add :=

Author: StpMax

mindsdb_sql_parser/lexer.py

@@ -72,7 +72,7 @@ class MindsDBLexer(Lexer):
 
         # Operators
         PLUS, MINUS, MATCH, NOT_MATCH, DIVIDE, MODULO,
-        RIGHT_SHIFT, LEFT_SHIFT, EQUALS, NEQUALS, GREATER, GEQ, LESS, LEQ,
+        ASSIGN_COLON, RIGHT_SHIFT, LEFT_SHIFT, EQUALS, NEQUALS, GREATER, GEQ, LESS, LEQ,
         AND, OR, NOT, IS, IS_NOT, TYPECAST,
         IN, NOT_IN, LIKE, NOT_LIKE, CONCAT, BETWEEN, WINDOW, OVER, PARTITION_BY,
         VECT_L2, VECT_L1, VECT_INNER, VECT_COS, VECT_HAMM, VECT_JACC,
@@ -296,6 +296,7 @@ class MindsDBLexer(Lexer):
     NOT_MATCH = r'!~'
     DIVIDE = r'/'
     MODULO = r'%'
+    ASSIGN_COLON = r':='
     RIGHT_SHIFT = r'>>'
     LEFT_SHIFT = r'<<'
     EQUALS = r'='

mindsdb_sql_parser/parser.py

@@ -46,8 +46,8 @@ class MindsDBParser(Parser):
         ('left', OR),
         ('left', AND),
         ('right', UNOT),
-        ('left', EQUALS, NEQUALS),
-        ('nonassoc', LESS, LEQ, GREATER, GEQ, IN, NOT_IN, BETWEEN, IS, IS_NOT, NOT_LIKE, LIKE),
+        ('left', EQUALS, NEQUALS, ASSIGN_COLON),
+        ('nonassoc', LESS, LEQ, GREATER, GEQ, IN, NOT_IN, BETWEEN, IS, IS_NOT, NOT_LIKE, LIKE, RIGHT_SHIFT, LEFT_SHIFT),
         ('left', JSON_GET),
         ('left', PLUS, MINUS),
         ('left', STAR, DIVIDE, TYPECAST, MODULO),
@@ -1631,6 +1631,7 @@ def star(self, p):
        'expr STAR expr',
        'expr DIVIDE expr',
        'expr MODULO expr',
+       'expr ASSIGN_COLON expr',
        'expr EQUALS expr',
        'expr NEQUALS expr',
        'expr RIGHT_SHIFT expr',
@@ -1659,6 +1660,10 @@ def star(self, p):
        'expr NOT_IN expr',
        'expr IN expr',)
     def expr(self, p):
+        if p[1] == ':=':
+            # allow 'assign' only for variables
+            if not isinstance(p[0], Variable):
+                raise ParsingException("Assignment `:=` allowed only to variables (@var := ...)")
         if hasattr(p, 'LAST'):
             arg1 = Last()
         else: