Refactored code generator, tracks indentation, no error checking

internal/zig/zig.go

@@ -6,123 +6,127 @@ import (
 )
 
 type formatter struct {
-	io.Writer
+	w      io.Writer
+	line   int // 1-based
+	col    int // 1-based, reset to 1 after newline
+	indent int // indentation level
 }
 
-func (f *formatter) WriteString(s string) (n int, err error) {
-	return f.Write([]byte(s))
+const indentStr = "    " // 4 spaces per indent
+
+func (f *formatter) Writef(format string, a ...any) {
+	s := fmt.Sprintf(format, a...)
+	for i, r := range s {
+		if r == '\n' {
+			f.line++
+			f.col = 1
+			// If next character is not a newline and not end, and not a closing brace, write indentation
+			if i+1 < len(s) && s[i+1] != '\n' && s[i+1] != '}' {
+				f.writeIndent()
+			}
+		} else {
+			if f.col == 0 {
+				f.col = 1
+			} else {
+				f.col++
+			}
+		}
+	}
+	if _, err := f.w.Write([]byte(s)); err != nil {
+		panic(err)
+	}
 }
 
-func (f *formatter) Writef(format string, a ...any) (err error) {
-	_, err = fmt.Fprintf(f, format, a...)
-	return err
+func (f *formatter) writeIndent() {
+	for i := 0; i < f.indent; i++ {
+		if _, err := f.w.Write([]byte(indentStr)); err != nil {
+			panic(err)
+		}
+		f.col += len(indentStr)
+	}
 }
 
-func Write(w io.Writer, root *Root) error {
-	f := &formatter{Writer: w}
+func Write(w io.Writer, root *Root) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if e, ok := r.(error); ok {
+				err = e
+			} else {
+				panic(r)
+			}
+		}
+	}()
+	f := &formatter{w: w, line: 1, col: 1, indent: 0}
 
 	if root.ContainerDocComment != "" {
-		if err := f.Writef("//! %s\n\n", root.ContainerDocComment); err != nil {
-			return err
-		}
+		f.Writef("//! %s\n\n", root.ContainerDocComment)
 	}
 	for _, member := range root.ContainerMembers {
 		// Only handle Decl for now (fields not needed for hello world)
 		if member.Decl != nil {
-			if err := writeDecl(f, member.Decl); err != nil {
-				return err
-			}
+			writeDecl(f, member.Decl)
 		}
 	}
 	return nil
 }
 
-func writeDecl(f *formatter, decl Decl) error {
+func writeDecl(f *formatter, decl Decl) {
 	switch fn := decl.(type) {
 	case *FnDecl:
-		if err := f.Writef("fn %s(", fn.Name); err != nil {
-			return err
-		}
-		if err := writeParams(f, fn.Params); err != nil {
-			return err
-		}
-		if _, err := f.WriteString(") "); err != nil {
-			return err
-		}
-		if err := writeTypeExpr(f, fn.ReturnType); err != nil {
-			return err
-		}
-		if err := writeBlock(f, fn.Body); err != nil {
-			return err
-		}
+		f.Writef("fn %s(", fn.Name)
+		writeParams(f, fn.Params)
+		f.Writef(") ")
+		writeTypeExpr(f, fn.ReturnType)
+		writeBlock(f, fn.Body)
 	}
-	return nil
 }
 
-func writeParams(f *formatter, params []*ParamDecl) error {
+func writeParams(f *formatter, params []*ParamDecl) {
 	for i, param := range params {
 		if i > 0 {
-			if _, err := f.WriteString(", "); err != nil {
-				return err
-			}
+			f.Writef(", ")
 		}
 		if param.Name != "" {
-			if _, err := f.WriteString(param.Name); err != nil {
-				return err
-			}
-			if _, err := f.WriteString(": "); err != nil {
-				return err
-			}
-		}
-		if err := writeTypeExpr(f, param.Type); err != nil {
-			return err
+			f.Writef("%s: ", param.Name)
 		}
+		writeTypeExpr(f, param.Type)
 	}
-	return nil
 }
 
-func writeTypeExpr(f *formatter, typ TypeExpr) error {
+func writeTypeExpr(f *formatter, typ TypeExpr) {
 	switch t := typ.(type) {
 	case *Identifier:
-		_, err := f.WriteString(t.Name)
-		return err
+		f.Writef("%s", t.Name)
 	case nil:
-		return nil
+		// nothing
 	default:
-		// fallback: print as string
-		_, err := f.WriteString(fmt.Sprintf("%v", t))
-		return err
+		f.Writef("%v", t)
 	}
 }
 
-func writeBlock(f *formatter, block *Block) error {
+func writeBlock(f *formatter, block *Block) {
 	if block == nil {
-		_, err := f.WriteString(";")
-		return err
+		f.Writef(";")
+		return
 	}
-	if _, err := f.WriteString(" {\n"); err != nil {
-		return err
-	}
-	for _, stmt := range block.Stmts {
-		if err := writeStmt(f, stmt); err != nil {
-			return err
-		}
-		if _, err := f.WriteString("\n"); err != nil {
-			return err
+	f.Writef(" {\n")
+	f.indent++
+	for i, stmt := range block.Stmts {
+		f.writeIndent()
+		writeStmt(f, stmt)
+		if i < len(block.Stmts)-1 {
+			f.Writef("\n")
 		}
 	}
-	if _, err := f.WriteString("}\n"); err != nil {
-		return err
-	}
-	return nil
+	f.indent--
+	f.Writef("\n")
+	f.writeIndent()
+	f.Writef("}\n")
 }
 
-func writeStmt(f *formatter, stmt Stmt) error {
+func writeStmt(f *formatter, stmt Stmt) {
 	switch stmt.(type) {
 	case *ReturnStmt:
-		if _, err := f.WriteString("return;"); err != nil {
-			return err
-		}
+		f.Writef("return;")
 	}
-	return nil
 }

internal/zig/zig_test.go

@@ -20,7 +20,7 @@ func TestHelloWorld(t *testing.T) {
 	expected := `//! Hello, world!
 
 fn main() void {
-return;
+    return;
 }
 `