Add namespaces and include tag, improve whitespace handling

README.md

@@ -30,16 +30,15 @@ Salix's syntax is similar to Leaf and (in my opinion at least), it's much more f
 ### API Usage
 
 ```go
-t, err := salix.New().
-    WithVarMap(vars).
-    WithFuncMap(funcs).
-    WithEscapeHTML(true).
-    ParseFile("example.salix.txt")
+t, err := salix.New().ParseFile("example.salix.txt")
 if err != nil {
   panic(err)
 }
 
-err = t.Execute(os.Stdout)
+err = t.WithVarMap(vars).
+    WithFuncMap(funcs).
+    WithEscapeHTML(true).
+    Execute(os.Stdout)
 if err != nil {
   panic(err)
 }

examples/readme/main.go

@@ -56,15 +56,14 @@ func main() {
 		"page":  Page{Title: "Users"},
 	}
 
-	t, err := salix.New().
-		WithVarMap(vars).
-		WithEscapeHTML(true).
-		ParseString("readme.salix.html", tmpl)
+	t, err := salix.New().ParseString("readme.salix.html", tmpl)
 	if err != nil {
 		log.Fatalln(err)
 	}
 
-	err = t.Execute(os.Stdout)
+	err = t.WithVarMap(vars).
+		WithEscapeHTML(true).
+		Execute(os.Stdout)
 	if err != nil {
 		log.Fatalln(err)
 	}

examples/replybot/main.go

@@ -23,13 +23,12 @@ func main() {
 	}
 
 	t, err := salix.New().
-		WithVarMap(vars).
 		ParseString("replybot.salix.txt", tmpl)
 	if err != nil {
 		log.Fatalln(err)
 	}
 
-	err = t.Execute(os.Stdout)
+	err = t.WithVarMap(vars).Execute(os.Stdout)
 	if err != nil {
 		log.Fatalln(err)
 	}

examples/replybot/replybot.salix.txt

@@ -1,4 +1,5 @@
 #if(len(matches) > 1):Imgur links were#else:An Imgur link was#!if detected in your #(type). Here are links to the same #if(len(matches) > 1):locations#else:location#!if on alternative frontends that protect your privacy.
+
 #for(i, match in matches):
 #if(len(matches) > 1):Link #(i+1):#!if
 - [imgur.artemislena.eu](https://imgur.artemislena.eu/#(match[1]))

for_tag.go

@@ -9,7 +9,7 @@ import (
 
 var ErrForTagInvalidArgs = errors.New("invalid arguments in for tag")
 
-// forTag represents a #if tag within a Salix template
+// forTag represents a #for tag within a Salix template
 type forTag struct{}
 
 func (ft forTag) Run(tc *TagContext, block, args []ast.Node) error {

funcs.go

@@ -1,31 +0,0 @@
-package salix
-
-import (
-	"reflect"
-	"strings"
-)
-
-var defaultFuncs = map[string]any{
-	"len":        tmplLen,
-	"toUpper":    strings.ToUpper,
-	"toLower":    strings.ToLower,
-	"hasPrefix":  strings.HasPrefix,
-	"trimPrefix": strings.TrimPrefix,
-	"hasSuffix":  strings.HasSuffix,
-	"trimSuffix": strings.TrimSuffix,
-	"trimSpace":  strings.TrimSpace,
-	"equalFold":  strings.EqualFold,
-	"count":      strings.Count,
-	"split":      strings.Split,
-	"join":       strings.Join,
-}
-
-func tmplLen(v any) int {
-	val := reflect.ValueOf(v)
-	switch val.Kind() {
-	case reflect.Array, reflect.Slice, reflect.String, reflect.Map:
-		return val.Len()
-	default:
-		return -1
-	}
-}

include_tag.go

@@ -0,0 +1,38 @@
+package salix
+
+import (
+	"errors"
+
+	"go.elara.ws/salix/internal/ast"
+)
+
+var (
+	ErrIncludeInvalidArgs = errors.New("include expects one string argument")
+	ErrNoSuchTemplate     = errors.New("no such template")
+)
+
+// forTag represents an #include tag within a Salix template
+type includeTag struct{}
+
+func (it includeTag) Run(tc *TagContext, block, args []ast.Node) error {
+	if len(args) != 1 {
+		return ErrIncludeInvalidArgs
+	}
