add scanner.Positions

scanner/position.go

@@ -1,7 +1,63 @@
 package scanner
 
+import (
+	"github.com/brettlangdon/gython/token"
+)
+
 type Position struct {
 	Line   int
 	Column int
 	Char   rune
 }
+
+type Positions struct {
+	positions []*Position
+}
+
+func NewPositions() *Positions {
+	return &Positions{
+		positions: make([]*Position, 0),
+	}
+}
+
+func (positions *Positions) Append(pos *Position) {
+	positions.positions = append(positions.positions, pos)
+}
+
+func (positions *Positions) StartingLine() int {
+	return positions.positions[0].Line
+}
+
+func (positions *Positions) EndingLine() int {
+	last := len(positions.positions) - 1
+	return positions.positions[last].Line
+}
+
+func (positions *Positions) StartingColumn() int {
+	return positions.positions[0].Column
+}
+
+func (positions *Positions) EndingColumn() int {
+	last := len(positions.positions) - 1
+	return positions.positions[last].Column
+}
+
+func (positions *Positions) String() string {
+	literal := ""
+	for _, pos := range positions.positions {
+		literal += string(pos.Char)
+	}
+
+	return literal
+}
+
+func (positions *Positions) AsToken(id token.TokenID) *token.Token {
+	return &token.Token{
+		ID:          id,
+		LineStart:   positions.StartingLine(),
+		ColumnStart: positions.StartingColumn(),
+		LineEnd:     positions.EndingLine(),
+		ColumnEnd:   positions.EndingColumn(),
+		Literal:     positions.String(),
+	}
+}