simple-squiggle

simplifyConstant.js (14268B)

---

 // TODO this could be improved by simplifying seperated constants under associative and commutative operators
 import { isFraction, isMatrix, isNode, isArrayNode, isConstantNode, isIndexNode, isObjectNode, isOperatorNode } from '../../../utils/is.js';
 import { factory } from '../../../utils/factory.js';
 import { createUtil } from './util.js';
 import { noBignumber, noFraction } from '../../../utils/noop.js';
 var name = 'simplifyConstant';
 var dependencies = ['typed', 'config', 'mathWithTransform', 'matrix', '?fraction', '?bignumber', 'AccessorNode', 'ArrayNode', 'ConstantNode', 'FunctionNode', 'IndexNode', 'ObjectNode', 'OperatorNode', 'SymbolNode'];
 export var createSimplifyConstant = /* #__PURE__ */factory(name, dependencies, _ref => {
   var {
     typed,
     config,
     mathWithTransform,
     matrix,
     fraction,
     bignumber,
     AccessorNode,
     ArrayNode,
     ConstantNode,
     FunctionNode,
     IndexNode,
     ObjectNode,
     OperatorNode,
     SymbolNode
   } = _ref;
   var {
     isCommutative,
     isAssociative,
     allChildren,
     createMakeNodeFunction
   } = createUtil({
     FunctionNode,
     OperatorNode,
     SymbolNode
   });
 
   function simplifyConstant(expr, options) {
     return _ensureNode(foldFraction(expr, options));
   }
 
   function _removeFractions(thing) {
     if (isFraction(thing)) {
       return thing.valueOf();
     }
 
     if (thing instanceof Array) {
       return thing.map(_removeFractions);
     }
 
     if (isMatrix(thing)) {
       return matrix(_removeFractions(thing.valueOf()));
     }
 
     return thing;
   }
 
   function _eval(fnname, args, options) {
     try {
       return mathWithTransform[fnname].apply(null, args);
     } catch (ignore) {
       // sometimes the implicit type conversion causes the evaluation to fail, so we'll try again after removing Fractions
       args = args.map(_removeFractions);
       return _toNumber(mathWithTransform[fnname].apply(null, args), options);
     }
   }
 
   var _toNode = typed({
     Fraction: _fractionToNode,
     number: function number(n) {
       if (n < 0) {
         return unaryMinusNode(new ConstantNode(-n));
       }
 
       return new ConstantNode(n);
     },
     BigNumber: function BigNumber(n) {
       if (n < 0) {
         return unaryMinusNode(new ConstantNode(-n));
       }
 
       return new ConstantNode(n); // old parameters: (n.toString(), 'number')
     },
     Complex: function Complex(s) {
       throw new Error('Cannot convert Complex number to Node');
     },
     string: function string(s) {
       return new ConstantNode(s);
     },
     Matrix: function Matrix(m) {
       return new ArrayNode(m.valueOf().map(e => _toNode(e)));
     }
   });
 
   function _ensureNode(thing) {
     if (isNode(thing)) {
       return thing;
     }
 
     return _toNode(thing);
   } // convert a number to a fraction only if it can be expressed exactly,
   // and when both numerator and denominator are small enough
 
 
   function _exactFraction(n, options) {
     var exactFractions = options && options.exactFractions !== false;
 
     if (exactFractions && isFinite(n) && fraction) {
       var f = fraction(n);
       var fractionsLimit = options && typeof options.fractionsLimit === 'number' ? options.fractionsLimit : Infinity; // no limit by default
 
       if (f.valueOf() === n && f.n < fractionsLimit && f.d < fractionsLimit) {
         return f;
       }
     }
 
     return n;
   } // Convert numbers to a preferred number type in preference order: Fraction, number, Complex
   // BigNumbers are left alone
 
 
   var _toNumber = typed({
     'string, Object': function stringObject(s, options) {
       if (config.number === 'BigNumber') {
         if (bignumber === undefined) {
           noBignumber();
         }
 
         return bignumber(s);
       } else if (config.number === 'Fraction') {
         if (fraction === undefined) {
           noFraction();
         }
 
         return fraction(s);
       } else {
         var n = parseFloat(s);
         return _exactFraction(n, options);
       }
     },
     'Fraction, Object': function FractionObject(s, options) {
       return s;
     },
     // we don't need options here
     'BigNumber, Object': function BigNumberObject(s, options) {
       return s;
     },
     // we don't need options here
     'number, Object': function numberObject(s, options) {
       return _exactFraction(s, options);
     },
     'Complex, Object': function ComplexObject(s, options) {
       if (s.im !== 0) {
         return s;
       }
 