+
+	val, err := tc.GetValue(args[0], nil)
+	if err != nil {
+		return err
+	}
+
+	name, ok := val.(string)
+	if !ok {
+		return ErrIncludeInvalidArgs
+	}
+
+	tmpl, ok := tc.t.ns.GetTemplate(name)
+	if !ok {
+		return ErrNoSuchTemplate
+	}
+
+	return tc.Execute(tmpl.ast, nil)
+}

namespace.go

@@ -0,0 +1,78 @@
+package salix
+
+import (
+	"reflect"
+	"sync"
+)
+
+// Namespace represents a collection of templates that can include each other
+type Namespace struct {
+	mu    sync.Mutex
+	tmpls map[string]*Template
+	vars  map[string]reflect.Value
+	tags  map[string]Tag
+}
+
+// New returns a new template namespace
+func New() *Namespace {
+	return &Namespace{
+		tmpls: map[string]*Template{},
+		vars:  map[string]reflect.Value{},
+		tags:  map[string]Tag{},
+	}
+}
+
+// WithVarMap sets the namespace's variable map to m
+func (n *Namespace) WithVarMap(m map[string]any) *Namespace {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	n.vars = map[string]reflect.Value{}
+	if m != nil {
+		for k, v := range m {
+			n.vars[k] = reflect.ValueOf(v)
+		}
+	}
+
+	return n
+}
+
+// WithTagMap sets the namespace's tag map to m
+func (n *Namespace) WithTagMap(m map[string]Tag) *Namespace {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	if m != nil {
+		n.tags = m
+	} else {
+		n.tags = map[string]Tag{}
+	}
+
+	return n
+}
+
+// GetTemplate tries to get a template from the namespace's template map.
+// If it finds the template, it returns the template and true. If it
+// doesn't find it, it returns nil and false.
+func (n *Namespace) GetTemplate(name string) (*Template, bool) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	t, ok := n.tmpls[name]
+	return t, ok
+}
+
+// getVar tries to get a variable from the namespace's variable map
+func (n *Namespace) getVar(name string) (reflect.Value, bool) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	v, ok := n.vars[name]
+	return v, ok
+}
+
+// getTag tries to get a tag from the namespace's tag map
+func (n *Namespace) getTag(name string) (Tag, bool) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	t, ok := n.tags[name]
+	return t, ok
+}

parse.go

@@ -3,36 +3,52 @@ package salix
 import (
 	"bytes"
 	"io"
+	"io/fs"
 	"os"
+	"reflect"
 	"strings"
 
 	"go.elara.ws/salix/internal/ast"
 	"go.elara.ws/salix/internal/parser"
 )
 
-// Parse parses a salix template from r. If the reader has a Name method
-// that returns a string, that will be used as the filename.
-func (t *Template) Parse(r io.Reader) (*Template, error) {
-	fname := "<input>"
-	if r, ok := r.(interface{ Name() string }); ok {
-		fname = r.Name()
-	}
-	return t.ParseWithFilename(fname, r)
+// NamedReader is a reader with a name
+type NamedReader interface {
+	io.Reader
+	Name() string
 }
 
-// ParseWithFilename parses a salix template from r, using the given filename.
-func (t *Template) ParseWithFilename(filename string, r io.Reader) (*Template, error) {
-	astVal, err := parser.ParseReader(filename, r)
+// Parse parses a salix template from a NamedReader, which is an io.Reader
+// with a Name method that returns a string. os.File implements NamedReader.
+func (n *Namespace) Parse(r NamedReader) (*Template, error) {
+	return n.ParseWithName(r.Name(), r)
+}
+
+// ParseWithFilename parses a salix template from r, using the given name.
