parser: more improvements around ATS

parser/ast.go

@@ -2,18 +2,6 @@ package parser
 
 import "github.com/fatih/hcl/scanner"
 
-type NodeType int
-
-const (
-	Unknown NodeType = 0
-	Number
-	Float
-	Bool
-	String
-	List
-	Object
-)
-
 // Node is an element in the abstract syntax tree.
 type Node interface {
 	node()
@@ -109,15 +97,18 @@ func (o *ObjectStatement) Pos() scanner.Pos {
 // LiteralType represents a literal of basic type. Valid types are:
 // scanner.NUMBER, scanner.FLOAT, scanner.BOOL and scanner.STRING
 type LiteralType struct {
-	token scanner.Token
+	*Ident
 }
 
-func (l *LiteralType) String() string {
-	return l.token.Text
-}
-
-func (l *LiteralType) Pos() scanner.Pos {
-	return l.token.Pos
+// isValid() returns true if the underlying identifier satisfies one of the
+// valid types.
+func (l *LiteralType) isValid() bool {
+	switch l.token.Type {
+	case scanner.NUMBER, scanner.FLOAT, scanner.BOOL, scanner.STRING:
+		return true
+	default:
+		return false
+	}
 }
 
 // ListStatement represents a HCL List type

parser/parser.go

@@ -55,7 +55,7 @@ func (p *Parser) parseNode() (Node, error) {
 
 	if tok.Type.IsLiteral() {
 		if p.prevTok.Type.IsLiteral() {
-			return p.parseObjectType()
+			return p.parseObjectStatement()
 		}
 
 		tok := p.scan()
@@ -70,6 +70,7 @@ func (p *Parser) parseNode() (Node, error) {
 	return nil, errors.New("not yet implemented")
 }
 
+// parseAssignment parses an assignment and returns a AssignStatement AST
 func (p *Parser) parseAssignment() (*AssignStatement, error) {
 	defer un(trace(p, "ParseAssignment"))
 	a := &AssignStatement{
@@ -88,6 +89,7 @@ func (p *Parser) parseAssignment() (*AssignStatement, error) {
 	return a, nil
 }
 
+// parseIdent parses a generic identifier and returns a Ident AST
 func (p *Parser) parseIdent() (*Ident, error) {
 	defer un(trace(p, "ParseIdent"))
 
@@ -100,12 +102,37 @@ func (p *Parser) parseIdent() (*Ident, error) {
 	}, nil
 }
 
-func (p *Parser) parseObjectType() (*ObjectStatement, error) {
+// parseLiteralType parses a literal type and returns a LiteralType AST
+func (p *Parser) parseLiteralType() (*LiteralType, error) {
+	i, err := p.parseIdent()
+	if err != nil {
+		return nil, err
+	}
+
+	l := &LiteralType{}
+	l.Ident = i
+
+	if !l.isValid() {
+		return nil, fmt.Errorf("Identifier is not a LiteralType: %s", l.token)
+	}
+
+	return l, nil
+}
+
+// parseObjectStatement parses an object statement returns an ObjectStatement
+// AST. ObjectsStatements represents both normal and nested objects statement
+func (p *Parser) parseObjectStatement() (*ObjectStatement, error) {
 	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")
+}
+
+// parseListType parses a list type and returns a ListType AST
 func (p *Parser) parseListType() (*ListType, error) {
-	return nil, errors.New("ListStatement is not implemented yet")
+	return nil, errors.New("ListType is not implemented yet")
 }
 
 // scan returns the next token from the underlying scanner.