reconstruct

engine/ast.py

@@ -160,12 +160,14 @@ class TableInfo:
         return self.get_col(col_name).cname
 
     def add_alias(self, alias):
-        # TODO: Exception when alias already defined.
         # TODO: Scoping of alias should be constrainted in the query.
+        if alias in self.cxt.tables_byname.keys():
+            print("Error: table alias already exists")
+            return
         self.cxt.tables_byname[alias] = self
         self.alias.add(alias)
         
-    def parse_tablenames(self, colExpr, materialize = True, raw = False):
+    def parse_col_names(self, colExpr, materialize = True, raw = False):
         # get_col = self.get_col if materialize else self.get_col_d
 
         parsedColExpr = colExpr.split('.')
@@ -177,7 +179,7 @@ class TableInfo:
             if datasource is None:
                 raise ValueError(f'Table name/alias not defined{parsedColExpr[0]}')
             else:
-                ret = datasource.parse_tablenames(parsedColExpr[1], raw)
+                ret = datasource.parse_col_names(parsedColExpr[1], raw)
         from engine.expr import index_expr
         string = ret.reference() + index_expr
         if self.groupinfo is not None and ret and ret in self.groupinfo.raw_groups:
@@ -205,6 +207,23 @@ class Context:
     LOG_INFO = 'INFO'
     LOG_ERROR = 'ERROR'
     LOG_SILENT = 'SILENT'
+    def new(self):
+        self.tmp_names = set()
+        self.udf_map = dict()
+        self.headers = set(['\"./server/libaquery.h\"'])
+        self.finalized = False
+        # read header
+        self.ccode = ''
+        self.ccodelet = ''
+        with open('header.cxx', 'r') as outfile:
+            self.ccode = outfile.read()         
+        # datasource will be availible after `from' clause is parsed
+        # and will be deactivated when the `from' is out of scope
+        self.datasource = None
+        self.ds_stack = []
+        self.scans = []
+        self.removing_scan = False
+
     def __init__(self): 
         self.tables:list[TableInfo] = []
         self.tables_byname = dict()

engine/expr.py

@@ -115,7 +115,7 @@ class expr(ast_node):
                 p.isvector = True
                 p = p.parent
                 
-            self._expr, self.raw_col = self.datasource.parse_tablenames(node, self.materialize_cols, True)
+            self._expr, self.raw_col = self.datasource.parse_col_names(node, self.materialize_cols, True)
             self.raw_col = self.raw_col if type(self.raw_col) is ColRef else None
             if self.__abs and self.raw_col:
                 self._expr = self.raw_col.reference() + ("" if self.inside_agg else index_expr)

engine/projection.py

@@ -45,12 +45,14 @@ class projection(ast_node):
                             print(f'from func over table{node}')
                     elif type(value) is str:
                         self.datasource = self.context.tables_byname[value]
+                    if 'name' in value:
+                        self.datasource.add_alias(value['name'])
                 if 'assumptions' in from_clause:
                     self.assumptions = enlist(from_clause['assumptions'])
                     
             elif type(from_clause) is str:
                 self.datasource = self.context.tables_byname[from_clause]
-            
+                
             if self.datasource is None:
                 raise ValueError('spawn error: from clause')
            

engine/types.py

@@ -26,6 +26,7 @@ class Int(Types):
     name = "Int"
     cname = "int"
     ctype_name = "types::AINT"
+    
 class Float(Types):
     name = "Float"
     cname = "float"