implement HeredocExpr

Author: itchyny

ast/node.go

@@ -517,7 +517,7 @@ type Ident struct {
 func (i *Ident) Pos() Pos { return i.NamePos }
 
 // LambdaExpr node represents lambda.
-// vimlparsr: LAMBDA .rlist .left
+// vimlparser: LAMBDA .rlist .left
 // { Params -> Expr }
 type LambdaExpr struct {
 	Lcurlybrace Pos      // position of "{"
@@ -528,14 +528,25 @@ type LambdaExpr struct {
 func (i *LambdaExpr) Pos() Pos { return i.Lcurlybrace }
 
 // ParenExpr node represents a parenthesized expression.
-// vimlparsr: PARENEXPR .value
+// vimlparser: PARENEXPR .value
 type ParenExpr struct {
 	Lparen Pos  // position of "("
 	X      Expr // parenthesized expression
 }
 
 func (i *ParenExpr) Pos() Pos { return i.Lparen }
 
+// HeredocExpr node represents a heredoc expression.
+// vimlparser: HEREDOC .rlist .op .body
+type HeredocExpr struct {
+	OpPos     Pos    // position of "=<<"
+	Flags     []Expr // modifiers [trim]; or nil
+	EndMarker string // {endmarker}
+	Body      []Expr // body
+}
+
+func (i *HeredocExpr) Pos() Pos { return i.OpPos }
+
 // stmtNode() ensures that only ExComamnd and Comment nodes can be assigned to
 // an Statement.
 //
@@ -588,3 +599,4 @@ func (*CurlyNameExpr) exprNode() {}
 func (*Ident) exprNode()         {}
 func (*LambdaExpr) exprNode()    {}
 func (*ParenExpr) exprNode()     {}
+func (*HeredocExpr) exprNode()   {}

ast/walk.go

@@ -201,6 +201,10 @@ func Walk(v Visitor, node Node) {
 	case *ParenExpr:
 		Walk(v, n.X)
 
+	case *HeredocExpr:
+		walkExprList(v, n.Flags)
+		walkExprList(v, n.Body)
+
 	default:
 		panic(fmt.Sprintf("ast.Walk: unexpected node type %T", n))
 	}

compiler/compiler.go

@@ -440,6 +440,28 @@ func (c *Compiler) compileExpr(node ast.Expr) string {
 			params = append(params, p.Name)
 		}
 		return fmt.Sprintf("(lambda (%s) %s)", strings.Join(params, " "), c.compileExpr(n.Expr))
+	case *ast.HeredocExpr:
+		var flags string
+		if len(n.Flags) == 0 {
+			flags = "(list)"
+		} else {
+			xs := make([]string, len(n.Flags))
+			for i, f := range n.Flags {
+				xs[i] = `"` + c.compileExpr(f) + `"`
+			}
+			flags = fmt.Sprintf("(list %s)", strings.Join(xs, " "))
+		}
+		var body string
+		if len(n.Body) == 0 {
+			body = "(list)"
+		} else {
+			xs := make([]string, len(n.Body))
+			for i, p := range n.Body {
+				xs[i] = `"` + escape(c.compileExpr(p), "\n\t\r") + `"`
+			}
+			body = fmt.Sprintf("(list %s)", strings.Join(xs, " "))
+		}
+		return fmt.Sprintf(`(heredoc %s "%s" %s)`, flags, n.EndMarker, body)
 	case *ast.ParenExpr:
 		return c.compileExpr(n.X)
 	}
@@ -450,7 +472,16 @@ func escape(s string, chars string) string {
 	r := ""
 	for _, c := range s {
 		if strings.IndexRune(chars, c) != -1 {
-			r += `\` + string(c)
+			switch c {
+			case '\n':
+				r += `\n`
+			case '\t':
+				r += `\t`
+			case '\r':
+				r += `\r`
+			default:
+				r += `\` + string(c)
+			}
 		} else {
 			r += string(c)
 		}

go/export.go

@@ -453,6 +453,14 @@ func newAstNode(n *VimNode, filename string) ast.Node {
 			Value:    n.value.(string),
 		}
 
+	case NODE_HEREDOC:
+		return &ast.HeredocExpr{
+			OpPos:     pos,
+			Flags:     newRlist(*n, filename),
+			EndMarker: n.op,
+			Body:      newBodyExprs(*n, filename),
+		}
+
 	case NODE_PARENEXPR:
 		n := n.value.(*VimNode)
 		return &ast.ParenExpr{
@@ -535,6 +543,14 @@ func newBody(n VimNode, filename string) []ast.Statement {
 	return body
 }
 
+func newBodyExprs(n VimNode, filename string) []ast.Expr {
+	body := make([]ast.Expr, len(n.body))
+	for i, node := range n.body {
+		body[i] = newExprNode(node, filename)
+	}
+	return body
+}
+
 func newIdents(n VimNode, filename string) []*ast.Ident {
 	var idents []*ast.Ident
 	if n.rlist != nil {