Extract source walk part of scanner

1 files changed, 28 insertions, 91 deletions

diff --git a/pkg/lang/scanner/scanner.go b/pkg/lang/scanner/scanner.go
index 19e3462..2991083 100644
--- a/pkg/lang/scanner/scanner.go
+++ b/pkg/lang/scanner/scanner.go
@@ -1,29 +1,24 @@
 package scanner
 
 import (
-	"bufio"
-	"errors"
 	"io"
 	"jinx/pkg/lang/scanner/token"
+	"jinx/pkg/libs/source"
 	"strconv"
 	"strings"
 	"unicode"
 )
 
 type Scanner struct {
-	source *bufio.Reader
-	row    int
-	col    int
+	src    source.Walker
 	indent int
 
 	finished bool
 }
 
-func New(source io.Reader) *Scanner {
+func New(src io.Reader) *Scanner {
 	return &Scanner{
-		source:   bufio.NewReader(source),
-		row:      0,
-		col:      0,
+		src:      *source.NewWalker(src),
 		indent:   0,
 		finished: false,
 	}
@@ -62,14 +57,14 @@ func (s *Scanner) scanToken() (token.Token, error) {
 		return token.New(token.EOL, firstNewline, nil), nil
 	}
 
-	c, eof, err := s.peek()
+	c, eof, err := s.src.Peek()
 	if err != nil {
 		return token.Token{}, err
 	}
 
 	if eof {
 		s.finished = true
-		return token.Simple(token.EOF, s.loc()), nil
+		return token.Simple(token.EOF, s.src.Loc()), nil
 	}
 
 	if c == '"' {
@@ -80,8 +75,8 @@ func (s *Scanner) scanToken() (token.Token, error) {
 		return s.scanNumber()
 	}
 
-	loc := s.loc()
-	c, _, err = s.next()
+	loc := s.src.Loc()
+	c, _, err = s.src.Next()
 	if err != nil {
 		return token.Token{}, err
 	}
@@ -91,7 +86,7 @@ func (s *Scanner) scanToken() (token.Token, error) {
 	case '\n':
 		kind = token.EOL
 	case '=':
-		if cont, err := s.consume('='); cont && err == nil {
+		if cont, err := s.src.Consume('='); cont && err == nil {
 			kind = token.Eq
 		} else if cont && err != nil {
 			kind = token.Assign
@@ -110,7 +105,7 @@ func (s *Scanner) scanToken() (token.Token, error) {
 		kind = token.Percent
 
 	case '<':
-		if cont, err := s.consume('='); cont && err == nil {
+		if cont, err := s.src.Consume('='); cont && err == nil {
 			kind = token.Lte
 		} else if cont && err != nil {
 			kind = token.Lt
@@ -118,7 +113,7 @@ func (s *Scanner) scanToken() (token.Token, error) {
 			return token.Token{}, err
 		}
 	case '>':
-		if cont, err := s.consume('='); cont && err == nil {
+		if cont, err := s.src.Consume('='); cont && err == nil {
 			kind = token.Gte
 		} else if cont && err != nil {
 			kind = token.Gt
@@ -126,7 +121,7 @@ func (s *Scanner) scanToken() (token.Token, error) {
 			return token.Token{}, err
 		}
 	case '!':
-		if cont, err := s.consume('='); cont && err == nil {
+		if cont, err := s.src.Consume('='); cont && err == nil {
 			kind = token.Neq
 		} else if cont && err != nil {
 			kind = token.Bang
@@ -162,15 +157,15 @@ func (s *Scanner) scanToken() (token.Token, error) {
 }
 
 func (s *Scanner) scanString() (token.Token, error) {
-	loc := s.loc()
-	if _, err := s.consume('"'); err != nil {
+	loc := s.src.Loc()
+	if _, err := s.src.Consume('"'); err != nil {
 		return token.Token{}, err
 	}
 
