refactor render

notes.txt

@@ -2,5 +2,4 @@ explain the immutability guarantee in the Go docs: for children yes, for childre
 recommendation is not to mutate children. Ofc, creatively breaking the rules is always well appreciated by the
 right audience
 test wrapped templates
-test empty block
 review which tags should be of type inline-children

render.go

@@ -51,6 +51,89 @@ func (r *renderer) getPrintf(tagName string) func(f string, a ...any) {
 	}
 }
 
+func (r *renderer) ensureWrapper() bool {
+	if _, ok := r.out.(*wrapper); ok {
+		return false
+	}
+
+	r.originalOut = r.out
+	r.out = newWrapper(r.originalOut, r.pwidth, r.currentIndent)
+	return true
+}
+
+func (r *renderer) clearWrapper() {
+	w, ok := r.out.(*wrapper)
+	if !ok {
+		return
+	}
+
+	if err := w.Flush(); err != nil {
+		r.err = err
+	}
+
+	r.out = r.originalOut
+}
+
+func (r *renderer) writeEscaped(s string) {
+	if r.err != nil {
+		return
+	}
+
+	ew := newEscapeWriter(r.out)
+	if _, r.err = ew.Write([]byte(s)); r.err != nil {
+		return
+	}
+
+	r.err = ew.Flush()
+}
+
+func (r *renderer) copyEscaped(rd io.Reader) {
+	if r.err != nil {
+		return
+	}
+
+	ew := newEscapeWriter(r.out)
+	if _, r.err = io.Copy(ew, rd); r.err != nil {
+		return
+	}
+
+	r.err = ew.Flush()
+}
+
+func (r *renderer) writeIndented(indent, s string) {
+	if r.err != nil {
+		return
+	}
+
+	iw := newIndentWriter(r.out, indent)
+	if _, r.err = iw.Write([]byte{'\n'}); r.err != nil {
+		return
+	}
+
+	if _, r.err = iw.Write([]byte(s)); r.err != nil {
+		return
+	}
+
+	r.err = iw.Flush()
+}
+
+func (r *renderer) copyIndented(indent string, rd io.Reader) {
+	if r.err != nil {
+		return
+	}
+
+	iw := newIndentWriter(r.out, indent)
+	if _, r.err = iw.Write([]byte{'\n'}); r.err != nil {
+		return
+	}
+
+	if _, r.err = io.Copy(iw, rd); r.err != nil {
+		return
+	}
+
+	r.err = iw.Flush()
+}
+
 func (r *renderer) renderAttributes(tagName string, a []Attributes) {
 	printf := r.getPrintf(tagName)
 	isDeclaration := strings.HasPrefix(tagName, "!")
@@ -89,31 +172,29 @@ func (r *renderer) renderUnindented(name string, rg renderGuide, a []Attributes,
 	}
 
 	for _, c := range children {
-		if ct, ok := c.(Tag); ok {
-			ct(r)
-			continue
-		}
-
 		if c == nil {
 			continue
 		}
 
-		if rd, ok := c.(io.Reader); ok {
+		rd, isReader := c.(io.Reader)
-			if rg.verbatim || rg.script {
+		if isReader && (rg.verbatim || rg.script) {
-				_, r.err = io.Copy(r.out, rd)
-				continue
-			}
-
-			ew := newEscapeWriter(r.out)
-			_, r.err = io.Copy(ew, rd)
 			if r.err == nil {
-				ew.Flush()
+				_, r.err = io.Copy(r.out, rd)
-				r.err = ew.err
 			}
 
 			continue
 		}
 
+		if isReader {
+			r.copyEscaped(rd)
+			continue
+		}
+
+		if ct, ok := c.(Tag); ok {
+			ct(r)
+			continue
+		}
+
 		s := fmt.Sprint(c)
 		if s == "" {
 			continue
@@ -124,42 +205,128 @@ func (r *renderer) renderUnindented(name string, rg renderGuide, a []Attributes,
 			continue
 		}
 
-		if r.err == nil {
+		r.writeEscaped(s)
-			ew := newEscapeWriter(r.out)
-			ew.Write([]byte(s))
-			ew.Flush()
-			r.err = ew.err
-		}
 	}
 
 	printf("</%s>", name)
 }
 
-func (r *renderer) ensureWrapper() bool {
+func (r *renderer) renderReaderChild(tagName string, rg renderGuide, block, lastBlock bool, rd io.Reader) bool {
-	if _, ok := r.out.(*wrapper); ok {
+	printf := r.getPrintf(tagName)
+	if rg.verbatim {
+		r.clearWrapper()
+		indent := r.currentIndent
+		if !block {
+			indent += r.indent.Indent
+		}
+
+		r.copyIndented(indent, rd)
 		return false
 	}
 
