From ae59ad57f45cadcd2a568fb96ff0db6b3e821960 Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Fri, 18 Sep 2020 17:08:33 +1000
Subject: [PATCH] tree wip

---
 pkg/yqlib/path_tokeniser.go |  7 +++--
 pkg/yqlib/path_tree.go      | 51 +++++++++++++++++++++++++++++++++++++
 pkg/yqlib/path_tree_test.go |  1 +
 3 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 pkg/yqlib/path_tree.go
 create mode 100644 pkg/yqlib/path_tree_test.go

diff --git a/pkg/yqlib/path_tokeniser.go b/pkg/yqlib/path_tokeniser.go
index a76cf75e..848ee149 100644
--- a/pkg/yqlib/path_tokeniser.go
+++ b/pkg/yqlib/path_tokeniser.go
@@ -23,9 +23,8 @@ func initTokens() {
 	}
 	Tokens = []string{
 		"OPERATION",   // ==, OR, AND
-		"PATH",        // a.b.c
+		"PATH_KEY",    // apples
 		"ARRAY_INDEX", // 1234
-		"PATH_JOIN",   // "."
 	}
 	Tokens = append(Tokens, Literals...)
 	TokenIds = make(map[string]int)
@@ -79,8 +78,8 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`\[-?[0-9]+\]`), numberToken("ARRAY_INDEX", true))
 	lexer.Add([]byte(`-?[0-9]+`), numberToken("ARRAY_INDEX", false))
 	lexer.Add([]byte("( |\t|\n|\r)+"), skip)
-	lexer.Add([]byte(`"[^ "]+"`), wrappedToken("PATH"))
-	lexer.Add([]byte(`[^ \.\[\(\)=]+`), token("PATH"))
+	lexer.Add([]byte(`"[^ "]+"`), wrappedToken("PATH_KEY"))
+	lexer.Add([]byte(`[^ \.\[\(\)=]+`), token("PATH_KEY"))
 	lexer.Add([]byte(`\.`), skip)
 	err := lexer.Compile()
 	if err != nil {
diff --git a/pkg/yqlib/path_tree.go b/pkg/yqlib/path_tree.go
new file mode 100644
index 00000000..038d4015
--- /dev/null
+++ b/pkg/yqlib/path_tree.go
@@ -0,0 +1,51 @@
+package yqlib
+
+import lex "github.com/timtadh/lexmachine"
+
+type PathElementType uint32
+
+const (
+	PathKey PathElementType = 1 << iota
+	ArrayIndex
+	Operation
+)
+
+type OperationType uint32
+
+const (
+	None OperationType = 1 << iota
+	Or
+	And
+	ChildEquals
+)
+
+type PathElement struct {
+	PathElementType PathElementType
+	OperationType   OperationType
+	Value           interface{}
+	ChildElements   [][]*PathElement
+}
+
+func parseTree(tokens []*lex.Token, currentElement *PathElement, allElements []*PathElement) []*PathElement {
+	currentToken, remainingTokens := tokens[0], tokens[1:]
+
+	switch currentToken.Type {
+	case TokenIds["PATH_KEY"]:
+		currentElement.PathElementType = PathKey
+		currentElement.OperationType = None
+		currentElement.Value = currentToken.Value
+	}
+
+	if len(remainingTokens) == 0 {
+		return append(allElements, currentElement)
+	}
+	return parseTree(remainingTokens, &PathElement{}, append(allElements, currentElement))
+
+}
+
+func ParseTree(tokens []*lex.Token) []*PathElement {
+	if len(tokens) == 0 {
+		return make([]*PathElement, 0)
+	}
+	return parseTree(tokens, &PathElement{}, make([]*PathElement, 0))
+}
diff --git a/pkg/yqlib/path_tree_test.go b/pkg/yqlib/path_tree_test.go
new file mode 100644
index 00000000..88c44e97
--- /dev/null
+++ b/pkg/yqlib/path_tree_test.go
@@ -0,0 +1 @@
+package yqlib