BoolExprSynth[]) {
super();
this.exprSynths = e.filter((ee) => !(ee instanceof FalseSynth));
const unpacked: BoolExprSynth[] = [];
this.exprSynths = this.exprSynths.filter((ee) => {
if (ee instanceof OrSynth) {
unpacked.push(...ee.exprSynths);
return false;
}
return true;
});
this.exprSynths.push(...unpacked);
}
public true(context: SynthContext): Minterm[] {
if (this.exprSynths.length === 0) return [];
if (this.exprSynths.length === 1) return this.exprSynths[0].true(context);
if (this.exprSynths.some((e) => e instanceof TrueSynth)) return [[]];
return this.exprSynths.map((e) => e.true(context)).flat();
}
public false(context: SynthContext): Minterm[] {
if (this.exprSynths.length === 0) return [[]];
if (this.exprSynths.length === 1) return this.exprSynths[0].false(context);
if (
this.exprSynths.some(
(e) => e instanceof TrueSynth || e instanceof NullSynth
)
)
return [];
return complement(
this.exprSynths.map((e) => complement(e.false(context))).flat()
);
}
public null(context: SynthContext): Minterm[] {
if (this.exprSynths.length === 0) return [];
if (this.exprSynths.length === 1) return this.exprSynths[0].null(context);
const n = this.exprSynths.map((e) => e.null(context)).flat();
const t = this.exprSynths.map((e) => e.true(context)).flat();
return complement([...complement(n), ...t]);
}
}
class AndSynth extends BoolExprSynth {
private declare exprSynths: BoolExprSynth[];
public constructor(...e: BoolExprSynth[]) {
super();
this.exprSynths = e.filter((ee) => !(ee instanceof TrueSynth));
const unpacked: BoolExprSynth[] = [];
this.exprSynths = this.exprSynths.filter((ee) => {
if (ee instanceof AndSynth) {
unpacked.push(...ee.exprSynths);
return false;
}
return true;
});
this.exprSynths.push(...unpacked);
}
public true(context: SynthContext): Minterm[] {
if (this.exprSynths.length === 0) return [[]];
if (this.exprSynths.length === 1) return this.exprSynths[0].true(context);
if (
this.exprSynths.some(
(e) => e instanceof FalseSynth || e instanceof NullSynth
)
)
return [];
return complement(
this.exprSynths.map((e) => complement(e.true(context))).flat()
);
}
public false(context: SynthContext): Minterm[] {
if (this.exprSynths.length === 0) return [];
if (this.exprSynths.length === 1) return this.exprSynths[0].false(context);
if (this.exprSynths.some((e) => e instanceof FalseSynth)) return [[]];
return this.exprSynths.map((e) => e.false(context)).flat();
}
public null(context: SynthContext): Minterm[] {
if (this.exprSynths.length === 0) return [];
if (this.exprSynths.length === 1) return this.exprSynths[0].null(context);
const n = this.exprSynths.map((e) => e.null(context)).flat();
const f = this.exprSynths.map((e) => e.false(context)).flat();
return complement([...complement(n), ...f]);
}
}
class CaseSynth extends BoolExprSynth {
private declare exprSynths: BoolExprSynth[];
public constructor(e: BoolExprSynth[]) {
super();
this.exprSynths = e;
}
public true(context: SynthContext): Minterm[] {
const minterms: Minterm[] = [];
const cumulative: Minterm[] = [];
for (let i = 0; i < this.exprSynths.length; i += 2) {
const w = this.exprSynths[i].true(context);
const t = this.exprSynths[i + 1].true(context);
minterms.push(
...complement([...cumulative, ...complement(w), ...complement(t)])
);
if (i < this.exprSynths.length - 2) {