-	r.originalOut = r.out
+	if rg.script {
-	r.out = newWrapper(r.originalOut, r.pwidth, r.currentIndent)
+		r.clearWrapper()
-	return true
+		printf("\n")
+		if r.err == nil {
+			_, r.err = io.Copy(r.out, rd)
+		}
+
+		return false
+	}
+
+	if lastBlock {
+		printf("\n%s", r.currentIndent)
+	}
+
+	newWrapper := r.ensureWrapper()
+	r.copyEscaped(rd)
+	return newWrapper
 }
 
-func (r *renderer) clearWrapper() {
+func (r *renderer) renderChildTag(tagName string, block, lastBlock bool, ct Tag) (bool, bool) {
-	w, ok := r.out.(*wrapper)
+	printf := r.getPrintf(tagName)
-	if !ok {
+
+	var rgq renderGuidesQuery
+	ct(&rgq)
+	crg := mergeRenderingGuides(rgq.value)
+	if crg.inline {
+		if lastBlock {
+			printf("\n%s", r.currentIndent)
+		}
+
+		newWrapper := r.ensureWrapper()
+		ct(r)
+		return false, newWrapper
+	}
+
+	r.clearWrapper()
+	cr := new(renderer)
+	*cr = *r
+	if !block {
+		cr.currentIndent += cr.indent.Indent
+		cr.pwidth -= indentLen(cr.indent.Indent)
+		if cr.pwidth < cr.indent.MinPWidth {
+			cr.pwidth = cr.indent.MinPWidth
+		}
+	}
+
+	printf("\n%s", cr.currentIndent)
+	ct(cr)
+	if cr.err != nil {
+		r.err = cr.err
+	}
+
+	return true, false
+}
+
+func (r *renderer) renderVerbatimChild(block bool, c any) {
+	s := fmt.Sprint(c)
+	if s == "" {
 		return
 	}
 
-	if err := w.Flush(); err != nil {
+	r.clearWrapper()
-		r.err = err
+	indent := r.currentIndent
+	if !block {
+		indent += r.indent.Indent
 	}
 
-	r.out = r.originalOut
+	r.writeIndented(indent, s)
 }
 
-func (r *renderer) renderInline(name string, rg renderGuide, a []Attributes, children []any) {
+func (r *renderer) renderChildScript(tagName string, c any) {
+	s := fmt.Sprint(c)
+	if s == "" {
+		return
+	}
+
+	r.clearWrapper()
+	printf := r.getPrintf(tagName)
+	printf("\n%s", s)
+}
+
+func (r *renderer) renderChildContent(tagName string, lastBlock bool, c any) bool {
+	s := fmt.Sprint(c)
+	if s == "" {
+		return false
+	}
+
+	if lastBlock {
+		printf := r.getPrintf(tagName)
+		printf("\n%s", r.currentIndent)
+	}
+
 	newWrapper := r.ensureWrapper()
+	r.writeEscaped(s)
+	return newWrapper
+}
+
+func (r *renderer) renderIndented(name string, rg renderGuide, a []Attributes, children []any) {
+	var newWrapper bool
+	if rg.inline || rg.inlineChildren {
+		newWrapper = r.ensureWrapper()
+	}
+
 	printf := r.getPrintf(name)
 	printf("<%s", name)
 	r.renderAttributes(name, a)
@@ -172,333 +339,87 @@ func (r *renderer) renderInline(name string, rg renderGuide, a []Attributes, chi
 		return
 	}
 
-	var lastBlock bool
+	if len(children) == 0 {
-	for _, c := range children {
+		printf("</%s>", name)
-		rd, isReader := c.(io.Reader)
+		if newWrapper {
-		if isReader && rg.verbatim {
 			r.clearWrapper()
-			if r.err == nil {
-				iw := newIndentWriter(r.out, r.currentIndent+r.indent.Indent)
-				iw.Write([]byte{'\n'})
-				_, r.err = io.Copy(iw, rd)
-				if r.err == nil {
-					iw.Flush()
-					r.err = iw.err
-				}
-			}
-
-			lastBlock = true
-			continue
 		}
 
