134 lines
2.9 KiB
Go
134 lines
2.9 KiB
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-prod.go
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package expr
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import (
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"errors"
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"strings"
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)
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//-------- multiply term
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func newMultiplyTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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class: classOperator,
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kind: kindUnknown,
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children: make([]*term, 0, 2),
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position: posInfix,
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priority: priProduct,
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evalFunc: evalMultiply,
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}
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}
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func evalMultiply(ctx exprContext, self *term) (v any, err error) {
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var leftValue, rightValue any
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if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
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return
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}
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if isString(leftValue) && isInteger(rightValue) {
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s, _ := leftValue.(string)
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n, _ := rightValue.(int64)
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v = strings.Repeat(s, int(n))
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} else if isNumber(leftValue) && isNumber(rightValue) {
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if isFloat(leftValue) || isFloat(rightValue) {
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v = numAsFloat(leftValue) * numAsFloat(rightValue)
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} else {
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leftInt, _ := leftValue.(int64)
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rightInt, _ := rightValue.(int64)
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v = leftInt * rightInt
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}
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} else {
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err = self.errIncompatibleTypes(leftValue, rightValue)
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}
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return
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}
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//-------- divide term
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func newDivideTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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class: classOperator,
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kind: kindUnknown,
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children: make([]*term, 0, 2),
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position: posInfix,
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priority: priProduct,
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evalFunc: evalDivide,
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}
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}
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func evalDivide(ctx exprContext, self *term) (v any, err error) {
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var leftValue, rightValue any
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if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
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return
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}
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if isNumber(leftValue) && isNumber(rightValue) {
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if isFloat(leftValue) || isFloat(rightValue) {
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d := numAsFloat(rightValue)
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if d == 0.0 {
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err = errors.New("division by zero")
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} else {
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v = numAsFloat(leftValue) / d
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}
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} else {
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leftInt, _ := leftValue.(int64)
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if rightInt, _ := rightValue.(int64); rightInt == 0 {
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err = errors.New("division by zero")
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} else {
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v = leftInt / rightInt
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}
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}
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} else {
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err = self.errIncompatibleTypes(leftValue, rightValue)
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}
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return
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}
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//-------- divide as float term
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func newDivideAsFloatTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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class: classOperator,
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kind: kindUnknown,
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children: make([]*term, 0, 2),
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position: posInfix,
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priority: priProduct,
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evalFunc: evalDivideAsFloat,
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}
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}
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func evalDivideAsFloat(ctx exprContext, self *term) (v any, err error) {
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var leftValue, rightValue any
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if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
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return
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}
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if isNumber(leftValue) && isNumber(rightValue) {
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d := numAsFloat(rightValue)
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if d == 0.0 {
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err = errors.New("division by zero")
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} else {
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v = numAsFloat(leftValue) / d
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}
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} else {
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err = self.errIncompatibleTypes(leftValue, rightValue)
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}
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return
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}
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// init
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func init() {
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registerTermConstructor(SymStar, newMultiplyTerm)
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registerTermConstructor(SymSlash, newDivideTerm)
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registerTermConstructor(SymDotSlash, newDivideAsFloatTerm)
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}
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