From 246b68b0c277d627f4c210ebc10859c2d3503055 Mon Sep 17 00:00:00 2001
From: Arpad Ryszka <arpad.ryszka@gmail.com>
Date: Sun, 6 Aug 2017 20:43:52 +0200
Subject: [PATCH] validation

---
 char.go     |  1 +
 choice.go   | 10 ++++++++++
 parse.go    |  1 +
 sequence.go | 14 ++++++++++++--
 syntax.go   |  4 ++++
 5 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/char.go b/char.go
index 2f2728a..ff2c184 100644
--- a/char.go
+++ b/char.go
@@ -27,6 +27,7 @@ func (p *charParser) nodeName() string                  { return p.name }
 func (p *charParser) nodeID() int                       { return p.id }
 func (p *charParser) setID(id int)                      { p.id = id }
 func (p *charParser) commitType() CommitType            { return Alias }
+func (p *charParser) validate(*registry, *idSet) error  { return nil }
 func (p *charParser) normalize(*registry, *idSet) error { return nil }
 
 func (p *charParser) init(r *registry) error { return nil }
diff --git a/choice.go b/choice.go
index 57a41f1..ed1e98a 100644
--- a/choice.go
+++ b/choice.go
@@ -38,6 +38,16 @@ func (d *choiceDefinition) nodeID() int            { return d.id }
 func (d *choiceDefinition) setID(id int)           { d.id = id }
 func (d *choiceDefinition) commitType() CommitType { return d.commit }
 
+func (d *choiceDefinition) validate(r *registry, path *idSet) error {
+	for i := range d.elements {
+		if _, ok := r.definition(d.elements[i]); !ok {
+			return parserNotFound(d.elements[i])
+		}
+	}
+
+	return nil
+}
+
 func (d *choiceDefinition) normalize(r *registry, path *idSet) error {
 	if path.has(d.id) {
 		return nil
diff --git a/parse.go b/parse.go
index cec0809..b2f9509 100644
--- a/parse.go
+++ b/parse.go
@@ -7,6 +7,7 @@ type definition interface {
 	nodeID() int
 	commitType() CommitType
 	setID(int)
+	validate(*registry, *idSet) error
 	normalize(*registry, *idSet) error
 	init(*registry) error
 	setIncludedBy(*registry, int, *idSet) error
diff --git a/sequence.go b/sequence.go
index d133ca0..b8953a1 100644
--- a/sequence.go
+++ b/sequence.go
@@ -44,6 +44,16 @@ func (d *sequenceDefinition) nodeID() int            { return d.id }
 func (d *sequenceDefinition) setID(id int)           { d.id = id }
 func (d *sequenceDefinition) commitType() CommitType { return d.commit }
 
+func (d *sequenceDefinition) validate(r *registry, path *idSet) error {
+	for i := range d.items {
+		if _, ok := r.definition(d.items[i].Name); !ok {
+			return parserNotFound(d.items[i].Name)
+		}
+	}
+
+	return nil
+}
+
 func (d *sequenceDefinition) normalize(r *registry, path *idSet) error {
 	if path.has(d.id) {
 		return nil
@@ -51,12 +61,12 @@ func (d *sequenceDefinition) normalize(r *registry, path *idSet) error {
 
 	path.set(d.id)
 	for i := range d.items {
-		element, ok := r.definition(d.items[i].Name)
+		item, ok := r.definition(d.items[i].Name)
 		if !ok {
 			return parserNotFound(d.items[i].Name)
 		}
 
-		element.normalize(r, path)
+		item.normalize(r, path)
 	}
 
 	return nil
diff --git a/syntax.go b/syntax.go
index d81deac..a9637e6 100644
--- a/syntax.go
+++ b/syntax.go
@@ -144,6 +144,10 @@ func (s *Syntax) Init() error {
 		return ErrRootAlias
 	}
 
+	if err := s.root.validate(s.registry, &idSet{}); err != nil {
+		return err
+	}
+
 	if err := s.root.normalize(s.registry, &idSet{}); err != nil {
 		return err
 	}