M.V. Hutz
f3b9137d75
Closes #26 - Added -i flag to select interpreter (lambda or debruijn) - Created debruijn package with Expression interface - Variable contains index and optional label - Abstraction contains only body (no parameter) - Application structure remains similar - Implemented De Bruijn reduction without variable renaming - Shift operation handles index adjustments - Substitute replaces by index instead of name - Abstracted Engine into interface with two implementations - LambdaEngine: original named variable engine - DeBruijnEngine: new index-based engine - Added conversion functions between representations - LambdaToDeBruijn: converts named to indexed - DeBruijnToLambda: converts indexed back to named - SaccharineToDeBruijn: direct saccharine to De Bruijn - Updated main to switch engines based on -i flag - All test samples pass with both engines Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
39 lines
742 B
Go
39 lines
742 B
Go
package debruijn
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import (
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"fmt"
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"strings"
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)
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type stringifyVisitor struct {
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builder strings.Builder
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}
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func (v *stringifyVisitor) VisitVariable(a *Variable) {
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if a.label != "" {
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v.builder.WriteString(a.label)
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} else {
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v.builder.WriteString(fmt.Sprintf("%d", a.index))
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}
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}
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func (v *stringifyVisitor) VisitAbstraction(f *Abstraction) {
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v.builder.WriteRune('\\')
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v.builder.WriteRune('.')
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f.body.Accept(v)
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}
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func (v *stringifyVisitor) VisitApplication(c *Application) {
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v.builder.WriteRune('(')
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c.abstraction.Accept(v)
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v.builder.WriteRune(' ')
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c.argument.Accept(v)
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v.builder.WriteRune(')')
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}
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func Stringify(e Expression) string {
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b := &stringifyVisitor{builder: strings.Builder{}}
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e.Accept(b)
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return b.builder.String()
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}
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