-		if isReader && rg.script {
+		return
-			r.clearWrapper()
-			printf("\n")
-			_, r.err = io.Copy(r.out, rd)
-			lastBlock = true
-			continue
-		}
-
-		if isReader {
-			if lastBlock {
-				printf("\n%s", r.currentIndent)
-			}
-
-			if r.ensureWrapper() {
-				newWrapper = true
-			}
-
-			if r.err == nil {
-				ew := newEscapeWriter(r.out)
-				_, r.err = io.Copy(ew, rd)
-				if r.err == nil {
-					ew.Flush()
-					r.err = ew.err
-				}
-			}
-
-			lastBlock = false
-			continue
-		}
-
-		ct, isTag := c.(Tag)
-		if !isTag && rg.verbatim {
-			if c == nil {
-				continue
-			}
-
-			s := fmt.Sprint(c)
-			if s == "" {
-				continue
-			}
-
-			r.clearWrapper()
-			if r.err == nil {
-				iw := newIndentWriter(r.out, r.currentIndent+r.indent.Indent)
-				iw.Write([]byte{'\n'})
-				iw.Write([]byte(s))
-				iw.Flush()
-				r.err = iw.err
-			}
-
-			lastBlock = true
-			continue
-		}
-
-		if !isTag && rg.script {
-			if c == nil {
-				continue
-			}
-
-			s := fmt.Sprint(c)
-			if s == "" {
-				continue
-			}
-
-			r.clearWrapper()
-			printf("\n%s", s)
-			lastBlock = true
-			continue
-		}
-
-		if !isTag {
-			if c == nil {
-				continue
-			}
-
-			s := fmt.Sprint(c)
-			if s == "" {
-				continue
-			}
-
-			if lastBlock {
-				printf("\n%s", r.currentIndent)
-			}
-
-			if r.ensureWrapper() {
-				newWrapper = true
-			}
-
-			if r.err == nil {
-				ew := newEscapeWriter(r.out)
-				ew.Write([]byte(s))
-				ew.Flush()
-				r.err = ew.err
-			}
-
-			lastBlock = false
-			continue
-		}
-
-		var rgq renderGuidesQuery
-		ct(&rgq)
-		crg := mergeRenderingGuides(rgq.value)
-		if crg.inline {
-			if lastBlock {
-				printf("\n%s", r.currentIndent)
-			}
-
-			if r.ensureWrapper() {
-				newWrapper = true
-			}
-
-			ct(r)
-			lastBlock = false
-			continue
-		}
-
-		r.clearWrapper()
-		cr := new(renderer)
-		*cr = *r
-		cr.currentIndent += cr.indent.Indent
-		cr.pwidth -= indentLen(cr.indent.Indent)
-		if cr.pwidth < cr.indent.MinPWidth {
-			cr.pwidth = cr.indent.MinPWidth
-		}
-
-		printf("\n%s", cr.currentIndent)
-		ct(cr)
-		if cr.err != nil {
-			r.err = cr.err
-		}
-
-		lastBlock = true
 	}
 
-	if lastBlock {
+	block := !rg.inline && !rg.inlineChildren
+	lastBlock := block
+	originalIndent, originalWidth := r.currentIndent, r.pwidth
+	if block {
+		r.currentIndent += r.indent.Indent
+		r.pwidth -= indentLen(r.indent.Indent)
+		if r.pwidth < r.indent.MinPWidth {
+			r.pwidth = r.indent.MinPWidth
+		}
+	}
+
+	for _, c := range children {
+		if c == nil {
+			continue
+		}
+
+		if ct, isTag := c.(Tag); isTag {
+			var nw bool
+			lastBlock, nw = r.renderChildTag(name, block, lastBlock, ct)
+			if nw {
+				newWrapper = true
+			}
+
+			continue
+		}
+
+		if rd, isReader := c.(io.Reader); isReader {
+			if r.renderReaderChild(name, rg, block, lastBlock, rd) {
+				newWrapper = true
+			}
+
+			lastBlock = rg.verbatim || rg.script
+			continue
+		}
+
+		if rg.verbatim {
+			r.renderVerbatimChild(block, c)
+			lastBlock = true
+			continue
+		}
+
+		if rg.script {
+			r.renderChildScript(name, c)
+			lastBlock = true
+			continue
+		}
+
+		if r.renderChildContent(name, lastBlock, c) {
+			newWrapper = true
+		}
+
+		lastBlock = false
+	}
+
+	if block {
+		r.currentIndent, r.pwidth = originalIndent, originalWidth
+	}
+
+	if block {
+		r.clearWrapper()
+	}
+
+	if lastBlock || block {
 		printf("\n%s", r.currentIndent)
 	}
 
 	printf("</%s>", name)
-	if newWrapper {
+	if newWrapper && !block {
 		r.clearWrapper()
 	}
 }
 
