feat: Add pointer support

evaluator/prefix.go

@@ -37,6 +37,22 @@ func evalPrefixExpression(operator string, right object.Object, line int) object
 		return evalMinusPrefixOperatorExpression(right, line)
 	case "+":
 		return evalPlusPrefixOperatorExpression(right, line)
+	case "*":
+		if right == nil {
+			return newError("Mstari %d: huwezi kufikia thamani ya pointer isiyo na kitu (nil)", line)
+		}
+		if p, ok := right.(*object.Pointer); ok {
+			if p.Ref == nil {
+				return newError("Mstari %d: pointer haina kitu (nil)", line)
+			}
+			return p.Ref
+		}
+		return newError("Mstari %d: huwezi kufikia thamani ya kitu ambacho si pointer", line)
+	case "&":
+		if right == nil {
+			return newError("Mstari %d: huwezi kupata anwani ya kitu kisicho na thamani (nil)", line)
+		}
+		return &object.Pointer{Ref: right}
 	default:
 		return newError("Mstari %d: Operesheni Haieleweki: %s%s", line, operator, right.Type())
 	}

examples/pointer.nr

@@ -0,0 +1,5 @@
+fanya x = 42 * 2
+fanya p = &x
+andika(p)
+andika("POINTER is",p)
+andika("VALUE is",*p)

lexer/lexer.go

@@ -153,6 +153,8 @@ func (l *Lexer) NextToken() token.Token {
 			ch := l.ch
 			l.readChar()
 			tok = token.Token{Type: token.AND, Literal: string(ch) + string(l.ch), Line: l.line}
+		} else {
+			tok = newToken(token.AMPERSAND, l.line, l.ch)
 		}
 	case rune('|'):
 		if l.peekChar() == rune('|') {

object/object.go

@@ -27,6 +27,7 @@ const (
 	BYTE_OBJ         = "BYTE"
 	PACKAGE_OBJ      = "PAKEJI"
 	INSTANCE         = "PAKEJI"
+	POINTER_OBJ      = "POINTER"
 	AT               = "@"
 )
 

object/pointer.go

@@ -0,0 +1,20 @@
+package object
+
+import (
+	"fmt"
+)
+
+type Pointer struct {
+	Ref Object
+}
+
+func (p *Pointer) Type() ObjectType {
+	return POINTER_OBJ
+}
+
+func (p *Pointer) Inspect() string {
+	if p.Ref == nil {
+		return "Pointer(anwani=nil, thamani=nil)"
+	}
+	return fmt.Sprintf("Pointer(anwani=%p, thamani=%s)", p.Ref, p.Ref.Inspect())
+}

parser/parser.go

@@ -113,6 +113,8 @@ func New(l *lexer.Lexer) *Parser {
 	p.registerPrefix(token.IMPORT, p.parseImport)
 	p.registerPrefix(token.PACKAGE, p.parsePackage)
 	p.registerPrefix(token.AT, p.parseAt)
+	p.registerPrefix(token.AMPERSAND, p.parsePrefixExpression)
+	p.registerPrefix(token.ASTERISK, p.parsePrefixExpression)
 
 	p.infixParseFns = make(map[token.TokenType]infixParseFn)
 	p.registerInfix(token.AND, p.parseInfixExpression)

token/token.go

@@ -26,6 +26,7 @@ const (
 	MINUS           = "-"
 	BANG            = "!"
 	ASTERISK        = "*"
+	AMPERSAND       = "&"
 	POW             = "**"
 	SLASH           = "/"
 	MODULUS         = "%"