An extensible logical tree evaluator, written on node.js.
npm install marina-treemarina-tree
===========
An extensible logical tree evaluator.
npm i marina-tree
The same fact will be evaluated in all functions in the tree.
``javascript
const Marina = require('marina-tree');
// Functions definition
const myFuncs = {
isAnArray: (param) => {
return param instanceof Array;
},
isANumber: (param) => {
return typeof param === 'number';
},
isOdd: (param) => {
return param % 2 === 1;
},
};
// Initialize with my functions and a string (wildcard) that will indicate nesting.
const marina = new Marina(myFuncs, '*');
// Build my conditions tree
const myTree = {
funcs: ['isAnArray', '*'],
facts: [
null, // Padding
{
funcs: ['isANumber', 'isOdd'],
operator: 'and',
}
],
operator: 'or',
};
console.log(marina.eval(myTree, 2)); // false
console.log(marina.eval(myTree, 3)); // true
console.log(marina.eval(myTree, {})); // false
console.log(marina.eval(myTree, [])); // true
`
`javascript
const Marina = require('marina-tree');
// Functions definition
const myFuncs = {
isAnArray: (param) => {
return param instanceof Array;
},
isANumber: (param) => {
return typeof param === 'number';
},
isGte10: (param) => {
return param >= 10;
},
isLte100: (param) => {
return param <= 100;
},
isAFunction: (param) => {
return typeof param === 'function';
},
};
// Initialize with my functions and a string (wildcard) that will indicate nesting.
const marina = new Marina(myFuncs, '*');
// Build my conditions tree
const myTree = {
funcs: ['', ''],
facts: [
{
funcs: ['isANumber', 'isGte10', 'isLte100'],
operator: 'and',
},
{
funcs: ['isANumber', '*'],
facts: [
null, // Padding
{
funcs: ['isANumber'],
operator: 'not',
}
],
operator: 'or',
},
],
operator: 'or',
};
console.log(marina.eval(myTree, 2)); // false
console.log(marina.eval(myTree, 3)); // false
console.log(marina.eval(myTree, {})); // true
console.log(marina.eval(myTree, [])); // true
console.log(marina.eval(myTree, 9)); // false
console.log(marina.eval(myTree, 10)); // true
console.log(marina.eval(myTree, 100)); // true
console.log(marina.eval(myTree, 101)); // false
console.log(marina.eval(myTree, (() => console.log('is a function')))); // true
`
Each function will receive the same fact + a specific argument.
`javascript
const Marina = require('marina-tree');
// Definition of more generic and reusable functions
const myFuncs = {
gte: (singleFact, specificArg) => {
return singleFact[specificArg.field] >= specificArg.value;
},
lte: (singleFact, specificArg) => {
return singleFact[specificArg.field] <= specificArg.value;
},
in: (singleFact, specificArg) => {
return specificArg.value.indexOf(singleFact[specificArg.field]) > -1;
},
};
// Initialize with my functions and a string (wildcard) that will indicate nesting.
const marina = new Marina(myFuncs, '*');
// Build my conditions tree
const myTree = {
funcs: ['', '', '*'],
facts: [
{
funcs: ['gte', 'lte'],
operator: 'and',
},
{
funcs: ['*', 'in'],
facts: [
{
funcs: ['in', 'gte'],
operator: 'and',
},
null, // Padding
],
operator: 'or',
},
{
funcs: ['in'],
operator: 'not',
},
],
operator: 'and',
};
const nestedArgs = [
[
{
field: 'age',
value: 20,
},
{
field: 'age',
value: 80,
},
],
[
[
{
field: 'lang',
value: ['java', 'c++'],
},
{
field: 'exp',
value: 5,
},
],
{
field: 'lang',
value: ['cobol'],
},
],
[
{
field: 'lang',
value: ['php']
},
],
];
const persons = [
{
age: 20,
lang: 'c++',
exp: 2,
},
{
age: 25,
lang: 'java',
exp: 5,
},
{
age: 60,
lang: 'cobol',
exp: 30,
},
{
age: 30,
lang: 'php',
exp: 10,
},
];
console.log(marina.eval(myTree, persons[0], nestedArgs)); // false
console.log(marina.eval(myTree, persons[1], nestedArgs)); // true
console.log(marina.eval(myTree, persons[2], nestedArgs)); // true
console.log(marina.eval(myTree, persons[3], nestedArgs)); // false
``
* and
* nand
* or
* xor
* not (unary)
* none (unary)
* ... (alias for none) (unary)
MIT