+func (n *Namespace) ParseWithName(name string, r io.Reader) (*Template, error) {
+	astVal, err := parser.ParseReader(name, r)
 	if err != nil {
 		return nil, err
 	}
-	t.file = filename
-	t.ast = astVal.([]ast.Node)
+
+	t := &Template{
+		ns:   n,
+		name: name,
+		ast:  astVal.([]ast.Node),
+		tags: map[string]Tag{},
+		vars: map[string]reflect.Value{},
+	}
+
+	performWhitespaceMutations(t.ast)
+
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	n.tmpls[name] = t
 	return t, nil
 }
 
-// ParseFile parses the file at path as a salix template
-func (t *Template) ParseFile(path string) (*Template, error) {
+// ParseFile parses the file at path as a salix template. It uses the path as the name.
+func (t *Namespace) ParseFile(path string) (*Template, error) {
 	fl, err := os.Open(path)
 	if err != nil {
 		return nil, err
@@ -41,12 +57,98 @@ func (t *Template) ParseFile(path string) (*Template, error) {
 	return t.Parse(fl)
 }
 
+// ParseFile parses a file at the given path in a filesystem. It uses the path as the name.
+func (t *Namespace) ParseFS(fsys fs.FS, path string) (*Template, error) {
+	fl, err := fsys.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer fl.Close()
+	return t.ParseWithName(path, fl)
+}
+
 // ParseString parses a string using the given filename.
-func (t *Template) ParseString(filename, tmpl string) (*Template, error) {
-	return t.ParseWithFilename(filename, strings.NewReader(tmpl))
+func (t *Namespace) ParseString(filename, tmpl string) (*Template, error) {
+	return t.ParseWithName(filename, strings.NewReader(tmpl))
 }
 
 // ParseString parses bytes using the given filename.
-func (t *Template) ParseBytes(filename string, tmpl []byte) (*Template, error) {
-	return t.ParseWithFilename(filename, bytes.NewReader(tmpl))
+func (t *Namespace) ParseBytes(filename string, tmpl []byte) (*Template, error) {
+	return t.ParseWithName(filename, bytes.NewReader(tmpl))
+}
+
+// performWhitespaceMutations mutates nodes in the AST to remove
+// whitespace where it isn't needed.
+func performWhitespaceMutations(nodes []ast.Node) {
+	// lastTag keeps track of which line the
+	// last tag was found on, so that if an end
+	// tag was found on the same line, we know it's inline
+	// and we don't need to handle its whitespace.
+	lastTag := 0
+
+	for i := 0; i < len(nodes); i++ {
+		switch node := nodes[i].(type) {
+		case ast.Tag:
+			// If the node has no body, it's an inline tag,
+			// so we don't need to handle any whitespace around it.
+			if !node.HasBody {
+				continue
+			}
+			handleWhitespace(nodes, i)
+			lastTag = node.Position.Line
+		case ast.EndTag:
+			if lastTag != node.Position.Line {
+				handleWhitespace(nodes, i)
+			}
+		}
+	}
+}
+
+// handleWhitespace mutates nodes above and below tags and end tags
+// to remove the unneeded whitespace around them.
+func handleWhitespace(nodes []ast.Node, i int) {
+	lastIndex := len(nodes) - 1
+
+	var prevNode ast.Text
+	var nextNode ast.Text
+
+	if i != 0 {
+		if node, ok := nodes[i-1].(ast.Text); ok {
+			prevNode = node
+		}
+	}
+
+	if i != lastIndex {
+		if node, ok := nodes[i+1].(ast.Text); ok {
+			nextNode = node
+		}
+	}
+
+	if prevNode.Data != nil && bytes.Contains(nextNode.Data, []byte{'\n'}) {
+		prevNode.Data = trimWhitespaceSuffix(prevNode.Data)
+		nodes[i-1] = prevNode
+	}
+
+	if nextNode.Data != nil {
+		nextNode.Data = bytes.TrimPrefix(nextNode.Data, []byte{'\n'})
+		nodes[i+1] = nextNode
+	}
+}
+
+// trimWhitespaceSuffix removes everything up to and including the first newline
+// it finds, starting from the end of the slice. If a non-whitespace character is
+// encountered before a newline, the data is returned unmodified.