       return _exactFraction(s.re, options);
     },
     'Matrix, Object': function MatrixObject(s, options) {
       return matrix(_exactFraction(s.valueOf()));
     },
     'Array, Object': function ArrayObject(s, options) {
       return s.map(_exactFraction);
     }
   });
 
   function unaryMinusNode(n) {
     return new OperatorNode('-', 'unaryMinus', [n]);
   }
 
   function _fractionToNode(f) {
     var n;
     var vn = f.s * f.n;
 
     if (vn < 0) {
       n = new OperatorNode('-', 'unaryMinus', [new ConstantNode(-vn)]);
     } else {
       n = new ConstantNode(vn);
     }
 
     if (f.d === 1) {
       return n;
     }
 
     return new OperatorNode('/', 'divide', [n, new ConstantNode(f.d)]);
   }
   /* Handles constant indexing of ArrayNodes, matrices, and ObjectNodes */
 
 
   function _foldAccessor(obj, index, options) {
     if (!isIndexNode(index)) {
       // don't know what to do with that...
       return new AccessorNode(_ensureNode(obj), _ensureNode(index));
     }
 
     if (isArrayNode(obj) || isMatrix(obj)) {
       var remainingDims = Array.from(index.dimensions);
       /* We will resolve constant indices one at a time, looking
        * just in the first or second dimensions because (a) arrays
        * of more than two dimensions are likely rare, and (b) pulling
        * out the third or higher dimension would be pretty intricate.
        * The price is that we miss simplifying [..3d array][x,y,1]
        */
 
       while (remainingDims.length > 0) {
         if (isConstantNode(remainingDims[0]) && typeof remainingDims[0].value !== 'string') {
           var first = _toNumber(remainingDims.shift().value, options);
 
           if (isArrayNode(obj)) {
             obj = obj.items[first - 1];
           } else {
             // matrix
             obj = obj.valueOf()[first - 1];
 
             if (obj instanceof Array) {
               obj = matrix(obj);
             }
           }
         } else if (remainingDims.length > 1 && isConstantNode(remainingDims[1]) && typeof remainingDims[1].value !== 'string') {
           var second = _toNumber(remainingDims[1].value, options);
 
           var tryItems = [];
           var fromItems = isArrayNode(obj) ? obj.items : obj.valueOf();
 
           for (var item of fromItems) {
             if (isArrayNode(item)) {
               tryItems.push(item.items[second - 1]);
             } else if (isMatrix(obj)) {
               tryItems.push(item[second - 1]);
             } else {
               break;
             }
           }
 
           if (tryItems.length === fromItems.length) {
             if (isArrayNode(obj)) {
               obj = new ArrayNode(tryItems);
             } else {
               // matrix
               obj = matrix(tryItems);
             }
 
             remainingDims.splice(1, 1);
           } else {
             // extracting slice along 2nd dimension failed, give up
             break;
           }
         } else {
           // neither 1st or 2nd dimension is constant, give up
           break;
         }
       }
 
       if (remainingDims.length === index.dimensions.length) {
         /* No successful constant indexing */
         return new AccessorNode(_ensureNode(obj), index);
       }
 
       if (remainingDims.length > 0) {
         /* Indexed some but not all dimensions */
         index = new IndexNode(remainingDims);
         return new AccessorNode(_ensureNode(obj), index);
       }
       /* All dimensions were constant, access completely resolved */
 
 
       return obj;
     }
 
     if (isObjectNode(obj) && index.dimensions.length === 1 && isConstantNode(index.dimensions[0])) {
       var key = index.dimensions[0].value;
 
       if (key in obj.properties) {
         return obj.properties[key];
       }
 
       return new ConstantNode(); // undefined
     }
     /* Don't know how to index this sort of obj, at least not with this index */
 
 
     return new AccessorNode(_ensureNode(obj), index);
   }
   /*
    * Create a binary tree from a list of Fractions and Nodes.
    * Tries to fold Fractions by evaluating them until the first Node in the list is hit, so
    * `args` should be sorted to have the Fractions at the start (if the operator is commutative).
    * @param args - list of Fractions and Nodes
    * @param fn - evaluator for the binary operation evaluator that accepts two Fractions
    * @param makeNode - creates a binary OperatorNode/FunctionNode from a list of child Nodes
    * if args.length is 1, returns args[0]
    * @return - Either a Node representing a binary expression or Fraction
    */
 
 
   function foldOp(fn, args, makeNode, options) {
     return args.reduce(function (a, b) {
       if (!isNode(a) && !isNode(b)) {
         try {
           return _eval(fn, [a, b], options);
         } catch (ignoreandcontinue) {}
 
