fix bad expr issue

Author: joenorton

demo/basic_demo/hello.sans

@@ -7,9 +7,9 @@ datasource in = inline_csv do
 end
 
 table t = from(in) do
-  derive(base2 = a * 2)
-  filter(base2 > 10)
-  select a, base2
+	derive(base2 = a * 2)
+	filter(base2 > 10)
+	select a, base2
 end
 
 t select a, base2

demo/hello.sans

@@ -7,9 +7,9 @@ datasource in = inline_csv do
 end
 
 table t = from(in) do
-  derive(base2 = a * 2)
-  filter(base2 > 10)
-  select a, base2
+	derive(base2 = a * 2)
+	filter(base2 > 10)
+	select a, base2
 end
 
 t select a, base2

demo/run_diff_clin_demo/dh_out/inputs/source/expanded.sans

@@ -1,7 +1,7 @@
 # sans 0.1
 datasource lb = csv("lb.csv", columns(USUBJID, VISITNUM, LBDTC, LBTESTCD, LBORRES, LBSTRESN, LBSTRESU))
 table __t2__ = from(lb)
-table __t3__ = __t2__ filter((LBTESTCD = "HBA1C"))
+table __t3__ = __t2__ filter((LBTESTCD == "HBA1C"))
 table __t4__ = __t3__ rename(LBSTRESN -> A1C)
 table __t5__ = __t4__ select USUBJID, VISITNUM, LBDTC, A1C
 table __t6__ = __t5__ derive(label = "HIGH")

demo/run_diff_clin_demo/dh_out/report.json

@@ -15,7 +15,7 @@
       "role": "expanded",
       "name": "expanded.sans",
       "path": "inputs/source/expanded.sans",
-      "sha256": "8ee2b5955a150e469790513f3315b46e55fee92b9735ee206a2e2cdf460d77b7"
+      "sha256": "b82be58593d60a1fbd0194e6c95d21ffc89cbc74e24c609c9148d22380136916"
     }
   ],
   "artifacts": [
@@ -93,13 +93,13 @@
   "timing": {
     "compile_ms": 3,
     "validate_ms": 0,
-    "execute_ms": 4
+    "execute_ms": 5
   },
-  "report_sha256": "036ebc06865a15c377b9b1a19a479dfa6aead367e24b17c435e92e945807afb6",
+  "report_sha256": "dee62c0f9d6dd407b3cbe6d4eab42d9bc7c94e6912486347b7e46650711b3247",
   "runtime": {
     "status": "ok",
     "timing": {
-      "execute_ms": 4
+      "execute_ms": 5
     }
   }
 }

demo/run_diff_clin_demo/dl_out/inputs/source/expanded.sans

@@ -1,7 +1,7 @@
 # sans 0.1
 datasource lb = csv("lb.csv", columns(USUBJID, VISITNUM, LBDTC, LBTESTCD, LBORRES, LBSTRESN, LBSTRESU))
 table __t2__ = from(lb)
-table __t3__ = __t2__ filter((LBTESTCD = "HBA1C"))
+table __t3__ = __t2__ filter((LBTESTCD == "HBA1C"))
 table __t4__ = __t3__ rename(LBSTRESN -> A1C)
 table __t5__ = __t4__ select USUBJID, VISITNUM, LBDTC, A1C
 table __t6__ = __t5__ derive(label = "LOW")

demo/run_diff_clin_demo/dl_out/report.json

@@ -15,7 +15,7 @@
       "role": "expanded",
       "name": "expanded.sans",
       "path": "inputs/source/expanded.sans",
-      "sha256": "0b1a75b07b02de945c8dded35d510880b19188b87eae828e338653de7d3bbd64"
+      "sha256": "3f89722b1e1297609b0a08f59b5759b8413505becd9178e882be1ee75feabd53"
     }
   ],
   "artifacts": [
@@ -95,7 +95,7 @@
     "validate_ms": 0,
     "execute_ms": 4
   },
-  "report_sha256": "b46f430e9534fabebfd545e5db3f39d5f2dfadcece58c16e57fdfddd96fc230f",
+  "report_sha256": "8d9b8ffcff2373c20407d041a80a53cf457edcbc3acbc9fbef412f21ceec1a78",
   "runtime": {
     "status": "ok",
     "timing": {

sans/sans/parser_expr.py

@@ -196,8 +196,8 @@ def parse_expression(self, min_precedence: int = 0) -> ExprNode:
                     "^=": "!=",
                     "~=": "!=",
                     "ne": "!=",
-                    "eq": "=",
-                    "==": "=",
+                    "eq": "==",
+                    "==": "==",
                     "lt": "<",
                     "le": "<=",
                     "gt": ">",

sans/sans/runtime.py

@@ -80,7 +80,7 @@ def _parse_value(raw: str) -> Any:
 
 def _compare_sas(left: Any, right: Any, op: str) -> bool:
     """Implements SAS-style comparison where None (missing) is smallest."""
-    if op == "=": return left == right
+    if op in {"=", "=="}: return left == right
     if op == "!=": return left != right
 