+func trimWhitespaceSuffix(data []byte) []byte {
+	// Start from the end of the slice
+	for i := len(data) - 1; i >= 0; i-- {
+		if data[i] == '\n' {
+			// If a newline is found, return the slice without the newline and anything after
+			return data[:i+1]
+		} else if data[i] != ' ' && data[i] != '\t' && data[i] != '\r' {
+			// If a non-whitespace character is found, return the original slice
+			return data
+		}
+	}
+	// If no newline or non-whitespace character is found, return the original slice
+	return data
 }

salix.go

@@ -1,12 +1,10 @@
 package salix
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"html"
 	"io"
-	"maps"
 	"reflect"
 
 	"go.elara.ws/salix/internal/ast"
@@ -31,87 +29,77 @@ var (
 	ErrFuncSecondReturnType = errors.New("the second return value of a template function must be an error")
 )
 
+// HTML represents unescaped HTML strings
 type HTML string
 
 // Template represents a Salix template
 type Template struct {
-	file string
+	ns   *Namespace
+	name string
 	ast  []ast.Node
 
 	escapeHTML bool
 
-	tags  map[string]Tag
-	funcs map[string]reflect.Value
-	vars  map[string]reflect.Value
+	tags map[string]Tag
+	vars map[string]reflect.Value
 }
 
-// New creates a new base template with the default
-// tags and functions added.
-func New() *Template {
-	t := &Template{
-		funcs: map[string]reflect.Value{},
-		vars:  map[string]reflect.Value{},
-		tags:  map[string]Tag{},
-	}
-	return t.WithTagMap(defaultTags).WithFuncMap(defaultFuncs)
-}
-
-// Clone returns a shallow clone of a template.
-func (t *Template) Clone() *Template {
-	return &Template{
-		file: t.file,
+// WithVarMap returns a copy of the template with its variable map set to m.
+func (t *Template) WithVarMap(m map[string]any) *Template {
+	newTmpl := &Template{
+		ns:   t.ns,
+		name: t.name,
 		ast:  t.ast,
 
 		escapeHTML: t.escapeHTML,
 
-		tags:  maps.Clone(t.tags),
-		funcs: maps.Clone(t.funcs),
-		vars:  maps.Clone(t.vars),
+		tags: t.tags,
+		vars: map[string]reflect.Value{},
 	}
-}
 
-// WithFuncMap adds all the functions in m to the template's
-// global function map. If a function with the given name already
-// exists, it will be overwritten.
-func (t *Template) WithFuncMap(m map[string]any) *Template {
 	if m != nil {
-		for name, fn := range m {
-			t.funcs[name] = reflect.ValueOf(fn)
+		for k, v := range m {
+			newTmpl.vars[k] = reflect.ValueOf(v)
 		}
 	}
-	return t
+
+	return newTmpl
 }
 
-// WithVarMap adds all the variables in m to the template's
-// global variable map. If a variable with the given name already
-// exists, it will be overwritten.
-func (t *Template) WithVarMap(m map[string]any) *Template {
-	if m != nil {
-		for name, val := range m {
-			t.vars[name] = reflect.ValueOf(val)
-		}
-	}
-	return t
-}
-
-// WithTagMap adds all the tags in m to the template's
-// global tag map. If a tag with the given name already
-// exists, it will be overwritten.
+// WithTagMap returns a copy of the template with its tag map set to m.
 func (t *Template) WithTagMap(m map[string]Tag) *Template {
-	if m != nil {
-		for name, tag := range m {
-			t.tags[name] = tag
-		}
+	// Make sure the tag map is never nil to avoid panics
+	if m == nil {
+		m = map[string]Tag{}
+	}
+
+	return &Template{
+		ns:   t.ns,
+		name: t.name,
+		ast:  t.ast,
+
+		escapeHTML: t.escapeHTML,
+
+		tags: m,
+		vars: t.vars,
 	}
-	return t
 }
 
-// WithEscapeHTML enables or disables HTML escaping.
+// WithEscapeHTML returns a copy of the template with HTML escaping enabled or disabled.
 // The HTML escaping functionality is NOT context-aware.