cumulative.push(
...complement([
...this.exprSynths[i].false(context),
...this.exprSynths[i].null(context),
])
);
}
}
return minterms;
}
public false(context: SynthContext): Minterm[] {
const minterms: Minterm[] = [];
const cumulative: Minterm[] = [];
for (let i = 0; i < this.exprSynths.length; i += 2) {
const w = this.exprSynths[i].true(context);
const t = this.exprSynths[i + 1].false(context);
minterms.push(
...complement([...cumulative, ...complement(w), ...complement(t)])
);
if (i < this.exprSynths.length - 2) {
cumulative.push(
...complement([
...this.exprSynths[i].false(context),
...this.exprSynths[i].null(context),
])
);
}
}
return minterms;
}
public null(context: SynthContext): Minterm[] {
const minterms: Minterm[] = [];
const cumulative: Minterm[] = [];
for (let i = 0; i < this.exprSynths.length; i += 2) {
const w = this.exprSynths[i].true(context);
const t = this.exprSynths[i + 1].null(context);
minterms.push(
...complement([...cumulative, ...complement(w), ...complement(t)])
);
cumulative.push(
...complement([
...this.exprSynths[i].false(context),
...this.exprSynths[i].null(context),
])
);
}
minterms.push(...complement([...cumulative]));
return minterms;
}
}
const ADDITIVE_IDENTITY = Polynomial.fromConstant(0);
const MULTIPLICATIVE_IDENTITY = Polynomial.fromConstant(1);
const SWAPPED_OPS = {
"=": "=",
"<>": "<>",
">": "<",
">=": "<=",
"<": ">",
"<=": ">=",
};
function normalizeCallback(exp: Expression): Expression {
if (!Array.isArray(exp)) return exp;
const op = exp[0];
if (op === "FUNC" && exp[1] === "COALESCE") {
const res: Expression[] = ["CASE"];
for (let i = 2; i < exp.length; ++i)
res.push(normalizeCallback(["IS NOT NULL", exp[i]]), exp[i]);
return normalizeCallback(res);
}
if (op === "CASE") {
const res = [] as [Expression, Expression][];
for (let i = 1; i < exp.length; i += 2) {
let w = exp[i];
if (w instanceof Polynomial) w = JSON.parse(w.toString());
if (!Array.isArray(w) && !w) continue;
const t = exp[i + 1];
if (!Array.isArray(t) || t[0] !== "CASE") {
res.push([w, t]);
continue;
}
for (let j = 1; j < t.length; j += 2) res.push([and(w, t[j]), t[j + 1]]);
res.push([w, null]);
if (!Array.isArray(w) && w) break;
}
while (res[res.length - 1][1] == null) res.pop();
return ["CASE", ...res.flat()];
}
const permutations: Map<number, [Expression, Expression][]> = new Map();
for (const [i, e] of exp.entries()) {
if (!Array.isArray(e)) continue;
if (e[0] !== "CASE") continue;
const perms: [Expression, Expression][] = [];
for (let j = 1; j < e.length; j += 2) perms.push([e[j], e[j + 1]]);
permutations.set(i, perms);
}
if (permutations.size) {
let res: [Expression, Expression][] = [[true, exp]];
for (const [i, perms] of permutations) {
const res2: [Expression, Expression][] = [];
for (const [w, t] of perms) {
res2.push(
...res.map((r) => {
const e = (r[1] as Expression[]).slice();
e[i] = t;
return [and(w, r[0]), e] as [Expression, Expression];
})
);
}
res = res2;
}
for (const r of res) r[1] = normalizeCallback(r[1]);
if (res[0][0] === true) return res[0][1];
while (res[res.length - 1][1] == null) res.pop();
return ["CASE", ...res.flat()];
}
function toPolynomial(e: Expression): Polynomial {
if (e == null) return null;
if (e instanceof Polynomial) return e;
