/
string_evaluator.go
66 lines (54 loc) · 1.7 KB
/
string_evaluator.go
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package yqlib
import (
"bufio"
"bytes"
"container/list"
"strings"
)
type StringEvaluator interface {
Evaluate(expression string, input string, encoder Encoder, decoder Decoder) (string, error)
EvaluateAll(expression string, input string, encoder Encoder, decoder Decoder) (string, error)
}
type stringEvaluator struct {
treeNavigator DataTreeNavigator
}
func NewStringEvaluator() StringEvaluator {
return &stringEvaluator{
treeNavigator: NewDataTreeNavigator(),
}
}
func (s *stringEvaluator) EvaluateAll(expression string, input string, encoder Encoder, decoder Decoder) (string, error) {
reader := bufio.NewReader(strings.NewReader(input))
var documents *list.List
var results *list.List
var err error
if documents, err = ReadDocuments(reader, decoder); err != nil {
return "", err
}
evaluator := NewAllAtOnceEvaluator()
if results, err = evaluator.EvaluateCandidateNodes(expression, documents); err != nil {
return "", err
}
out := new(bytes.Buffer)
printer := NewPrinter(encoder, NewSinglePrinterWriter(out))
if err := printer.PrintResults(results); err != nil {
return "", err
}
return out.String(), nil
}
func (s *stringEvaluator) Evaluate(expression string, input string, encoder Encoder, decoder Decoder) (string, error) {
// Use bytes.Buffer for output of string
out := new(bytes.Buffer)
printer := NewPrinter(encoder, NewSinglePrinterWriter(out))
InitExpressionParser()
node, err := ExpressionParser.ParseExpression(expression)
if err != nil {
return "", err
}
reader := bufio.NewReader(strings.NewReader(input))
evaluator := NewStreamEvaluator()
if _, err := evaluator.Evaluate("", reader, node, printer, decoder); err != nil {
return "", err
}
return out.String(), nil
}