feat: 完善 SCDM-first 参数化编辑交付版

step_editor/relation_formulas.py

@@ -10,6 +10,18 @@ from typing import Callable, Iterable
 RELATION_REF_PATTERN = re.compile(
     r"\b(?P<kind>Face|Edge)(?P<object_id>\d+)\.(?P<parameter>[A-Za-z0-9_\u4e00-\u9fff]+)\b"
 )
+RELATION_UNIT_LITERAL_PATTERN = re.compile(
+    r"(?<![A-Za-z0-9_.])(?P<number>(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?)\s*(?P<unit>mm|毫米|cm|厘米|m|米)\b",
+    re.IGNORECASE,
+)
+RELATION_UNIT_MULTIPLIERS = {
+    "mm": 1.0,
+    "毫米": 1.0,
+    "cm": 10.0,
+    "厘米": 10.0,
+    "m": 1000.0,
+    "米": 1000.0,
+}
 
 
 class RelationFormulaError(ValueError):
@@ -112,7 +124,10 @@ def parse_relation_formula(text: str) -> RelationFormula:
         references.append(_ref_from_match(match))
         return f"__ref{len(references) - 1}"
 
+    # 用户输入的 Face85.直径 不能直接丢给 eval；先替换成内部占位符，
+    # 后面只允许这些占位符和白名单 AST 节点参与计算。
     safe_expression = RELATION_REF_PATTERN.sub(replace_ref, expression)
+    safe_expression = _replace_unit_literals(safe_expression)
     try:
         tree = ast.parse(safe_expression, mode="eval")
     except SyntaxError as exc:
@@ -136,6 +151,8 @@ def evaluate_relation_formula(
         namespace[f"__ref{index}"] = _coerce_formula_value(value_resolver(ref))
     code = compile(formula.safe_expression, "<relation-formula>", "eval")
     try:
+        # 这里仍然使用 Python 表达式能力，但 builtins 为空，AST 也已校验过。
+        # 关系式只承担参数求值，不允许调用函数、访问属性或执行任意代码。
         value = eval(code, {"__builtins__": {}}, namespace)
     except ZeroDivisionError as exc:
         raise RelationFormulaError("关系式中出现除以 0。") from exc
@@ -158,6 +175,8 @@ def validate_relation_formula_graph(formulas: Iterable[RelationFormula]) -> None
         reference_tokens = [ref.token for ref in formula.references]
         if target_token in reference_tokens:
             raise RelationFormulaError(f"关系式不能引用自身：{target_token}。")
+        # 只把“由其它公式控制的参数”纳入依赖图；普通测量值由模型/cache 提供，
+        # 不参与循环依赖判断。
         graph[target_token] = [ref_token for ref_token in reference_tokens if ref_token in target_tokens]
 
     visit_state: dict[str, str] = {}
@@ -213,6 +232,18 @@ def _ref_from_match(match: re.Match[str]) -> ObjectParameterRef:
     )
 
 
+def _replace_unit_literals(expression: str) -> str:
+    def replace(match: re.Match[str]) -> str:
+        number_text = str(match.group("number"))
+        unit = str(match.group("unit"))
+        multiplier = RELATION_UNIT_MULTIPLIERS.get(unit) or RELATION_UNIT_MULTIPLIERS.get(unit.lower())
+        if multiplier is None:
+            raise RelationFormulaError(f"不支持的单位：{unit}")
+        return f"({number_text}*{multiplier:.12g})"
+
+    return RELATION_UNIT_LITERAL_PATTERN.sub(replace, expression)
+
+
 def _validate_expression_tree(tree: ast.AST, ref_count: int) -> None:
     allowed = (
         ast.Expression,