parser: assignments and objects are actually items and the same

parser/ast.go

@@ -8,28 +8,48 @@ type Node interface {
 	Pos() scanner.Pos
 }
 
-func (Source) node() {}
-func (Ident) node()  {}
-
-func (AssignStatement) node() {}
-func (ObjectStatement) node() {}
-
-func (LiteralType) node() {}
+func (ObjectList) node()  {}
+func (ObjectItem) node()  {}
 func (ObjectType) node()  {}
+func (LiteralType) node() {}
 func (ListType) node()    {}
+func (Ident) node()       {}
 
-// Source represents a single HCL source file
-type Source struct {
-	nodes []Node
+// ObjectList represents a list of ObjectItems. An HCL file itself is an
+// ObjectList.
+type ObjectList struct {
+	items []*ObjectItem
 }
 
-func (s *Source) add(node Node) {
-	s.nodes = append(s.nodes, node)
+func (o *ObjectList) add(item *ObjectItem) {
+	o.items = append(o.items, item)
 }
 
-func (s *Source) Pos() scanner.Pos {
+func (o *ObjectList) Pos() scanner.Pos {
 	// always returns the uninitiliazed position
-	return s.nodes[0].Pos()
+	return o.items[0].Pos()
+}
+
+// ObjectItem represents a HCL Object Item. An item is represented with a key
+// (or keys). It can be an assignment or an object (both normal and nested)
+type ObjectItem struct {
+	// key is either an Identifier or a String. The slice is only one lenght
+	// long, however if it's a nested object it'll can be larger than one. In
+	// that case "assign" is invalid as there is no assignments for a nested
+	// object.
+	key []Ident
+
+	// assign contains the position of "=", if any
+	assign scanner.Pos
+
+	// val is the item itself. It can be an object,list, number, bool or a
+	// string. If key lenght is larger than one, val can be only of type
+	// Object.
+	val Node
+}
+
+func (o *ObjectItem) Pos() scanner.Pos {
+	return o.key[0].Pos()
 }
 
 // IdentStatement represents an identifier.
@@ -41,27 +61,6 @@ func (i *Ident) Pos() scanner.Pos {
 	return i.token.Pos
 }
 
-// AssignStatement represents an assignment
-type AssignStatement struct {
-	lhs    Node        // left hand side of the assignment
-	rhs    Node        // right hand side of the assignment
-	assign scanner.Pos // position of "="
-}
-
-func (a *AssignStatement) Pos() scanner.Pos {
-	return a.lhs.Pos()
-}
-
-// ObjectStatment represents an object statement
-type ObjectStatement struct {
-	Idents []Node // the idents in elements in lexical order
-	ObjectType
-}
-
-func (o *ObjectStatement) Pos() scanner.Pos {
-	return o.Idents[0].Pos()
-}
-
 // LiteralType represents a literal of basic type. Valid types are:
 // scanner.NUMBER, scanner.FLOAT, scanner.BOOL and scanner.STRING
 type LiteralType struct {

parser/parser.go

@@ -29,10 +29,10 @@ var errEofToken = errors.New("EOF token found")
 // Parse returns the fully parsed source and returns the abstract syntax tree.
 func (p *Parser) Parse() (Node, error) {
 	defer un(trace(p, "ParseSource"))
-	node := &Source{}
+	node := &ObjectList{}
 
 	for {
-		n, err := p.parseNode()
+		n, err := p.parseObjectItem()
 		if err == errEofToken {
 			break // we are finished
 		}
@@ -47,15 +47,15 @@ func (p *Parser) Parse() (Node, error) {
 	return node, nil
 }
 
-func (p *Parser) parseNode() (Node, error) {
-	defer un(trace(p, "ParseNode"))
+func (p *Parser) parseObjectItem() (*ObjectItem, error) {
+	defer un(trace(p, "ParseObjectItem"))
 
 	tok := p.scan()
 	fmt.Println(tok) // debug
 
 	switch tok.Type {
 	case scanner.ASSIGN:
-		return p.parseAssignment()
+		// return p.parseAssignment()
 	case scanner.LBRACK:
 		// return p.parseListType()
 	case scanner.LBRACE:
@@ -66,39 +66,9 @@ func (p *Parser) parseNode() (Node, error) {
 		return nil, errEofToken
 	}
 
-	if tok.Type.IsIdentifier() {
-		if p.prevTok.Type.IsIdentifier() {
-			return p.parseObjectStatement()
-		}
-
-		if tok.Type.IsLiteral() {
-			return p.parseLiteralType()
-		}
-		return p.parseIdent()
-	}
-
 	return nil, fmt.Errorf("not yet implemented: %s", tok.Type)
 }
 
-// parseAssignment parses an assignment and returns a AssignStatement AST
-func (p *Parser) parseAssignment() (*AssignStatement, error) {
-	defer un(trace(p, "ParseAssignment"))
-	a := &AssignStatement{
-		lhs: &Ident{
-			token: p.prevTok,
-		},
-		assign: p.tok.Pos,
-	}
-
-	n, err := p.parseNode()
-	if err != nil {
-		return nil, err
-	}
-
-	a.rhs = n
-	return a, nil
-}
-
 // parseIdent parses a generic identifier and returns a Ident AST
 func (p *Parser) parseIdent() (*Ident, error) {
 	defer un(trace(p, "ParseIdent"))
@@ -117,14 +87,6 @@ func (p *Parser) parseLiteralType() (*LiteralType, error) {
 	}, nil
 }
 
-// parseObjectStatement parses an object statement returns an ObjectStatement
-// AST. ObjectsStatements represents both normal and nested objects statement
-func (p *Parser) parseObjectStatement() (*ObjectStatement, error) {
-	defer un(trace(p, "ParseObjectStatement"))
-
-	return nil, errors.New("ObjectStatement is not implemented yet")
-}
-
 // parseObjectType parses an object type and returns a ObjectType AST
 func (p *Parser) parseObjectType() (*ObjectType, error) {
 	return nil, errors.New("ObjectType is not implemented yet")

parser/parser_test.go

@@ -1,6 +1,9 @@
 package parser
 
-import "testing"
+import (
+	"fmt"
+	"testing"
+)
 
 func TestAssignStatement(t *testing.T) {
 	src := `ami = "${var.foo}"`
@@ -14,4 +17,13 @@ func TestAssignStatement(t *testing.T) {
 	if n.Pos().Line != 1 {
 		t.Errorf("AssignStatement position is wrong\n\twant: '%d'\n\tgot : '%d'", 1, n.Pos().Line)
 	}
+
+	n1, ok := n.(*ObjectList)
+	if !ok {
+		t.Fatal("First Node should be of type Source")
+	}
+
+	for _, ns := range n1.nodes {
+		fmt.Printf("ns = %+v\n", ns)
+	}
 }