42 lines
913 B
Go
42 lines
913 B
Go
package optimizer
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import (
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. "github.com/antonmedv/expr/ast"
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)
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type constRange struct{}
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func (*constRange) Enter(*Node) {}
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func (*constRange) Exit(node *Node) {
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switch n := (*node).(type) {
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case *BinaryNode:
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if n.Operator == ".." {
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if min, ok := n.Left.(*IntegerNode); ok {
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if max, ok := n.Right.(*IntegerNode); ok {
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size := max.Value - min.Value + 1
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// In case the max < min, patch empty slice
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// as max must be greater than equal to min.
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if size < 1 {
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Patch(node, &ConstantNode{
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Value: make([]int, 0),
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})
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return
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}
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// In this case array is too big. Skip generation,
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// and wait for memory budget detection on runtime.
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if size > 1e6 {
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return
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}
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value := make([]int, size)
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for i := range value {
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value[i] = min.Value + i
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}
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Patch(node, &ConstantNode{
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Value: value,
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})
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}
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}
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}
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}
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}
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