-// Using the HTML type allows you to get around the escaping.
+// Using the HTML type allows you to get around the escaping if needed.
 func (t *Template) WithEscapeHTML(b bool) *Template {
 	t.escapeHTML = true
-	return t
+	return &Template{
+		ns:   t.ns,
+		name: t.name,
+		ast:  t.ast,
+
+		escapeHTML: b,
+
+		tags: t.tags,
+		vars: t.vars,
+	}
 }
 
 // Execute executes a parsed template and writes
@@ -181,15 +169,10 @@ func (t *Template) getBlock(nodes []ast.Node, offset, startLine int, name string
 			if node.Name.Value == name {
 				tagAmount--
 			}
-			// Once tagAmount is zero (all the tags of the same name)
-			// have been closed with an end tag, we can handle our newlines
-			// and return the nodes we've accumulated.
+			// Once tagAmount is zero (all the tags of the same name
+			// have been closed with an end tag), we can return
+			// the nodes we've accumulated.
 			if tagAmount == 0 {
-				// If the end tag is on the same line as the start tag,
-				// we don't need to remove any newlines.
-				if node.Position.Line != startLine {
-					t.handleNewlines(nodes, i)
-				}
 				return out
 			} else {
 				out = append(out, node)
@@ -207,7 +190,11 @@ func (t *Template) getValue(node ast.Node, local map[string]any) (any, error) {
 	case ast.Value:
 		return t.unwrapASTValue(node, local)
 	case ast.Ident:
-		return t.getVar(node, local)
+		val, err := t.getVar(node, local)
+		if err != nil {
+			return nil, err
+		}
+		return val.Interface(), nil
 	case ast.String:
 		return node.Value, nil
 	case ast.Float:
@@ -254,56 +241,58 @@ func (t *Template) unwrapASTValue(node ast.Value, local map[string]any) (any, er
 // getVar tries to get a variable from the local map. If it's not found,
 // it'll try the global variable map. If it doesn't exist in either map,
 // it will return an error.
-func (t *Template) getVar(id ast.Ident, local map[string]any) (any, error) {
+func (t *Template) getVar(id ast.Ident, local map[string]any) (reflect.Value, error) {
 	if local != nil {
 		v, ok := local[id.Value]
 		if ok {
-			return v, nil
+			return reflect.ValueOf(v), nil
 		}
 	}
 
 	v, ok := t.vars[id.Value]
-	if !ok {
-		return nil, t.posError(id, "%w: %s", ErrNoSuchVar, id.Value)
+	if ok {
+		return v, nil
 	}
 
-	return v.Interface(), nil
+	v, ok = t.ns.getVar(id.Value)
+	if ok {
+		return v, nil
+	}
+
+	v, ok = globalVars[id.Value]
+	if ok {
+		return v, nil
+	}
+
+	return reflect.Value{}, t.posError(id, "%w: %s", ErrNoSuchVar, id.Value)
 }
 
-// handleNewlines removes newlines above and below the given index
-// in the nodes slice.
