parse_lines: keep values as list of lines, join once

CHANGELOG

@@ -1,3 +1,9 @@
+2.3.1
+=====
+
+* fix quadratic parse time for values with many continuation lines (#78, regarding #77)
+* internal: ``iniconfig._parse.ParsedLine.value`` is now a list of lines
+
 2.3.0
 =====
 

src/iniconfig/_parse.py

@@ -10,7 +10,7 @@ class ParsedLine(NamedTuple):
     lineno: int
     section: str | None
     name: str | None
-    value: str | None
+    value: list[str] | None
 
 
 def parse_ini_data(
@@ -56,7 +56,7 @@ def parse_ini_data(
             if name in sections_data[section]:
                 raise ParseError(path, lineno, f"duplicate name {name!r}")
             assert value is not None
-            sections_data[section][name] = value
+            sections_data[section][name] = "\n".join(value)
 
     return sections_data, sources
 
@@ -76,7 +76,7 @@ def parse_lines(
         )
         # new value
         if name is not None and data is not None:
-            result.append(ParsedLine(lineno, section, name, data))
+            result.append(ParsedLine(lineno, section, name, [data] if data else []))
         # new section
         elif name is not None and data is None:
             if not name:
@@ -85,17 +85,10 @@ def parse_lines(
             result.append(ParsedLine(lineno, section, None, None))
         # continuation
         elif name is None and data is not None:
-            if not result:
+            value = result[-1].value if result else None
+            if value is None:
                 raise ParseError(path, lineno, "unexpected value continuation")
-            last = result.pop()
-            if last.name is None:
-                raise ParseError(path, lineno, "unexpected value continuation")
-
-            if last.value:
-                last = last._replace(value=f"{last.value}\n{data}")
-            else:
-                last = last._replace(value=data)
-            result.append(last)
+            value.append(data)
     return result
 
 

testing/test_iniconfig.py

@@ -11,36 +11,46 @@
 
 check_tokens: dict[str, tuple[str, list[PL]]] = {
     "section": ("[section]", [PL(0, "section", None, None)]),
-    "value": ("value = 1", [PL(0, None, "value", "1")]),
+    "value": ("value = 1", [PL(0, None, "value", ["1"])]),
     "value in section": (
         "[section]\nvalue=1",
-        [PL(0, "section", None, None), PL(1, "section", "value", "1")],
+        [PL(0, "section", None, None), PL(1, "section", "value", ["1"])],
     ),
+    "empty value": ("value =", [PL(0, None, "value", [])]),
     "value with continuation": (
         "names =\n Alice\n Bob",
-        [PL(0, None, "names", "Alice\nBob")],
+        [PL(0, None, "names", ["Alice", "Bob"])],
     ),
     "value with aligned continuation": (
         "names = Alice\n        Bob",
-        [PL(0, None, "names", "Alice\nBob")],
+        [PL(0, None, "names", ["Alice", "Bob"])],
+    ),
+    "continuations on several values": (
+        "a = 1\n 2\n\n 3\n[s]\nb =\n x\n y\nc = z",
+        [
+            PL(0, None, "a", ["1", "2", "3"]),
+            PL(4, "s", None, None),
+            PL(5, "s", "b", ["x", "y"]),
+            PL(8, "s", "c", ["z"]),
+        ],
     ),
     "blank line": (
         "[section]\n\nvalue=1",
-        [PL(0, "section", None, None), PL(2, "section", "value", "1")],
+        [PL(0, "section", None, None), PL(2, "section", "value", ["1"])],
     ),
     "comment": ("# comment", []),
-    "comment on value": ("value = 1", [PL(0, None, "value", "1")]),
+    "comment on value": ("value = 1", [PL(0, None, "value", ["1"])]),
     "comment on section": ("[section] #comment", [PL(0, "section", None, None)]),
     "comment2": ("; comment", []),
     "comment2 on section": ("[section] ;comment", [PL(0, "section", None, None)]),
     "pseudo section syntax in value": (
         "name = value []",
-        [PL(0, None, "name", "value []")],
+        [PL(0, None, "name", ["value []"])],
     ),
-    "assignment in value": ("value = x = 3", [PL(0, None, "value", "x = 3")]),
-    "use of colon for name-values": ("name: y", [PL(0, None, "name", "y")]),
-    "use of colon without space": ("value:y=5", [PL(0, None, "value", "y=5")]),
-    "equality gets precedence": ("value=xyz:5", [PL(0, None, "value", "xyz:5")]),
+    "assignment in value": ("value = x = 3", [PL(0, None, "value", ["x = 3"])]),
+    "use of colon for name-values": ("name: y", [PL(0, None, "name", ["y"])]),
+    "use of colon without space": ("value:y=5", [PL(0, None, "value", ["y=5"])]),
+    "equality gets precedence": ("value=xyz:5", [PL(0, None, "value", ["xyz:5"])]),
 }