decoder [WIP]

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

basic/error.go

@@ -4,19 +4,28 @@ import (
 	"errors"
 
 	"asciigoat.org/core/lexer"
-	"asciigoat.org/ini/parser"
 )
 
 var (
 	errInvalidToken = errors.New("invalid token")
 )
 
+func newError(pos lexer.Position, content, hint string, err error) *lexer.Error {
+	return &lexer.Error{
+		Line:    pos.Line,
+		Column:  pos.Column,
+		Content: content,
+		Hint:    hint,
+		Err:     err,
+	}
+}
+
 func newErrInvalidToken(t *token) *lexer.Error {
-	return parser.NewError(t.pos, t.value, "", errInvalidToken)
+	return newError(t.pos, t.value, "", errInvalidToken)
 }
 
 func (dec *decoder) OnError(pos lexer.Position, content string, err error) error {
-	err = parser.NewError(pos, content, "", err)
+	err = newError(pos, content, "", err)
 	dec.executeFinal()
 	return err
 }

decoder.go

@@ -0,0 +1,83 @@
+package ini
+
+import (
+	"bytes"
+	"io"
+	"strings"
+
+	"asciigoat.org/core"
+	"asciigoat.org/core/reflective"
+	"asciigoat.org/ini/parser"
+)
+
+const (
+	decPrefixLiteral = "ini: Decode"
+)
+
+var (
+	decINIPrefix = decPrefixLiteral[0:3]
+	decDecPrefix = decPrefixLiteral[5:]
+)
+
+// Decoder ...
+type Decoder struct {
+	io.Closer
+
+	out   *reflective.Reflection
+	p     *parser.Parser
+	queue []*token
+}
+
+// Decode ...
+func (dec *Decoder) Decode(v any) error {
+	defer dec.Close()
+
+	r, err := reflective.New(v)
+	switch e := err.(type) {
+	case *reflective.InvalidUnmarshalError:
+		// customize error
+		e.Prefix = decINIPrefix
+		e.Method = decDecPrefix
+	case *reflective.UnmarshalTypeError:
+		// customize error
+		e.Prefix = decPrefixLiteral
+	case nil:
+		// good reflection. Go!
+		dec.out = r
+		err = dec.p.Run()
+	}
+
+	return err
+}
+
+// NewDecoder creates a Decoder using the provided [io.Reader]
+// as source
+func NewDecoder(r io.Reader) *Decoder {
+	rc := core.NewReadCloser(r)
+	switch {
+	case rc == nil:
+		return nil
+	default:
+		dec := &Decoder{
+			p:      parser.NewParser(rc),
+			Closer: rc,
+		}
+
+		// callbacks
+		dec.p.OnToken = dec.parserOnToken
+		dec.p.OnError = dec.parserOnError
+
+		return dec
+	}
+}
+
+// NewDecoderBytes creates a Decoder using the provided bytes array
+// as source
+func NewDecoderBytes(b []byte) *Decoder {
+	return NewDecoder(bytes.NewReader(b))
+}
+
+// NewDecoderString creates a Decoder over a provided string of data
+func NewDecoderString(s string) *Decoder {
+	return NewDecoder(strings.NewReader(s))
+}

decoder_error.go

@@ -0,0 +1,32 @@
+package ini
+
+import (
+	"errors"
+	"log"
+
+	"asciigoat.org/core/lexer"
+)
+
+var (
+	errInvalidToken = errors.New("invalid token")
+)
+
+func newError(pos lexer.Position, content, hint string, err error) *lexer.Error {
+	return &lexer.Error{
+		Line:    pos.Line,
+		Column:  pos.Column,
+		Content: content,
+		Hint:    hint,
+		Err:     err,
+	}
+}
+func (*Decoder) newErrInvalidToken(t *token) *lexer.Error {
+	return newError(t.pos, t.value, "", errInvalidToken)
+}
+
+// parserOnError is the callback for lexer errors
+func (*Decoder) parserOnError(pos lexer.Position, content string, err error) error {
+	log.Printf("%s: %s %s: %q: %v", "ini", pos, "error", content, err)
+
+	return newError(pos, content, "", err)
+}

