Add support for qualified COLUMNS matchers (test_table.COLUMNS)

- Detect qualified COLUMNS patterns when parsing dotted identifiers
- Parse test_table.COLUMNS(id) as QualifiedColumnsListMatcher
- Parse test_table.COLUMNS('pattern') as QualifiedColumnsRegexpMatcher
- Add parseQualifiedColumnsMatcher function to handle these cases

Author: claude

parser/expression.go

@@ -512,6 +512,11 @@ func (p *Parser) parseIdentifierOrFunction() ast.Expression {
 
 	// Check for function call after qualified name
 	if p.currentIs(token.LPAREN) {
+		// Special case: qualified COLUMNS matcher (e.g., test_table.COLUMNS(id))
+		if len(parts) >= 2 && strings.ToUpper(parts[len(parts)-1]) == "COLUMNS" {
+			qualifier := strings.Join(parts[:len(parts)-1], ".")
+			return p.parseQualifiedColumnsMatcher(qualifier, pos)
+		}
 		return p.parseFunctionCall(strings.Join(parts, "."), pos)
 	}
 
@@ -2191,6 +2196,58 @@ func (p *Parser) parseColumnsMatcher() ast.Expression {
 	return matcher
 }
 
+// parseQualifiedColumnsMatcher parses qualified COLUMNS matchers like test_table.COLUMNS(id)
+// The qualifier is passed in and we're already positioned at LPAREN
+func (p *Parser) parseQualifiedColumnsMatcher(qualifier string, pos token.Position) ast.Expression {
+	matcher := &ast.ColumnsMatcher{
+		Position:  pos,
+		Qualifier: qualifier,
+	}
+
+	p.nextToken() // skip LPAREN
+
+	// Parse the arguments - either a string pattern or a list of identifiers
+	if p.currentIs(token.STRING) {
+		// String pattern: COLUMNS('pattern')
+		matcher.Pattern = p.current.Value
+		p.nextToken()
+	} else {
+		// Column list: COLUMNS(col1, col2, ...)
+		for !p.currentIs(token.RPAREN) && !p.currentIs(token.EOF) {
+			col := p.parseExpression(LOWEST)
+			if col != nil {
+				matcher.Columns = append(matcher.Columns, col)
+			}
+			if p.currentIs(token.COMMA) {
+				p.nextToken()
+			} else {
+				break
+			}
+		}
+	}
+
+	p.expect(token.RPAREN)
+
+	// Handle EXCEPT
+	if p.currentIs(token.EXCEPT) {
+		p.nextToken()
+		if p.expect(token.LPAREN) {
+			for !p.currentIs(token.RPAREN) && !p.currentIs(token.EOF) {
+				if p.currentIs(token.IDENT) {
+					matcher.Except = append(matcher.Except, p.current.Value)
+					p.nextToken()
+				}
+				if p.currentIs(token.COMMA) {
+					p.nextToken()
+				}
+			}
+			p.expect(token.RPAREN)
+		}
+	}
+
+	return matcher
+}
+
 func (p *Parser) parseArrayConstructor() ast.Expression {
 	pos := p.current.Pos
 	p.nextToken() // skip ARRAY

parser/testdata/02339_analyzer_matcher_basic/metadata.json

@@ -2,18 +2,6 @@
   "explain_todo": {
     "stmt105": true,
     "stmt106": true,
-    "stmt30": true,
-    "stmt31": true,
-    "stmt33": true,
-    "stmt34": true,
-    "stmt36": true,
-    "stmt37": true,
-    "stmt48": true,
-    "stmt49": true,
-    "stmt51": true,
-    "stmt52": true,
-    "stmt54": true,
-    "stmt55": true,
     "stmt63": true,
     "stmt64": true,
     "stmt66": true,

parser/testdata/03101_analyzer_identifiers_4/metadata.json

@@ -1,7 +1,6 @@
 {
   "explain_todo": {
     "stmt14": true,
-    "stmt17": true,
     "stmt18": true,
     "stmt7": true,
     "stmt9": true

parser/testdata/03144_invalid_filter/metadata.json

@@ -1,6 +1,5 @@
 {
   "explain_todo": {
-    "stmt3": true,
-    "stmt4": true
+    "stmt3": true
   }
 }