         a = _toNode(a);
         b = _toNode(b);
       } else if (!isNode(a)) {
         a = _toNode(a);
       } else if (!isNode(b)) {
         b = _toNode(b);
       }
 
       return makeNode([a, b]);
     });
   } // destroys the original node and returns a folded one
 
 
   function foldFraction(node, options) {
     switch (node.type) {
       case 'SymbolNode':
         return node;
 
       case 'ConstantNode':
         switch (typeof node.value) {
           case 'number':
             return _toNumber(node.value, options);
 
           case 'string':
             return node.value;
 
           default:
             if (!isNaN(node.value)) return _toNumber(node.value, options);
         }
 
         return node;
 
       case 'FunctionNode':
         if (mathWithTransform[node.name] && mathWithTransform[node.name].rawArgs) {
           return node;
         }
 
         {
           // Process operators as OperatorNode
           var operatorFunctions = ['add', 'multiply'];
 
           if (operatorFunctions.indexOf(node.name) === -1) {
             var args = node.args.map(arg => foldFraction(arg, options)); // If all args are numbers
 
             if (!args.some(isNode)) {
               try {
                 return _eval(node.name, args, options);
               } catch (ignoreandcontinue) {}
             } // Size of a matrix does not depend on entries
 
 
             if (node.name === 'size' && args.length === 1 && isArrayNode(args[0])) {
               var sz = [];
               var section = args[0];
 
               while (isArrayNode(section)) {
                 sz.push(section.items.length);
                 section = section.items[0];
               }
 
               return matrix(sz);
             } // Convert all args to nodes and construct a symbolic function call
 
 
             return new FunctionNode(node.name, args.map(_ensureNode));
           } else {// treat as operator
           }
         }
 
       /* falls through */
 
       case 'OperatorNode':
         {
           var fn = node.fn.toString();
 
           var _args;
 
           var res;
           var makeNode = createMakeNodeFunction(node);
 
           if (isOperatorNode(node) && node.isUnary()) {
             _args = [foldFraction(node.args[0], options)];
 
             if (!isNode(_args[0])) {
               res = _eval(fn, _args, options);
             } else {
               res = makeNode(_args);
             }
           } else if (isAssociative(node, options.context)) {
             _args = allChildren(node, options.context);
             _args = _args.map(arg => foldFraction(arg, options));
 
             if (isCommutative(fn, options.context)) {
               // commutative binary operator
               var consts = [];
               var vars = [];
 
               for (var i = 0; i < _args.length; i++) {
                 if (!isNode(_args[i])) {
                   consts.push(_args[i]);
                 } else {
                   vars.push(_args[i]);
                 }
               }
 
               if (consts.length > 1) {
                 res = foldOp(fn, consts, makeNode, options);
                 vars.unshift(res);
                 res = foldOp(fn, vars, makeNode, options);
               } else {
                 // we won't change the children order since it's not neccessary
                 res = foldOp(fn, _args, makeNode, options);
               }
             } else {
               // non-commutative binary operator
               res = foldOp(fn, _args, makeNode, options);
             }
           } else {
             // non-associative binary operator
             _args = node.args.map(arg => foldFraction(arg, options));
             res = foldOp(fn, _args, makeNode, options);
           }
 
           return res;
         }
 
       case 'ParenthesisNode':
         // remove the uneccessary parenthesis
         return foldFraction(node.content, options);
 
       case 'AccessorNode':
         return _foldAccessor(foldFraction(node.object, options), foldFraction(node.index, options), options);
 
       case 'ArrayNode':
         {
           var foldItems = node.items.map(item => foldFraction(item, options));
 
           if (foldItems.some(isNode)) {
             return new ArrayNode(foldItems.map(_ensureNode));
           }
           /* All literals -- return a Matrix so we can operate on it */
 
 
           return matrix(foldItems);
         }
 
       case 'IndexNode':
         {
           return new IndexNode(node.dimensions.map(n => simplifyConstant(n, options)));
         }
 
       case 'ObjectNode':
         {
           var foldProps = {};
 
           for (var prop in node.properties) {
             foldProps[prop] = simplifyConstant(node.properties[prop], options);
           }
 
           return new ObjectNode(foldProps);
         }
 
       case 'AssignmentNode':
       /* falls through */
 
       case 'BlockNode':
       /* falls through */
 
       case 'FunctionAssignmentNode':
       /* falls through */
 
       case 'RangeNode':
       /* falls through */
 
       case 'ConditionalNode':
       /* falls through */
 
       default:
         throw new Error("Unimplemented node type in simplifyConstant: ".concat(node.type));
     }
   }
 
   return simplifyConstant;
 });