     # Missing value logic for <, <=, >, >=
@@ -425,7 +425,7 @@ def _eval_expr(node: Dict[str, Any], row: Dict[str, Any], formats: Optional[Dict
                 return left * right
             if op == "/":
                 return left / right
-        if op in {"=", "!=", "<", "<=", ">", ">="}:
+        if op in {"=", "==", "!=", "<", "<=", ">", ">="}:
             return _compare_sas(left, right, op)
         raise RuntimeFailure(
             "SANS_RUNTIME_UNSUPPORTED_EXPR_NODE",
@@ -494,7 +494,7 @@ def _eval_expr_assert(
         op = node.get("op")
         left = _eval_expr_assert(node.get("left"), tables, formats)
         right = _eval_expr_assert(node.get("right"), tables, formats)
-        if op in {"=", "!=", "<", "<=", ">", ">="}:
+        if op in {"=", "==", "!=", "<", "<=", ">", ">="}:
             return _compare_sas(left, right, op)
         if op in {"+", "-", "*", "/"}:
             if left is None or right is None:
@@ -568,7 +568,7 @@ def _eval_expr_sql(node: Dict[str, Any], row: Dict[str, Any], col_map: Dict[str,
                 return left * right
             if op == "/":
                 return left / right
-        if op in {"=", "!=", "<", "<=", ">", ">="}:
+        if op in {"=", "==", "!=", "<", "<=", ">", ">="}:
             return _compare_sas(left, right, op)
         raise RuntimeFailure(
             "SANS_RUNTIME_UNSUPPORTED_EXPR_NODE",

sans/sans/sans_script/parser.py

@@ -1200,16 +1200,16 @@ def _collect_block_by_parens(self, header: _Line, start_word: str) -> tuple[List
     def _ensure_sans_expr_rules(self, text: str, line_no: int) -> None:
         if not self._file_name:
             return
-        # Basic check for == and !=
+        # Basic check for comparison operators (sans uses symbolic operators only)
         # This is a bit naive if they are inside strings, but tokenize should handle it.
         for token in tokenize(text, self._file_name):
             if token.type != "OPERATOR":
                 continue
             op = token.value.lower()
-            if op in {"=", "^=", "~=", "eq", "ne"}:
+            if op in {"=", "^=", "~=", "eq", "ne", "lt", "le", "gt", "ge"}:
                 raise SansScriptError(
                     code="E_BAD_EXPR",
-                    message="Use '==' for equality and '!=' for inequality in sans scripts.",
+                    message="Use symbolic comparison operators (==, !=, <, <=, >, >=) in sans scripts.",
                     line=line_no,
                 )
 

sans/tests/test_parser_expr.py

@@ -1,6 +1,7 @@
 import pytest
 from sans.parser_expr import parse_expression_from_string
 from sans.expr import lit, col, binop, boolop, unop, call
+from sans.sans_script import SansScriptError, parse_sans_script
 
 def test_parse_literal_number():
     assert parse_expression_from_string("123") == lit(123)
@@ -41,17 +42,24 @@ def test_parse_binary_operators_precedence():
     )
 
 def test_parse_comparisons():
-    assert parse_expression_from_string("a = b") == binop("=", col("a"), col("b"))
-    assert parse_expression_from_string("a == b") == binop("=", col("a"), col("b"))
+    assert parse_expression_from_string("a == b") == binop("==", col("a"), col("b"))
+    assert parse_expression_from_string("a != b") == binop("!=", col("a"), col("b"))
     assert parse_expression_from_string("a > 10") == binop(">", col("a"), lit(10))
     assert parse_expression_from_string("x ~= y") == binop("!=", col("x"), col("y"))
-    assert parse_expression_from_string("x != y") == binop("!=", col("x"), col("y"))
     assert parse_expression_from_string("a ne b") == binop("!=", col("a"), col("b"))
-    assert parse_expression_from_string("a eq b") == binop("=", col("a"), col("b"))
+    assert parse_expression_from_string("a eq b") == binop("==", col("a"), col("b"))
     assert parse_expression_from_string("a lt b") == binop("<", col("a"), col("b"))
     assert parse_expression_from_string("a le b") == binop("<=", col("a"), col("b"))
     assert parse_expression_from_string("a gt b") == binop(">", col("a"), col("b"))
     assert parse_expression_from_string("a ge b") == binop(">=", col("a"), col("b"))
+    with pytest.raises(SansScriptError) as exc_info:
+        parse_sans_script(
+            "# sans 0.1\n"
+            "let x = a = b\n"
+            "x\n",
+            "bad_expr.sans",
+        )
+    assert exc_info.value.code == "E_BAD_EXPR"
 
 def test_parse_logical_operators_precedence():
     # if a > 1 and b < 2 works