if (typeof e === "number") return Polynomial.fromConstant(e);
if (typeof e === "string")
return Polynomial.fromConstant(parseFloat(e) || 0);
if (typeof e === "boolean") return Polynomial.fromConstant(+e);
return Polynomial.fromIndeterminate(e);
}
if (op === "+") {
const args: Polynomial[] = [];
for (let i = 1; i < exp.length; ++i) {
const p = toPolynomial(exp[i]);
if (p == null) return null;
args.push(p);
}
return args.reduce(
(previousValue, currentValue) => previousValue.add(currentValue),
ADDITIVE_IDENTITY
) as unknown as Expression;
} else if (op === "*") {
const args: Polynomial[] = [];
for (let i = 1; i < exp.length; ++i) {
const p = toPolynomial(exp[i]);
if (p == null) return null;
args.push(p);
}
return args.reduce(
(previousValue, currentValue) => previousValue.multiply(currentValue),
MULTIPLICATIVE_IDENTITY
) as unknown as Expression;
} else if (op === "-") {
const args: Polynomial[] = [];
for (let i = 1; i < exp.length; ++i) {
const p = toPolynomial(exp[i]);
if (p == null) return null;
args.push(p);
}
return args.reduce((previousValue, currentValue) =>
previousValue.subtract(currentValue)
) as unknown as Expression;
} else if (op === "/") {
const args: Polynomial[] = [];
for (let i = 1; i < exp.length; ++i) {
const p = toPolynomial(exp[i]);
if (p == null) return null;
args.push(p);
}
return args.reduce((previousValue, currentValue) =>
previousValue.divide(currentValue)
) as unknown as Expression;
} else if (["=", "<>", ">", ">=", "<", "<="].includes(op)) {
if (exp[1] == null || exp[2] == null) return null;
let lhs: Polynomial, rhs: Polynomial;
if (exp[1] instanceof Polynomial) lhs = exp[1];
else if (typeof exp[1] === "number") lhs = Polynomial.fromConstant(exp[1]);
if (exp[2] instanceof Polynomial) rhs = exp[2];
else if (typeof exp[2] === "number") rhs = Polynomial.fromConstant(exp[2]);
if (lhs || rhs) {
if (!lhs) lhs = Polynomial.fromIndeterminate(exp[1]);
if (!rhs) rhs = Polynomial.fromIndeterminate(exp[2]);
lhs = lhs.subtract(rhs);
rhs = lhs.constant().negation();
lhs = lhs.add(rhs);
if (!lhs.terms.length) {
exp = [op, JSON.parse(lhs.toString()), JSON.parse(rhs.toString())];
if (op === "=") return exp[1] === exp[2];
else if (op === "<>") return exp[1] !== exp[2];
else if (op === ">") return exp[1] > exp[2];
else if (op === ">=") return exp[1] >= exp[2];
else if (op === "<") return exp[1] < exp[2];
else if (op === "<=") return exp[1] <= exp[2];
} else {
let flipOp = 1;
const n = lhs.terms[0].coefficientNumerator;
const d = lhs.terms[0].coefficientDenominator;
if (BI.lt(n, ZERO) || BI.lt(d, ZERO)) flipOp *= -1;
const reciprocal = new Polynomial([
{
indeterminates: new Indeterminates(),
coefficientNumerator: d,
coefficientDenominator: n,
},
]);
lhs = lhs.multiply(reciprocal);
rhs = rhs.multiply(reciprocal);
const keys = lhs.terms[0].indeterminates.sortedKeys;
let invert = lhs.terms[0].indeterminates.map.get(keys[0]) < 0 ? -1 : 0;
for (const t of lhs.terms)
for (const v of t.indeterminates.map.values()) invert += v;
if (invert < 0) {
flipOp *= -1;
lhs = lhs.reciprocal();
rhs = rhs.reciprocal();
}
if (flipOp < 0) exp = [SWAPPED_OPS[op], lhs, rhs];
else exp = [op, lhs, rhs];
}
}
}
// Restore polynomial expressions
exp = exp.map((e) =>
e instanceof Polynomial ? JSON.parse(e.toString()) : e
);
exp = evaluateCallback(exp);
