Files
audita/internal/core/chunking/tokens.go

56 lines
1.7 KiB
Go

package chunking
import (
"strings"
"unicode"
)
// TokenEstimator provides a deterministic token estimation suitable for prompt budgeting.
// The estimator is approximate but stable, isolated, and replaceable.
type TokenEstimator interface {
EstimateTokens(text string) int
}
// SimpleTokenEstimator provides a basic deterministic token estimation.
// This uses a simple heuristic based on word count and punctuation.
type SimpleTokenEstimator struct{}
// NewSimpleTokenEstimator creates a new simple token estimator.
func NewSimpleTokenEstimator() *SimpleTokenEstimator {
return &SimpleTokenEstimator{}
}
// EstimateTokens provides a rough estimate of the number of tokens in the given text.
// This implementation uses a simple heuristic: count words and punctuation as tokens.
// The estimate is deterministic and stable for the same input text.
func (e *SimpleTokenEstimator) EstimateTokens(text string) int {
if text == "" {
return 0
}
// Simple heuristic: split on whitespace and count non-empty segments
words := strings.Fields(text)
tokenCount := len(words)
// Add some estimate for punctuation that might be separate tokens
punctuationCount := 0
for _, r := range text {
if unicode.IsPunct(r) && r != '\'' && r != '-' && r != '_' {
punctuationCount++
}
}
// Rough estimate: each word is a token, plus half the punctuation as separate tokens
return tokenCount + (punctuationCount / 2)
}
// ConstTokenEstimator returns a constant token count for testing purposes.
type ConstTokenEstimator struct {
Tokens int
}
// EstimateTokens returns the configured constant token count.
func (e *ConstTokenEstimator) EstimateTokens(text string) int {
return e.Tokens
}