47 lines
774 B
Go
47 lines
774 B
Go
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package main
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import (
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"fmt"
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"strings"
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)
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type AstToRPN struct {
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str strings.Builder
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}
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func (as AstToRPN) String(expr Expr) string {
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if expr == nil {
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return ""
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}
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expr.accept(&as)
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return as.str.String()
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}
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func (as *AstToRPN) visitBinary(b *Binary) any {
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b.left.accept(as)
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as.str.WriteString(" ")
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b.right.accept(as)
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as.str.WriteString(" ")
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as.str.WriteString(b.op.lexeme)
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return nil
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}
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func (as *AstToRPN) visitLiteral(l *Literal) any {
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as.str.WriteString(fmt.Sprintf("%v", l.value))
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return nil
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}
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func (as *AstToRPN) visitGrouping(g *Grouping) any {
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g.expression.accept(as)
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as.str.WriteString(" group")
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return nil
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}
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func (as *AstToRPN) visitUnary(u *Unary) any {
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u.right.accept(as)
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as.str.WriteString(fmt.Sprintf(" %s", u.op.lexeme))
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return nil
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}
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