return exp;
}
export function normalize(expr: Expression): Expression {
expr = map(expr, normalizeCallback);
if (expr instanceof Polynomial) {
expr = JSON.parse(expr.toString());
} else if (Array.isArray(expr) && expr[0] === "CASE") {
expr = expr.map((e) =>
e instanceof Polynomial ? JSON.parse(e.toString()) : e
);
}
return expr;
}
function toBoolExprSynth(e: Expression | BoolExprSynth): BoolExprSynth {
if (e instanceof BoolExprSynth) return e;
if (Array.isArray(e)) {
if (e[0] === "CASE")
return new CaseSynth(e.slice(1).map((ee) => toBoolExprSynth(ee)));
return new VarSynth(e);
}
if (e == null) return new NullSynth();
if (e) return new TrueSynth();
return new FalseSynth();
}
function sopToExpression(sop: number[][], context: SynthContext): Expression {
if (!sop.length) return false;
const res: Expression[] = [];
for (const s of sop) {
if (!s.length) return true;
const conjs: Expression[] = [];
for (const i of s) {
let expr = context.getExpression(i >>> 2);
if (!(i & 1) !== !(i & 2)) expr = ["NOT", expr];
if (Array.isArray(expr) && expr[0] === "NOT" && Array.isArray(expr[1])) {
const e: Expression[] = expr[1];
if (e[0] === "IS NULL") expr = ["IS NOT NULL", ...e.slice(1)];
else if (e[0] === "LIKE") expr = ["NOT LIKE", ...e.slice(1)];
else if (e[0] === "=") expr = ["<>", ...e.slice(1)];
else if (e[0] === "<>") expr = ["=", ...e.slice(1)];
else if (e[0] === ">") expr = ["<=", ...e.slice(1)];
else if (e[0] === ">=") expr = ["<", ...e.slice(1)];
else if (e[0] === "<") expr = [">=", ...e.slice(1)];
else if (e[0] === "<=") expr = [">", ...e.slice(1)];
else if (e[0] === "NOT") expr = e[1];
else expr = ["NOT", e];
}
conjs.push(expr);
}
if (conjs.length > 1) res.push(["AND" as any].concat(conjs));
else res.push(conjs[0]);
}
if (res.length > 1) return ["OR" as any].concat(res);
return res[0];
}
function findIsNullDeps(exp: Expression): Expression[] {
if (!Array.isArray(exp)) return [];
const op = exp[0];
if (op === "IS NULL" || op === "IS NOT NULL") return [];
if (op === "FUNC") {
if (exp[1] === "NOW") {
return [];
} else if (exp[1] === "LOWER" || exp[1] === "UPPER") {
return findIsNullDeps(exp[2]);
} else if (exp[1] === "ROUND") {
return exp
.slice(2, 4)
.map((e) => findIsNullDeps(e))
.flat();
}
} else if (op !== "PARAM") {
return exp
.slice(1)
.map((e) => findIsNullDeps(e))
.flat();
}
return [exp];
}
class SynthContext {
private declare _dcSet: number[][];
private declare _variables: Map<string, number>;
private declare _expressions: Map<number, Expression>;
private declare _isNullRelations: Map<number, number[]>;
private declare _isNullVars: Set<number>;
private declare _comparisons: Map<
string,
Map<string, { eq: number; gt: number; lt: number }>
>;
constructor() {
this._dcSet = [];
this._variables = new Map();
this._expressions = new Map();
this._isNullRelations = new Map();
this._isNullVars = new Set();
this._comparisons = new Map();
}
getVariable(exp: Expression): number {
const expStr = JSON.stringify(exp);
if (this._variables.has(expStr)) return this._variables.get(expStr);
const v = this._variables.size;
this._variables.set(expStr, v);
this._expressions.set(v, exp);
this.generateIsNullDc(v);
this.generateComparisionDc(v);
if (
expStr === '["IS NULL",["PARAM","DeviceID.ID"]]' ||
