Fix adql translator for nested log functions

Author: kimakan

src/queryparser/adql/adqltranslator.py

@@ -4,6 +4,7 @@
 
 import antlr4
 from antlr4.error.ErrorListener import ErrorListener
+import re
 
 from .ADQLLexer import ADQLLexer
 from .ADQLParser import ADQLParser
@@ -470,15 +471,6 @@ def visitIntersects(self, ctx):
         _remove_children(ctx)
         self.contexts[ctx] = ctx_text
 
-    def visitMath_function(self, ctx):
-        ctx_text = ctx.getText()
-        if self.output_sql == 'postgresql' and ctx_text[:5].lower() == 'log10':
-            _remove_children(ctx)
-            self.contexts[ctx] = 'LOG' + ctx_text[5:]
-        elif self.output_sql == 'postgresql' and ctx_text[:3].lower() == 'log':
-            _remove_children(ctx)
-            self.contexts[ctx] = 'LN' + ctx_text[3:]
-
 
 class SelectQueryListener(ADQLParserListener):
     def __init__(self):
@@ -691,4 +683,9 @@ def to_postgresql(self):
         translator_visitor.visit(self.tree)
 
         translated_query = self.translate(translator_visitor)
+
+        # Translate LOG10 to LOG and LOG to LN. It's not the most elegant solution but it works.
+        translated_query = re.sub(r'(?<=[\+\-\*/\(\s,])log\(', 'LN(', translated_query, flags=re.IGNORECASE)
+        translated_query = re.sub(r'(?<=[\+\-\*/\(\s,])log10\(', 'LOG(', translated_query, flags=re.IGNORECASE)
+
         return translated_query

src/queryparser/testing/tests.yaml

@@ -889,6 +889,14 @@ adql_mysql_tests:
 # coordsys will ensure the backward compatibility for adql2.0 but can be removed
 # later.
 adql_postgresql_tests:
+    -
+        - SELECT TOP 10 LOG(a) as a FROM db.tab
+        - SELECT LN(a) AS a FROM db.tab LIMIT 10;
+
+    -
+        - SELECT TOP 10 LOG10(a) as a FROM db.tab
+        - SELECT LOG(a) AS a FROM db.tab LIMIT 10;
+
     -
         - SELECT TOP 10 AREA(CIRCLE('ICRS', "tab".RA, -2.23, 176.98)) FROM db.tab
         - SELECT square_degrees(area(scircle(spoint(RADIANS("tab".RA), RADIANS(-2.23)), RADIANS(176.98)))) AS adql_area FROM db.tab LIMIT 10;