Unmarshal: WIP

Signed-off-by: Alejandro Mery <amery@jpi.io>

parser/parser.go

@@ -9,16 +9,48 @@ import (
 
 // Parser parses a dosini-style document
 type Parser struct {
-	src *lexer.Lexer
+	src *lexer.Reader
+
+	OnSection func(pos lexer.Position, name, subname string, hasSubname bool) error
+	OnField   func(pos lexer.Position, key, value string) error
+	OnComment func(pos lexer.Position, comment string) error
+	OnError   func(pos lexer.Position, content string, err error) error
 }
 
-func (*Parser) init() error { return nil }
+func defaultOnSection(_ lexer.Position, _, _ string, _ bool) error { return nil }
+func defaultOnField(_ lexer.Position, _, _ string) error           { return nil }
+func defaultOnComment(_ lexer.Position, _ string) error            { return nil }
+
+func defaultOnError(pos lexer.Position, content string, err error) error {
+	return &lexer.Error{
+		Line:    pos.Line,
+		Column:  pos.Column,
+		Content: content,
+		Err:     err,
+	}
+}
+
+func (p *Parser) setDefaults() {
+	if p.OnSection == nil {
+		p.OnSection = defaultOnSection
+	}
+
+	if p.OnField == nil {
+		p.OnField = defaultOnField
+	}
+
+	if p.OnComment == nil {
+		p.OnComment = defaultOnComment
+	}
+
+	if p.OnError == nil {
+		p.OnError = defaultOnError
+	}
+}
 
 // Run parses the source
 func (p *Parser) Run() error {
-	if err := p.init(); err != nil {
-		return err
-	}
+	p.setDefaults()
 
 	return lexer.Run(p.initialState)
 }
@@ -31,6 +63,6 @@ func NewParser(r io.Reader) *Parser {
 	}
 
 	return &Parser{
-		src: lexer.NewLexerReader(r),
+		src: lexer.NewReader(r),
 	}
 }