expStr === '["IS NULL",["PARAM","_id"]]'
)
this._dcSet.push([(v << 2) ^ 3]);
return v;
}
private generateIsNullDc(v: number): void {
this._isNullRelations.set(v, []);
const exp = this._expressions.get(v);
const isNull = new Set(
findIsNullDeps(exp).map((e) => this.getVariable(["IS NULL", e]))
);
if (!isNull.size) return;
for (const n of isNull) {
this._isNullVars.add(n);
this._isNullRelations.get(n).push(v);
this._isNullRelations.get(v).push(n);
this._dcSet.push([(n << 2) ^ 3, (v << 2) ^ 1]);
this._dcSet.push([(n << 2) ^ 3, (v << 2) ^ 3]);
}
this._dcSet.push(
[...isNull].map((n) => (n << 2) ^ 2).concat([(v << 2) ^ 0, (v << 2) ^ 2])
);
}
private generateComparisionDc(v: number): void {
const exp = this._expressions.get(v);
if (!Array.isArray(exp)) return;
const op = exp[0];
if (![">", "<", "="].includes(op)) return;
const rhs = exp[2];
const rhsStr = JSON.stringify(rhs);
const lhsStr = JSON.stringify(exp[1]);
let allComps = this._comparisons.get(lhsStr);
if (!allComps) this._comparisons.set(lhsStr, (allComps = new Map()));
if (allComps.has(rhsStr)) return;
const comp = {
eq: -1,
gt: -1,
lt: -1,
};
allComps.set(rhsStr, comp);
comp.eq = this.getVariable(["=", exp[1], exp[2]]);
comp.gt = this.getVariable([">", exp[1], exp[2]]);
comp.lt = this.getVariable(["<", exp[1], exp[2]]);
this._dcSet.push([
(comp.eq << 2) ^ 1,
(comp.gt << 2) ^ 1,
(comp.lt << 2) ^ 1,
]);
this._dcSet.push([(comp.eq << 2) ^ 3, (comp.gt << 2) ^ 3]);
this._dcSet.push([(comp.eq << 2) ^ 3, (comp.lt << 2) ^ 3]);
this._dcSet.push([(comp.gt << 2) ^ 3, (comp.lt << 2) ^ 3]);
const type1 = typeof exp[2];
if (!["boolean", "number", "string"].includes(type1)) return;
for (const [rhs2Str, comp2] of allComps) {
if (comp2 === comp) continue;
const rhs2 = JSON.parse(rhs2Str);
const type2 = typeof rhs2;
if (!["boolean", "number", "string"].includes(type2)) continue;
let cmp = 0;
if (type1 === type2) cmp = rhs > rhs2 ? 1 : -1;
else if (type1 === "string") cmp = 1;
else if (type2 === "string") cmp = -1;
else cmp = +rhs - +rhs2;
const c1 = cmp > 0 ? comp : comp2;
const c2 = cmp > 0 ? comp2 : comp;
// This is the minimum clauses required if all relavent vars
// were included in the DC set.
// this._dcSet.push([(c1.eq << 2) ^ 3, (c2.eq << 2) ^ 3]);
// this._dcSet.push([(c1.lt << 2) ^ 1, (c2.gt << 2) ^ 1]);
// But we use non-minimal set because intermediate vars
// between any two may not be present in the DC set.
this._dcSet.push([(c1.lt << 2) ^ 1, (c2.gt << 2) ^ 1]);
this._dcSet.push([(c1.lt << 2) ^ 1, (c2.eq << 2) ^ 3]);
this._dcSet.push([(c1.lt << 2) ^ 1, (c2.lt << 2) ^ 3]);
this._dcSet.push([(c1.eq << 2) ^ 3, (c2.gt << 2) ^ 1]);
this._dcSet.push([(c1.eq << 2) ^ 3, (c2.eq << 2) ^ 3]);
this._dcSet.push([(c1.eq << 2) ^ 3, (c2.lt << 2) ^ 3]);
this._dcSet.push([(c1.gt << 2) ^ 3, (c2.gt << 2) ^ 1]);
this._dcSet.push([(c1.gt << 2) ^ 3, (c2.eq << 2) ^ 3]);
this._dcSet.push([(c1.gt << 2) ^ 3, (c2.lt << 2) ^ 3]);
}
}
getExpression(v: number): Expression {
return this._expressions.get(v);
}
getIsNullRelations(v: number): number[] {
return this._isNullRelations.get(v);
}
isIsNull(v: number): boolean {
return this._isNullVars.has(v);
}
getDcSet(minterms?: Minterm[]): number[][] {
if (!minterms) return this._dcSet;
const vars = new Set(minterms.flat().map((v) => v >> 2));