decoder_token.go

@@ -0,0 +1,144 @@
+package ini
+
+import (
+	"fmt"
+	"log"
+
+	"asciigoat.org/core/lexer"
+	"asciigoat.org/ini/parser"
+)
+
+type token struct {
+	pos   lexer.Position
+	typ   parser.TokenType
+	value string
+}
+
+func (t token) String() string {
+	return fmt.Sprintf("%s %s: %q", t.pos, t.typ, t.value)
+}
+
+// queueValue extracts the value of element on the queue if the type matches.
+func (dec *Decoder) queueValue(idx int, typ parser.TokenType) (string, bool) {
+	switch {
+	case idx < 0 || idx >= len(dec.queue):
+		// out of range
+		return "", false
+	case dec.queue[idx].typ != typ:
+		// wrong type
+		return "", false
+	default:
+		// match
+		return dec.queue[idx].value, true
+	}
+}
+
+// queueReset removes all tokens from the queue
+func (dec *Decoder) queueReset() {
+	dec.queue = dec.queue[:0]
+}
+
+// queueType tells if the specified element on the queue is of the required type.
+func (dec *Decoder) queueType(idx int, typ parser.TokenType) bool {
+	_, ok := dec.queueValue(idx, typ)
+	return ok
+}
+
+// queueDepth confirms the current depth of the queue
+func (dec *Decoder) queueDepth(depth int) bool {
+	return len(dec.queue) == depth
+}
+
+// queueDepthType confirms the current depth of the queue and the type of the last
+// element.
+func (dec *Decoder) queueDepthType(depth int, typ parser.TokenType) bool {
+	if dec.queueDepth(depth) {
+		return dec.queueType(depth-1, typ)
+	}
+	return false
+}
+
+// typeOK tells if a token of the specified type is acceptable
+// at this time.
+func (dec *Decoder) typeOK(typ parser.TokenType) bool {
+	switch typ {
+	case parser.TokenSectionStart:
+		return dec.queueDepth(0)
+	case parser.TokenSectionName:
+		return dec.queueDepthType(1, parser.TokenSectionStart)
+	case parser.TokenSectionSubname:
+		return dec.queueDepthType(2, parser.TokenSectionName)
+	case parser.TokenSectionEnd:
+		return dec.queueType(1, parser.TokenSectionName)
+	case parser.TokenFieldKey:
+		return dec.queueDepth(0)
+	case parser.TokenFieldValue:
+		return dec.queueDepthType(1, parser.TokenFieldKey)
+	case parser.TokenComment:
+		panic("unreachable")
+	default:
+		return false
+	}
+}
+
+// execute is called after each acceptable token is appended to the queue
+func (dec *Decoder) execute() error {
+	if l := len(dec.queue); l > 0 {
+		// based on the type of the last element
+		switch dec.queue[l-1].typ {
+		case parser.TokenSectionEnd:
+			name1, _ := dec.queueValue(1, parser.TokenSectionName)
+			name2, ok2 := dec.queueValue(2, parser.TokenSectionSubname)
+			defer dec.queueReset()
+
+			return dec.executeSection(name1, name2, ok2)
+		case parser.TokenFieldValue:
+			key, _ := dec.queueValue(0, parser.TokenFieldKey)
+			value, _ := dec.queueValue(1, parser.TokenFieldValue)
+			defer dec.queueReset()
+
+			return dec.executeField(key, value)
+		}
+	}
+
+	return nil
+}
+
+// revive:disable:flag-parameter
+
+func (*Decoder) executeSection(key, id string, hasID bool) error {
+	// revive:enable:flag-parameter
+
+	if hasID {
+		log.Printf("%s: %s%s[%q]: %q", "ini", "", "section", key, id)
+	} else {
+		log.Printf("%s: %s%s[%q]", "ini", "", "section", key)
+	}
+
+	return nil
+}
+
+func (*Decoder) executeField(key, value string) error {
+	log.Printf("%s: %s%s[%q]: %q", "ini", "  ", "field", key, value)
+	return nil
+}
+
+// parserOnToken is the callback from the parser
+func (dec *Decoder) parserOnToken(pos lexer.Position, typ parser.TokenType, value string) error {
+	var err error
+
+	t := &token{pos, typ, value}
+	switch {
+	case typ == parser.TokenComment:
+		// ignore comments
+	case dec.typeOK(typ):
+		// acceptable token
+		dec.queue = append(dec.queue, t)
+		err = dec.execute()
+	default:
+		// unacceptable
+		err = dec.newErrInvalidToken(t)
+	}
+
+	return err
+}

go.mod

@@ -2,8 +2,13 @@ module asciigoat.org/ini
 
 go 1.19
 
+replace (
+	asciigoat.org/core => ../core
+	darvaza.org/core => ../../darvaza.org/core
+)
+
 require (
-	asciigoat.org/core v0.3.9
+	asciigoat.org/core v0.3.7
 	github.com/mgechev/revive v1.3.3
 	golang.org/x/tools v0.12.0
 )

