feat: extract output with regexes from LLMs (#3491)

* feat: extract output with regexes from LLMs

This changset adds `extract_regex` to the LLM config. It is a list of
regexes that can match output and will be used to re extract text from
the LLM output. This is particularly useful for LLMs which outputs final
results into tags.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* Add tests, enhance output in case of configuration error

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

---------

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/backend/backend_suite_test.go

@@ -0,0 +1,13 @@
+package backend_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestBackend(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Backend test suite")
+}

core/backend/llm.go

@@ -9,6 +9,8 @@ import (
 	"sync"
 	"unicode/utf8"
 
+	"github.com/rs/zerolog/log"
+
 	"github.com/mudler/LocalAI/core/config"
 	"github.com/mudler/LocalAI/core/schema"
 
@@ -181,13 +183,37 @@ func Finetune(config config.BackendConfig, input, prediction string) string {
 		mu.Lock()
 		reg, ok := cutstrings[c]
 		if !ok {
-			cutstrings[c] = regexp.MustCompile(c)
+			r, err := regexp.Compile(c)
+			if err != nil {
+				log.Fatal().Err(err).Msg("failed to compile regex")
+			}
+			cutstrings[c] = r
 			reg = cutstrings[c]
 		}
 		mu.Unlock()
 		prediction = reg.ReplaceAllString(prediction, "")
 	}
 
+	// extract results from the response which can be for instance inside XML tags
+	var predResult string
+	for _, r := range config.ExtractRegex {
+		mu.Lock()
+		reg, ok := cutstrings[r]
+		if !ok {
+			regex, err := regexp.Compile(r)
+			if err != nil {
+				log.Fatal().Err(err).Msg("failed to compile regex")
+			}
+			cutstrings[r] = regex
+			reg = regex
+		}
+		mu.Unlock()
+		predResult += reg.FindString(prediction)
+	}
+	if predResult != "" {
+		prediction = predResult
+	}
+
 	for _, c := range config.TrimSpace {
 		prediction = strings.TrimSpace(strings.TrimPrefix(prediction, c))
 	}

core/backend/llm_test.go

@@ -0,0 +1,109 @@
+package backend_test
+
+import (
+	. "github.com/mudler/LocalAI/core/backend"
+	"github.com/mudler/LocalAI/core/config"
+	"github.com/mudler/LocalAI/core/schema"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("LLM tests", func() {
+	Context("Finetune LLM output", func() {
+		var (
+			testConfig config.BackendConfig
+			input      string
+			prediction string
+			result     string
+		)
+
+		BeforeEach(func() {
+			testConfig = config.BackendConfig{
+				PredictionOptions: schema.PredictionOptions{
+					Echo: false,
+				},
+				LLMConfig: config.LLMConfig{
+					Cutstrings:   []string{`<.*?>`},                  // Example regex for removing XML tags
+					ExtractRegex: []string{`<result>(.*?)</result>`}, // Example regex to extract from tags
+					TrimSpace:    []string{" ", "\n"},
+					TrimSuffix:   []string{".", "!"},
+				},
+			}
+		})
+
+		Context("when echo is enabled", func() {
+			BeforeEach(func() {
+				testConfig.Echo = true
+				input = "Hello"
+				prediction = "World"
+			})
+
+			It("should prepend input to prediction", func() {
+				result = Finetune(testConfig, input, prediction)
+				Expect(result).To(Equal("HelloWorld"))
+			})
+		})
+
+		Context("when echo is disabled", func() {
+			BeforeEach(func() {
+				testConfig.Echo = false
+				input = "Hello"
+				prediction = "World"
+			})
+
+			It("should not modify the prediction with input", func() {
+				result = Finetune(testConfig, input, prediction)
+				Expect(result).To(Equal("World"))
+			})
+		})
+
+		Context("when cutstrings regex is applied", func() {
+			BeforeEach(func() {
+				input = ""
+				prediction = "<div>Hello</div> World"
+			})
+
+			It("should remove substrings matching cutstrings regex", func() {
+				result = Finetune(testConfig, input, prediction)
+				Expect(result).To(Equal("Hello World"))
+			})
+		})
+
+		Context("when extract regex is applied", func() {
+			BeforeEach(func() {
+				input = ""
+				prediction = "<response><result>42</result></response>"
+			})
+
+			It("should extract substrings matching the extract regex", func() {
+				result = Finetune(testConfig, input, prediction)
+				Expect(result).To(Equal("42"))
+			})
+		})
+
+		Context("when trimming spaces", func() {
+			BeforeEach(func() {
+				input = ""
+				prediction = "   Hello World   "
+			})
+
+			It("should trim spaces from the prediction", func() {
+				result = Finetune(testConfig, input, prediction)
+				Expect(result).To(Equal("Hello World"))
+			})
+		})
+
+		Context("when trimming suffixes", func() {
+			BeforeEach(func() {
+				input = ""
+				prediction = "Hello World."
+			})
+
+			It("should trim suffixes from the prediction", func() {
+				result = Finetune(testConfig, input, prediction)
+				Expect(result).To(Equal("Hello World"))
+			})
+		})
+	})
+})

core/config/backend_config.go

@@ -126,6 +126,7 @@ type LLMConfig struct {
 	Grammar         string   `yaml:"grammar"`
 	StopWords       []string `yaml:"stopwords"`
 	Cutstrings      []string `yaml:"cutstrings"`
+	ExtractRegex    []string `yaml:"extract_regex"`
 	TrimSpace       []string `yaml:"trimspace"`
 	TrimSuffix      []string `yaml:"trimsuffix"`
 

core/http/endpoints/openai/chat.go

@@ -68,9 +68,9 @@ func ChatEndpoint(cl *config.BackendConfigLoader, ml *model.ModelLoader, startup
 
 		textContentToReturn = functions.ParseTextContent(result, config.FunctionsConfig)
 		result = functions.CleanupLLMResult(result, config.FunctionsConfig)
-		results := functions.ParseFunctionCall(result, config.FunctionsConfig)
+		functionResults := functions.ParseFunctionCall(result, config.FunctionsConfig)
 		log.Debug().Msgf("Text content to return: %s", textContentToReturn)
-		noActionToRun := len(results) > 0 && results[0].Name == noAction || len(results) == 0
+		noActionToRun := len(functionResults) > 0 && functionResults[0].Name == noAction || len(functionResults) == 0
 
 		switch {
 		case noActionToRun:
@@ -83,7 +83,7 @@ func ChatEndpoint(cl *config.BackendConfigLoader, ml *model.ModelLoader, startup
 			}
 			responses <- initialMessage
 
-			result, err := handleQuestion(config, req, ml, startupOptions, results, result, prompt)
+			result, err := handleQuestion(config, req, ml, startupOptions, functionResults, result, prompt)
 			if err != nil {
 				log.Error().Err(err).Msg("error handling question")
 				return
@@ -105,7 +105,7 @@ func ChatEndpoint(cl *config.BackendConfigLoader, ml *model.ModelLoader, startup
 			responses <- resp
 
 		default:
-			for i, ss := range results {
+			for i, ss := range functionResults {
 				name, args := ss.Name, ss.Arguments
 
 				initialMessage := schema.OpenAIResponse{