for (const comps of this._comparisons.values()) {
for (const comp of comps.values()) {
const c = Object.values(comp).filter((v) => !vars.has(v));
if (c.length === 1) vars.add(c[0]);
}
}
for (const n of this._isNullVars)
if (this._isNullRelations.get(n).some((v) => vars.has(v))) vars.add(n);
const dcSet = this._dcSet.filter((m) => m.every((v) => vars.has(v >> 2)));
return dcSet;
}
}
function sanitizeMinterms(
minterms: number[][],
context: SynthContext
): number[][] {
const res = [] as number[][];
loop: for (const m of minterms) {
const merged: Map<number, number> = new Map();
for (const i of m)
merged.set(i >> 2, (merged.get(i >> 2) || 0) | (1 << (i & 3)));
const minterm: number[] = [];
const perms: number[][] = [];
for (const [k, v] of merged) {
if (v === 0b1010) continue loop;
const isNullVars = context.getIsNullRelations(k);
const t = k << 2;
if (v === 0b0101) {
if (isNullVars.length === 1) minterm.push((isNullVars[0] << 2) ^ 3);
else perms.push(isNullVars.map((n) => (n << 2) ^ 3));
} else if (v === 0b0001) {
perms.push([...isNullVars.map((n) => (n << 2) ^ 3), t ^ 3]);
} else if (v === 0b0100) {
perms.push([...isNullVars.map((n) => (n << 2) ^ 3), t ^ 1]);
} else if (v & 0b1000) {
minterm.push(t ^ 3);
} else if (v & 0b0010) {
minterm.push(t ^ 1);
}
}
let ms = [minterm];
while (perms.length) {
const newMs: number[][] = [];
const perm = perms.pop();
for (const p of perm) newMs.push(...ms.map((mm) => [...mm, p]));
ms = newMs;
}
res.push(...ms);
}
return res;
}
function boolExprSynthToExpression(boolExpr: BoolExprSynth): Expression {
const context = new SynthContext();
let minterms = boolExpr.true(context);
minterms = sanitizeMinterms(minterms, context);
const canRaise = getCanRaiseCallback(context);
const dcSet = context.getDcSet(minterms);
minterms = espresso(minterms, dcSet, { canRaise });
return sopToExpression(minterms, context);
}
function mapCallback(exp: Expression | BoolExprSynth): Expression {
if (!Array.isArray(exp)) return exp as Expression;
if (exp[0] === "CASE") {
exp = exp.slice();
for (let i = 1; i < exp.length; i += 2) exp[i] = toBoolExprSynth(exp[i]);
return exp;
}
const op = exp[0];
if (op === "IS NULL")
return new IsNullSynth(toBoolExprSynth(exp[1])) as unknown as Expression;
if (op === "IS NOT NULL") {
return new NotSynth(
new IsNullSynth(toBoolExprSynth(exp[1]))
) as unknown as Expression;
} else if (op === "NOT") {
return new NotSynth(toBoolExprSynth(exp[1])) as unknown as Expression;
} else if (op === "OR") {
return new OrSynth(
...exp.slice(1).map((a) => toBoolExprSynth(a))
) as unknown as Expression;
} else if (op === "AND") {
return new AndSynth(
...exp.slice(1).map((a) => toBoolExprSynth(a))
) as unknown as Expression;
}
for (let i = 1; i < exp.length; ++i) {
if (exp[i] instanceof BoolExprSynth) {
exp[i] = boolExprSynthToExpression(exp[i]);
} else if (Array.isArray(exp[i]) && exp[i][0] === "CASE") {
for (let j = 2; j < exp[i].length; j += 2) {
if (exp[i][j] instanceof BoolExprSynth)
exp[i][j] = boolExprSynthToExpression(exp[i][j]);
}
}
}
return exp;
}
function getCanRaiseCallback(
context: SynthContext
): (idx: number, set: Set<number>) => boolean {
return (idx: number, set: Set<number>): boolean => {
const i = idx >> 2;
const vars = context.getIsNullRelations(i);