-func (r *renderer) renderBlock(name string, rg renderGuide, a []Attributes, children []any) {
-	printf := r.getPrintf(name)
-	printf("<%s", name)
-	r.renderAttributes(name, a)
-	printf(">")
-	if rg.void {
-		return
-	}
-
-	if len(children) == 0 {
-		printf("</%s>", name)
-		return
-	}
-
-	lastBlock := true
-	originalIndent, originalWidth := r.currentIndent, r.pwidth
-	r.currentIndent += r.indent.Indent
-	r.pwidth -= indentLen(r.indent.Indent)
-	if r.pwidth < r.indent.MinPWidth {
-		r.pwidth = r.indent.MinPWidth
-	}
-
-	for _, c := range children {
-		rd, isReader := c.(io.Reader)
-		if isReader && rg.verbatim {
-			r.clearWrapper()
-			if r.err == nil {
-				iw := newIndentWriter(r.out, r.currentIndent)
-				iw.Write([]byte{'\n'})
-				_, r.err = io.Copy(iw, rd)
-				if r.err == nil {
-					iw.Flush()
-					r.err = iw.err
-				}
-			}
-
-			lastBlock = true
-			continue
-		}
-
-		if isReader && rg.script {
-			r.clearWrapper()
-			printf("\n")
-			_, r.err = io.Copy(r.out, rd)
-			lastBlock = true
-			continue
-		}
-
-		if isReader {
-			if lastBlock {
-				printf("\n%s", r.currentIndent)
-			}
-
-			r.ensureWrapper()
-			if r.err == nil {
-				ew := newEscapeWriter(r.out)
-				_, r.err = io.Copy(ew, rd)
-				if r.err == nil {
-					ew.Flush()
-					r.err = ew.err
-				}
-			}
-
-			lastBlock = false
-			continue
-		}
-
-		ct, isTag := c.(Tag)
-		if !isTag && rg.verbatim {
-			if c == nil {
-				continue
-			}
-
-			s := fmt.Sprint(c)
-			if s == "" {
-				continue
-			}
-
-			r.clearWrapper()
-			if r.err == nil {
-				iw := newIndentWriter(r.out, r.currentIndent)
-				iw.Write([]byte{'\n'})
-				iw.Write([]byte(s))
-				iw.Flush()
-				r.err = iw.err
-			}
-
-			lastBlock = true
-			continue
-		}
-
-		if !isTag && rg.script {
-			if c == nil {
-				continue
-			}
-
-			s := fmt.Sprint(c)
-			if s == "" {
-				continue
-			}
-
-			r.clearWrapper()
-			printf("\n%s", s)
-			lastBlock = true
-			continue
-		}
-
-		if !isTag {
-			if c == nil {
-				continue
-			}
-
-			s := fmt.Sprint(c)
-			if s == "" {
-				continue
-			}
-
-			if lastBlock {
-				printf("\n%s", r.currentIndent)
-			}
-
-			r.ensureWrapper()
-			if r.err == nil {
-				ew := newEscapeWriter(r.out)
-				ew.Write([]byte(s))
-				ew.Flush()
-				r.err = ew.err
-			}
-
-			lastBlock = false
-			continue
-		}
-
-		var rgq renderGuidesQuery
-		ct(&rgq)
-		crg := mergeRenderingGuides(rgq.value)
-		if crg.inline {
-			if lastBlock {
-				printf("\n%s", r.currentIndent)
-			}
-
-			r.ensureWrapper()
-			ct(r)
-			lastBlock = false
-			continue
-		}
-
-		r.clearWrapper()
-		cr := new(renderer)
-		*cr = *r
-		printf("\n%s", cr.currentIndent)
-		ct(cr)
-		if cr.err != nil {
-			r.err = cr.err
-		}
-
-		lastBlock = true
-	}
-
-	r.clearWrapper()
-	r.currentIndent, r.pwidth = originalIndent, originalWidth
-	printf("\n%s</%s>", r.currentIndent, name)
-}
-
 func (r *renderer) render(name string, children []any) {
 	if r.err != nil {
 		return
@@ -511,10 +432,5 @@ func (r *renderer) render(name string, children []any) {
 		return
 	}
 
-	if rg.inline || rg.inlineChildren {
+	r.renderIndented(name, rg, a, c)
-		r.renderInline(name, rg, a, c)
-		return
-	}
-
-	r.renderBlock(name, rg, a, c)
 }