 	var buf strings.Builder
 
 	for {
-		c, eof, err := s.next()
+		c, eof, err := s.src.Next()
 		if err != nil {
 			return token.Token{}, err
 		}
@@ -190,12 +185,12 @@ func (s *Scanner) scanString() (token.Token, error) {
 }
 
 func (s *Scanner) scanIdentifierOrKeyword() (token.Token, error) {
-	loc := s.loc()
+	loc := s.src.Loc()
 
 	var buf strings.Builder
 
 	for {
-		c, eof, err := s.peek()
+		c, eof, err := s.src.Peek()
 		if err != nil {
 			return token.Token{}, err
 		}
@@ -204,7 +199,7 @@ func (s *Scanner) scanIdentifierOrKeyword() (token.Token, error) {
 			break
 		}
 
-		if _, _, err = s.next(); err != nil {
+		if _, _, err = s.src.Next(); err != nil {
 			return token.Token{}, err
 		}
 
@@ -270,12 +265,12 @@ func (s *Scanner) scanIdentifierOrKeyword() (token.Token, error) {
 }
 
 func (s *Scanner) scanNumber() (token.Token, error) {
-	loc := s.loc()
+	loc := s.src.Loc()
 
 	var buf strings.Builder
 
 	for {
-		c, eof, err := s.peek()
+		c, eof, err := s.src.Peek()
 		if err != nil {
 			return token.Token{}, err
 		}
@@ -284,7 +279,7 @@ func (s *Scanner) scanNumber() (token.Token, error) {
 			break
 		}
 
-		if _, _, err = s.next(); err != nil {
+		if _, _, err = s.src.Next(); err != nil {
 			return token.Token{}, err
 		}
 
@@ -299,18 +294,18 @@ func (s *Scanner) scanNumber() (token.Token, error) {
 	return token.New(token.Int, loc, num), nil
 }
 
-func (s *Scanner) skipWhitespace() (bool, token.Loc, error) {
+func (s *Scanner) skipWhitespace() (bool, source.Loc, error) {
 	hadNewline := false
-	firstNewline := token.Loc{}
+	firstNewline := source.Loc{}
 
 	for {
-		c, eof, err := s.peek()
+		c, eof, err := s.src.Peek()
 		if err != nil {
-			return false, token.Loc{}, err
+			return false, source.Loc{}, err
 		}
 
 		if c == '\n' && !hadNewline {
-			firstNewline = s.loc()
+			firstNewline = s.src.Loc()
 			hadNewline = true
 		}
 
@@ -318,68 +313,10 @@ func (s *Scanner) skipWhitespace() (bool, token.Loc, error) {
 			break
 		}
 
-		if _, _, err = s.next(); err != nil {
-			return false, token.Loc{}, err
+		if _, _, err = s.src.Next(); err != nil {
+			return false, source.Loc{}, err
 		}
 	}
 
 	return hadNewline, firstNewline, nil
 }
-
-func (s *Scanner) loc() token.Loc {
-	return token.Loc{
-		Row: s.row,
-		Col: s.col,
-	}
-}
-
-func (s *Scanner) next() (rune, bool, error) {
-	r, _, err := s.source.ReadRune()
-	if err != nil {
-		if errors.Is(err, io.EOF) {
-			return 0, true, nil
-		}
-
-		return 0, false, err
-	}
-
-	if r == '\n' {
-		s.row++
-		s.col = 0
-	} else {
-		s.col++
-	}
-
-	return r, false, nil
-}
-
-func (s *Scanner) consume(want rune) (bool, error) {
-	c, _, err := s.next()
-	if err != nil {
-		return false, err
-	}
-
-	if c != want {
-		return true, ErrUnexpectedChar{
-			Expected: want,
-			Actual:   c,
-		}
-	}
-
-	return true, nil
-}
-
-func (s *Scanner) peek() (rune, bool, error) {
-	r, _, err := s.source.ReadRune()
-	defer s.source.UnreadRune()
-
-	if err != nil {
-		if errors.Is(err, io.EOF) {
-			return 0, true, nil
-		}
-
-		return 0, false, err
-	}
-
-	return r, false, nil
-}