if (!context.isIsNull(i)) return !(idx & 1) || !set.has(idx ^ 3);
for (const k of vars) {
if (set.has((k << 2) ^ 1)) continue;
if (set.has((k << 2) ^ 3)) continue;
if (set.has((k << 2) ^ 0)) return false;
if (set.has((k << 2) ^ 2)) return false;
}
return true;
};
}
export function minimize(expr: Expression, boolean = false): Expression {
expr = normalize(expr);
expr = map(expr, mapCallback);
if (Array.isArray(expr) && expr[0] === "CASE") {
if (!boolean) {
const context = new SynthContext();
const whens = expr.filter((e, i) => i % 2).map((e) => e.true(context));
const caseDcSet: Minterm[] = [];
const canRaise = getCanRaiseCallback(context);
const res: Expression = ["CASE"];
for (let i = 1; i < expr.length; i += 2) {
let minterms = sanitizeMinterms(whens[(i - 1) / 2], context);
const dcSet = context.getDcSet(minterms.concat(caseDcSet));
minterms = espresso(minterms, dcSet, { canRaise });
if (!minterms.length) continue;
const w = sopToExpression(minterms, context);
let t = expr[i + 1];
if (t instanceof BoolExprSynth) t = boolExprSynthToExpression(t);
res.push(w, t);
if (w === true) break;
caseDcSet.push(...minterms);
}
while (res[res.length - 1] == null) res.splice(-2);
if (res.length < 3) return null;
return res;
}
expr = toBoolExprSynth(expr) as unknown as Expression;
}
if (boolean) expr = toBoolExprSynth(expr) as unknown as Expression;
if (expr instanceof BoolExprSynth) expr = boolExprSynthToExpression(expr);
return expr;
}
export function unionDiff(
expr1: Expression,
expr2: Expression
): [Expression, Expression] {
expr2 = normalize(expr2);
if (!expr2) return [expr1, false];
expr2 = map(expr2, mapCallback);
if (!expr1) {
if (Array.isArray(expr2) && expr2[0] === "CASE")
expr2 = toBoolExprSynth(expr2) as unknown as Expression;
if (expr2 instanceof BoolExprSynth)
expr2 = boolExprSynthToExpression(expr2);
return [expr2, expr2];
}
const b2 = toBoolExprSynth(expr2);
expr1 = normalize(expr1);
expr1 = map(expr1, mapCallback);
const b1 = toBoolExprSynth(expr1);
const context = new SynthContext();
const expr2Minterms = b2.true(context);
const expr1Minterms = b1.true(context);
const expr1NullMinterms = b1.null(context);
const expr1FalseMinterms = b1.false(context);
const unionMinterms = sanitizeMinterms(
[...expr1Minterms, ...expr2Minterms],
context
);
const diffMinterms = sanitizeMinterms(
complement([
...complement([...expr1NullMinterms, ...expr1FalseMinterms]),
...complement(expr2Minterms),
]),
context
);
const canRaise = getCanRaiseCallback(context);
const union = espresso(unionMinterms, context.getDcSet(unionMinterms), {
canRaise,
});
const diff = espresso(diffMinterms, context.getDcSet(diffMinterms), {
canRaise,
});
return [sopToExpression(union, context), sopToExpression(diff, context)];
}
export function covers(expr1: Expression, expr2: Expression): boolean {
expr2 = normalize(expr2);
if (!expr2) return true;
expr1 = normalize(expr1);
if (!Array.isArray(expr1)) return !!expr1;
expr1 = map(expr1, mapCallback);
const b1 = toBoolExprSynth(expr1);
expr2 = map(expr2, mapCallback);
const b2 = toBoolExprSynth(expr2);
const context = new SynthContext();
const expr1Minterms = b1.true(context);
const expr2Minterms = b2.true(context);
return tautology([
...complement(expr2Minterms),
...context.getDcSet(),
...expr1Minterms,
]);
}