-func (t *Template) handleNewlines(nodes []ast.Node, i int) {
-	if i != 0 {
-		if node, ok := nodes[i-1].(ast.Text); ok {
-			ni := bytes.LastIndexByte(node.Data, '\n')
-			if ni != -1 {
-				node.Data = node.Data[:ni]
-			}
-			nodes[i-1] = node
-		}
+func (t *Template) getTag(name string) (Tag, bool) {
+	tag, ok := t.tags[name]
+	if ok {
+		return tag, true
 	}
 
-	lastIndex := len(nodes) - 1
-	if i != lastIndex {
-		if node, ok := nodes[i+1].(ast.Text); ok {
-			ni := bytes.IndexByte(node.Data, '\n')
-			if ni != -1 {
-				node.Data = node.Data[ni:]
-			}
-			nodes[i+1] = node
-		}
+	tag, ok = t.ns.getTag(name)
+	if ok {
+		return tag, true
 	}
+
+	tag, ok = globalTags[name]
+	if ok {
+		return tag, true
+	}
+
+	return nil, false
 }
 
 // execTag executes a tag
 func (t *Template) execTag(node ast.Tag, w io.Writer, nodes []ast.Node, i int, local map[string]any) (newOffset int, err error) {
-	tag, ok := t.tags[node.Name.Value]
+	tag, ok := t.getTag(node.Name.Value)
 	if !ok {
 		return 0, t.posError(node, "%w: %s", ErrNoSuchTag, node.Name.Value)
 	}
 
-	t.handleNewlines(nodes, i)
-
 	var block []ast.Node
 	if node.HasBody {
 		block = t.getBlock(nodes, i+1, node.Position.Line, node.Name.Value)
@@ -322,8 +311,8 @@ func (t *Template) execTag(node ast.Tag, w io.Writer, nodes []ast.Node, i int, l
 
 // execFuncCall executes a function call
 func (t *Template) execFuncCall(fc ast.FuncCall, local map[string]any) (any, error) {
-	fn, ok := t.funcs[fc.Name.Value]
-	if !ok {
+	fn, err := t.getVar(fc.Name, local)
+	if err != nil {
 		return nil, t.posError(fc, "%w: %s", ErrNoSuchFunc, fc.Name.Value)
 	}
 	return t.execFunc(fn, fc, fc.Params, local)
@@ -439,7 +428,7 @@ func (t *Template) execFunc(fn reflect.Value, node ast.Node, args []ast.Node, lo
 }
 
 func (t *Template) posError(n ast.Node, format string, v ...any) error {
-	return ast.PosError(n, t.file, format, v...)
+	return ast.PosError(n, t.name, format, v...)
 }
 
 func validateFunc(t reflect.Type) error {

tags.go

@@ -6,25 +6,30 @@ import (
 	"go.elara.ws/salix/internal/ast"
 )
 
+// Tag represents a tag in a Salix template
 type Tag interface {
 	Run(tc *TagContext, block, args []ast.Node) error
 }
 
-var defaultTags = map[string]Tag{
-	"if":  ifTag{},
-	"for": forTag{},
+var globalTags = map[string]Tag{
+	"if":      ifTag{},
+	"for":     forTag{},
+	"include": includeTag{},
 }
 
+// TagContext is passed to Tag implementations to allow them to control the interpreter
 type TagContext struct {
 	w     io.Writer
 	t     *Template
 	local map[string]any
 }
 
+// Execute runs the interpreter on the given AST nodes, with the given local variables.
 func (tc *TagContext) Execute(nodes []ast.Node, local map[string]any) error {
 	return tc.t.execute(tc.w, nodes, mergeMap(tc.local, local))
 }
 
+// GetValue evaluates the given AST node using the given local variables.
 func (tc *TagContext) GetValue(node ast.Node, local map[string]any) (any, error) {
 	return tc.t.getValue(node, mergeMap(tc.local, local))
 }

vars.go

@@ -0,0 +1,31 @@
+package salix
+
+import (
+	"reflect"
+	"strings"
+)
+
+var globalVars = map[string]reflect.Value{
+	"len":        reflect.ValueOf(tmplLen),
+	"toUpper":    reflect.ValueOf(strings.ToUpper),
+	"toLower":    reflect.ValueOf(strings.ToLower),
+	"hasPrefix":  reflect.ValueOf(strings.HasPrefix),
+	"trimPrefix": reflect.ValueOf(strings.TrimPrefix),
+	"hasSuffix":  reflect.ValueOf(strings.HasSuffix),
+	"trimSuffix": reflect.ValueOf(strings.TrimSuffix),
+	"trimSpace":  reflect.ValueOf(strings.TrimSpace),
+	"equalFold":  reflect.ValueOf(strings.EqualFold),
+	"count":      reflect.ValueOf(strings.Count),
+	"split":      reflect.ValueOf(strings.Split),
+	"join":       reflect.ValueOf(strings.Join),
+}
+
+func tmplLen(v any) int {
+	val := reflect.ValueOf(v)
+	switch val.Kind() {
+	case reflect.Array, reflect.Slice, reflect.String, reflect.Map:
+		return val.Len()
+	default:
+		return -1
+	}
+}