Add JSON array path notation support for empty brackets [] (#100)

Author: kyleconroy

parser/expression.go

@@ -1489,12 +1489,59 @@ func (p *Parser) parseIsExpression(left ast.Expression) ast.Expression {
 }
 
 func (p *Parser) parseArrayAccess(left ast.Expression) ast.Expression {
+	pos := p.current.Pos
+	p.nextToken() // skip [
+
+	// Check for empty brackets [] - this is JSON array path notation
+	// json.arr[].field becomes Identifier json.arr.:`Array(JSON)`.field
+	if p.currentIs(token.RBRACKET) {
+		p.nextToken() // skip ]
+
+		if ident, ok := left.(*ast.Identifier); ok {
+			// Append the JSON array type notation to the identifier
+			ident.Parts = append(ident.Parts, ":`Array(JSON)`")
+
+			// Continue parsing any dot accesses that follow
+			for p.currentIs(token.DOT) {
+				p.nextToken() // skip .
+
+				if p.currentIs(token.CARET) {
+					// Handle JSON path parent access: x.^c0
+					p.nextToken() // skip ^
+					if p.currentIs(token.IDENT) || p.current.Token.IsKeyword() {
+						ident.Parts = append(ident.Parts, "^"+p.current.Value)
+						p.nextToken()
+					} else {
+						break
+					}
+				} else if p.currentIs(token.IDENT) || p.current.Token.IsKeyword() {
+					ident.Parts = append(ident.Parts, p.current.Value)
+					p.nextToken()
+
+					// Check for nested empty array access (e.g., arr[].nested[].field)
+					if p.currentIs(token.LBRACKET) {
+						return p.parseArrayAccess(ident)
+					}
+				} else {
+					break
+				}
+			}
+			return ident
+		}
+
+		// Not an identifier, fall through to create ArrayAccess with nil index
+		return &ast.ArrayAccess{
+			Position: pos,
+			Array:    left,
+			Index:    nil,
+		}
+	}
+
+	// Regular array access with index expression
 	expr := &ast.ArrayAccess{
-		Position: p.current.Pos,
+		Position: pos,
 		Array:    left,
 	}
-
-	p.nextToken() // skip [
 	expr.Index = p.parseExpression(LOWEST)
 	p.expect(token.RBRACKET)
 

parser/testdata/03553_json_shared_data_advanced_serialization/metadata.json

@@ -1,104 +1 @@
-{
-  "explain_todo": {
-    "stmt117": true,
-    "stmt119": true,
-    "stmt121": true,
-    "stmt123": true,
-    "stmt125": true,
-    "stmt127": true,
-    "stmt129": true,
-    "stmt131": true,
-    "stmt133": true,
-    "stmt139": true,
-    "stmt141": true,
-    "stmt143": true,
-    "stmt145": true,
-    "stmt155": true,
-    "stmt157": true,
-    "stmt159": true,
-    "stmt161": true,
-    "stmt163": true,
-    "stmt165": true,
-    "stmt167": true,
-    "stmt169": true,
-    "stmt171": true,
-    "stmt173": true,
-    "stmt175": true,
-    "stmt177": true,
-    "stmt185": true,
-    "stmt187": true,
-    "stmt189": true,
-    "stmt191": true,
-    "stmt193": true,
-    "stmt195": true,
-    "stmt197": true,
-    "stmt199": true,
-    "stmt201": true,
-    "stmt207": true,
-    "stmt209": true,
-    "stmt21": true,
-    "stmt211": true,
-    "stmt213": true,
-    "stmt223": true,
-    "stmt225": true,
-    "stmt227": true,
-    "stmt229": true,
-    "stmt23": true,
-    "stmt231": true,
-    "stmt233": true,
-    "stmt235": true,
-    "stmt237": true,
-    "stmt239": true,
-    "stmt241": true,
-    "stmt243": true,
-    "stmt245": true,
-    "stmt25": true,
-    "stmt253": true,
-    "stmt255": true,
-    "stmt257": true,
-    "stmt259": true,
-    "stmt261": true,
-    "stmt263": true,
-    "stmt265": true,
-    "stmt267": true,
-    "stmt269": true,
-    "stmt27": true,
-    "stmt275": true,
-    "stmt277": true,
-    "stmt279": true,
-    "stmt281": true,
-    "stmt29": true,
-    "stmt291": true,
-    "stmt293": true,
-    "stmt295": true,
-    "stmt297": true,
-    "stmt299": true,
-    "stmt301": true,
-    "stmt303": true,
-    "stmt305": true,
-    "stmt307": true,
-    "stmt309": true,
-    "stmt31": true,
-    "stmt311": true,
-    "stmt313": true,
-    "stmt33": true,
-    "stmt35": true,
-    "stmt37": true,
-    "stmt43": true,
-    "stmt45": true,
-    "stmt47": true,
-    "stmt49": true,
-    "stmt59": true,
-    "stmt61": true,
-    "stmt63": true,
-    "stmt65": true,
-    "stmt67": true,
-    "stmt69": true,
-    "stmt71": true,
-    "stmt73": true,
-    "stmt75": true,
-    "stmt77": true,
-    "stmt79": true,
-    "stmt81": true
-  }
-}
+{}