Added match statements to the parser

Added match statements to the parser

entity/misc.go

@@ -76,7 +76,8 @@ func (this *Member) String () string {
 
 // Case represents a match case.
 type Case struct {
-	Declaration Declaration
+	Position    errors.Position
+	Declaration *Declaration
 	Expression
 }
 func (this *Case) String () string {

parser/fspl/expression.go

@@ -116,6 +116,7 @@ func (this *treeParser) parseExpressionRootIdent () (entity.Expression, error) {
 	case "true", "false": return this.parseLiteralBoolean ()
 	case "nil":           return this.parseLiteralNil()
 	case "if":            return this.parseIfElse()
+	case "match":         return this.parseMatch()
 	case "loop":          return this.parseLoop()
 	default:
 		this.Next()
@@ -563,6 +564,47 @@ func (this *treeParser) parseIfElse () (*entity.IfElse, error) {
 	return ifElse, nil
 }
 
+func (this *treeParser) parseMatch () (*entity.Match, error) {
+	err := this.ExpectValue(lexer.Ident, "match")
+	if err != nil { return nil, err }
+	match := &entity.Match {
+		Position: this.Pos(),
+	}
+
+	err = this.ExpectNextDesc(descriptionExpression, startTokensExpression...)
+	if err != nil { return nil, err }
+	match.Value, err = this.parseExpression()
+	if err != nil { return nil, err }
+
+	err = this.ExpectValue(lexer.Ident, "in")
+	if err != nil { return nil, err }
+
+	for this.Is(lexer.Symbol) && this.ValueIs("|") {
+		cas, err := this.parseCase()
+		if err != nil { return nil, err }
+		match.Cases = append(match.Cases, cas)
+	}
+
+	return match, nil
+}
+
+func (this *treeParser) parseCase () (*entity.Case, error) {
+	err := this.ExpectValue(lexer.Symbol, "|")
+	if err != nil { return nil, err }
+	cas := &entity.Case {
+		Position: this.Pos(),
+	}
+
+	this.Next()
+	cas.Declaration, err = this.parseDeclaration()
+	if err != nil { return nil, err }
+	this.Next()
+	cas.Expression, err = this.parseExpression()
+	if err != nil { return nil, err }
+	
+	return cas, nil
+}
+
 func (this *treeParser) parseLoop () (*entity.Loop, error) {
 	err := this.ExpectValue(lexer.Ident, "loop")
 	if err != nil { return nil, err }