rename templates to template

templates/template.go → template/template.go

-package templates
+package template
 
 import (
 	"bytes"
@@ -7,9 +7,14 @@ import (
 	"errors"
 	"io"
 	"math"
+	"slices"
+	"strings"
 	"sync"
+	"text/template"
+	"text/template/parse"
 
 	"github.com/agnivade/levenshtein"
+	"golang.org/x/exp/maps"
 )
 
 //go:embed index.json
@@ -18,8 +23,8 @@ var indexBytes []byte
 //go:embed *.gotmpl
 var templatesFS embed.FS
 
-var templatesOnce = sync.OnceValues(func() ([]*Template, error) {
-	var templates []*Template
+var templatesOnce = sync.OnceValues(func() ([]*named, error) {
+	var templates []*named
 	if err := json.Unmarshal(indexBytes, &templates); err != nil {
 		return nil, err
 	}
@@ -37,23 +42,23 @@ var templatesOnce = sync.OnceValues(func() ([]*Template, error) {
 	return templates, nil
 })
 
-type Template struct {
+type named struct {
 	Name     string `json:"name"`
 	Template string `json:"template"`
 	Bytes    []byte
 }
 
-func (t Template) Reader() io.Reader {
+func (t named) Reader() io.Reader {
 	return bytes.NewReader(t.Bytes)
 }
 
-func NamedTemplate(s string) (*Template, error) {
+func Named(s string) (*named, error) {
 	templates, err := templatesOnce()
 	if err != nil {
 		return nil, err
 	}
 
-	var template *Template
+	var template *named
 	score := math.MaxInt
 	for _, t := range templates {
 		if s := levenshtein.ComputeDistance(s, t.Template); s < score {
@@ -68,3 +73,86 @@ func NamedTemplate(s string) (*Template, error) {
 
 	return nil, errors.New("no matching template found")
 }
+
+type Template struct {
+	*template.Template
+	raw string
+}
+
+func (t *Template) String() string {
+	return t.raw
+}
+
+var DefaultTemplate, _ = Parse("{{ .Prompt }}")
+
+func Parse(s string) (*Template, error) {
+	t, err := template.New("").Option("missingkey=zero").Parse(s)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Template{Template: t, raw: s}, nil
+}
+
+func (t *Template) Vars() []string {
+	var vars []string
+	for _, n := range t.Tree.Root.Nodes {
+		vars = append(vars, parseNode(n)...)
+	}
+
+	set := make(map[string]struct{})
+	for _, n := range vars {
+		set[strings.ToLower(n)] = struct{}{}
+	}
+
+	vars = maps.Keys(set)
+	slices.Sort(vars)
+	return vars
+}
+
+func parseNode(n parse.Node) []string {
+	switch n := n.(type) {
+	case *parse.ActionNode:
+		return parseNode(n.Pipe)
+	case *parse.IfNode:
+		names := parseNode(n.Pipe)
+		names = append(names, parseNode(n.List)...)
+		if n.ElseList != nil {
+			names = append(names, parseNode(n.ElseList)...)
+		}
+		return names
+	case *parse.RangeNode:
+		names := parseNode(n.Pipe)
+		names = append(names, parseNode(n.List)...)
+		if n.ElseList != nil {
+			names = append(names, parseNode(n.ElseList)...)
+		}
+		return names
+	case *parse.WithNode:
+		names := parseNode(n.Pipe)
+		names = append(names, parseNode(n.List)...)
+		if n.ElseList != nil {
+			names = append(names, parseNode(n.ElseList)...)
+		}
+		return names
+	case *parse.PipeNode:
+		var names []string
+		for _, c := range n.Cmds {
+			for _, a := range c.Args {
+				names = append(names, parseNode(a)...)
+			}
+		}
+		return names
+	case *parse.ListNode:
+		var names []string
+		for _, n := range n.Nodes {
+			names = append(names, parseNode(n)...)
+		}
+
+		return names
+	case *parse.FieldNode:
+		return n.Ident
+	}
+
+	return nil
+}

templates/template_test.go → template/template_test.go

-package templates
+package template
 
 import (
 	"bufio"
@@ -7,13 +7,14 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"slices"
 	"testing"
 	"text/template"
 
 	"github.com/ollama/ollama/llm"
 )
 
-func TestKVChatTemplate(t *testing.T) {
+func TestNamed(t *testing.T) {
 	f, err := os.Open(filepath.Join("testdata", "templates.jsonl"))
 	if err != nil {
 		t.Fatal(err)
@@ -31,7 +32,7 @@ func TestKVChatTemplate(t *testing.T) {
 			t.Run(k, func(t *testing.T) {
 				kv := llm.KV{"tokenizer.chat_template": v}
 				s := kv.ChatTemplate()
-				r, err := NamedTemplate(s)
+				r, err := Named(s)
 				if err != nil {
 					t.Fatal(err)
 				}
@@ -57,3 +58,32 @@ func TestKVChatTemplate(t *testing.T) {
 		}
 	}
 }
+
+func TestParse(t *testing.T) {
+	cases := []struct {
+		template     string
+		capabilities []string
+	}{
+		{"{{ .Prompt }}", []string{"prompt"}},
+		{"{{ .System }} {{ .Prompt }}", []string{"prompt", "system"}},
+		{"{{ .System }} {{ .Prompt }} {{ .Response }}", []string{"prompt", "response", "system"}},
+		{"{{ with .Tools }}{{ . }}{{ end }} {{ .System }} {{ .Prompt }}", []string{"prompt", "system", "tools"}},
+		{"{{ range .Messages }}{{ .Role }} {{ .Content }}{{ end }}", []string{"content", "messages", "role"}},
+		{"{{ range .Messages }}{{ if eq .Role \"system\" }}SYSTEM: {{ .Content }}{{ else if eq .Role \"user\" }}USER: {{ .Content }}{{ else if eq .Role \"assistant\" }}ASSISTANT: {{ .Content }}{{ end }}{{ end }}", []string{"content", "messages", "role"}},
+		{"{{ .Prompt }} {{ .Suffix }}", []string{"prompt", "suffix"}},
+	}
+
+	for _, tt := range cases {
+		t.Run("", func(t *testing.T) {
+			tmpl, err := Parse(tt.template)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			vars := tmpl.Vars()
+			if !slices.Equal(tt.capabilities, vars) {
+				t.Errorf("expected %v, got %v", tt.capabilities, vars)
+			}
+		})
+	}
+}