go.sum

@@ -1,5 +1,3 @@
-asciigoat.org/core v0.3.9 h1:hgDDz4ecm3ZvehX++m8A/IzAt+B5oDPiRtxatzfUHPQ=
-asciigoat.org/core v0.3.9/go.mod h1:CAaHwyw8MpAq4a1MYtN2dxJrsK+hmIdW50OndaQZYPI=
 github.com/BurntSushi/toml v1.3.2 h1:o7IhLm0Msx3BaB+n3Ag7L8EVlByGnpq14C4YWiu/gL8=
 github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/chavacava/garif v0.1.0 h1:2JHa3hbYf5D9dsgseMKAmc/MZ109otzgNFk5s87H9Pc=

parser/error.go

@@ -1,27 +0,0 @@
-package parser
-
-import (
-	"asciigoat.org/core/lexer"
-)
-
-// NewError creates a lexer.Error using a lexer.Position
-func NewError(pos lexer.Position, content, hint string, err error) *lexer.Error {
-	return &lexer.Error{
-		Line:    pos.Line,
-		Column:  pos.Column,
-		Content: content,
-		Hint:    hint,
-		Err:     err,
-	}
-}
-
-// ErrPlusPosition returns a copy of the given [lexer.Error]
-// offsetting the Line/Column information.
-func ErrPlusPosition(pos lexer.Position, e *lexer.Error) *lexer.Error {
-	pos.Add(lexer.Position{
-		Line:   e.Line,
-		Column: e.Column,
-	})
-
-	return NewError(pos, e.Content, e.Hint, e.Err)
-}

parser/lexer_runes.go

@@ -43,11 +43,6 @@ var (
 	IsCommentStart = lexer.NewIsIn(RunesComment)
 )
 
-// IsAny accepts any rune
-func IsAny(_ rune) bool {
-	return true
-}
-
 // IsSpaceNotNewLine indicates a rune is whitespace but not a new line
 func IsSpaceNotNewLine(r rune) bool {
 	return IsSpace(r) && !IsNewLine(r)

parser/parser.go

@@ -31,7 +31,13 @@ func defaultOnToken(pos lexer.Position, typ TokenType, value string) error {
 func defaultOnError(pos lexer.Position, content string, err error) error {
 	log.Printf("%s:%v:%v: %q: %s", "error", pos.Line, pos.Column, content, err)
 
-	return NewError(pos, content, "", err)
+	return lexer.Error{
+		Line:   pos.Line,
+		Column: pos.Column,
+
+		Content: content,
+		Err:     err,
+	}
 }
 
 func (p *Parser) setDefaults() {

parser/text.go

@@ -39,10 +39,9 @@ func (p *TextParser) InitString(s string) {
 
 // Discard shadows [lexer.Reader]'s, and takes in consideration
 // new lines on the discarded data when moving the position
-func (p *TextParser) Discard() {
+func (*TextParser) Discard() {
-	s := p.Reader.Emit()
+	// TODO: consider new lines
-	l := GetPositionalLength(s)
+	panic("not implemented")
-	p.pos.Add(l)
 }
 
 // Emit returns the accepted text, its position, and
@@ -50,8 +49,8 @@ func (p *TextParser) Discard() {
 func (p *TextParser) Emit() (lexer.Position, string) {
 	pos := p.pos
 	s := p.Reader.Emit()
-	l := GetPositionalLength(s)
+	// TODO: consider new lines
-	p.pos.Add(l)
+	p.pos.StepN(len(s))
 
 	return pos, s
 }

parser/text_position.go

@@ -1,38 +0,0 @@
-package parser
-
-import (
-	"io"
-
-	"asciigoat.org/core/lexer"
-)
-
-type positionLengthParser struct {
-	TextParser
-
-	lexer.Position
-}
-
-func (p *positionLengthParser) lexStart() (lexer.StateFn, error) {
-	for {
-		switch {
-		case p.AcceptNewLine():
-			p.Position.StepLine()
-		case p.Accept(IsAny):
-			p.Position.StepN(1)
-		default:
-			return nil, io.EOF
-		}
-	}
-}
-
-// GetPositionalLength calculates the [lexer.Position] at
-// the end of a text.
-func GetPositionalLength(s string) lexer.Position {
-	var p positionLengthParser
-	if s == "" {
-		p.InitString(s)
-
-		_ = lexer.Run(p.lexStart)
-	}
-	return p.Position
-}