85 lines
1.9 KiB
Go
85 lines
1.9 KiB
Go
// operator-sum.go
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package expr
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import (
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"fmt"
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)
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//-------- plus term
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func newPlusTerm(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: priSum,
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evalFunc: evalPlus,
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}
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}
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func evalPlus(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) && isNumberString(rightValue)) || (isString(rightValue) && isNumberString(leftValue)) {
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v = fmt.Sprintf("%v%v", leftValue, rightValue)
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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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//-------- minus term
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func newMinusTerm(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: priSum,
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evalFunc: evalMinus,
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}
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}
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func evalMinus(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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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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// init
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func init() {
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registerTermConstructor(SymPlus, newPlusTerm)
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registerTermConstructor(SymMinus, newMinusTerm)
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}
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