Wrap and format Content lazily to stop at the needed height

evidence/native-content-height-consumption-20261005/SCOPE.md

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+# Bound native Content formatting at its original render height
+
+Base: Text68/69 merged c1bcc8d33164553432f2a718eeddec1a1ffa4a5f.
+
+Existing Content.render_strips calls its original _wrap_and_format owner for
+ALL paragraphs / _FormattedLine resources before slicing that result to the
+requested height. Visual's render height already declares which prefix is
+needed; RichVisual bounds its own segment stream with islice, while Content
+constructs the unused suffix first.
+
+Make the existing Content formatting algorithm an iterator. Migrate its entire
+consumer family: complete wrap and height measurement consume all; bounded
+strip rendering consumes its required prefix; original negative slicing stays
+complete before slicing. Public Visual/render_strips/list and wrap/list
+contracts, source selection/link/wide-cell metadata and original Content.split
+resource remain unchanged. Delete the unused complete formatted-result list.
+No new class, cache, map, timer, flag, alternate renderer or Toad implementation.
+
+The initial published iterator source was
+71e8c7fd4486b772252dafe7556b91e23a08fab9 (7 additions / 10 deletions).
+The same owner now also yields each wrapped line directly: no complete
+per-paragraph formatting list, intermediate truncated-content list, or
+throwaway _FormattedLine solely for its content field. Original loop_last
+supplies the last-line justification fact at construction instead of mutating
+the last member of a completed list. Current production delta is 23 additions /
+34 deletions in one file. Unrequested wrapped suffixes no longer construct
+formatted lines or apply their truncation/padding. Original Content.split and
+divide still acquire source slices and wrapping boundaries; neither is claimed
+eliminated or height bounded.
+
+The before AST covers 249 native production files / 460 native test files and
+288 Toad production files / 397 test files / 41 tools with zero parse omissions.
+It identifies one formatter declaration, three native production readers,
+two native test count readers plus one monkeypatch, and ONE extra Toad private
+reader: PathContent.render_strips in path_search.py. That reader slices the
+formatter result and must migrate before qualification. Heisenberg owns this
+Toad change, preserving original path shortening, nowrap/clip/tab8/left/zero
+padding and RenderOptions through Content.render_strips. PreparedDiffLine
+inherits the original rendering implementation without an override.
+
+ONE final native source batch executed at
+81ca92b137e3070b31abb5146b7bae6f8043e228, production tree
+90f78e605a8dc1470d1de8c19220ab4b26474706: 348 PASS / 0 FAIL in 0.76s
+(pytest), controller 2.499691362027079s, terminal 0. Original Content wrapping,
+complete height measurement (including no available width), and public
+bounded/full/negative rendering preserve strip cells, link/wide-cell/selection
+metadata and post styles. Original log SHA256:
+9c92eb8034b308320e4b038c3781be785dd0f3a557acc06d39b237548b1125a4.
+Heisenberg published PathContent delegation at
+1fbe1f09b80dec9a809609edaeafc6ddb5a661a2 (Toad463); final AST finds zero
+Toad private formatter readers. The complete native producer read then found a
+caller contract defect: Visual.to_strips supplies widget.styles, not a dict,
+and Styles/RenderStyles has no mapping-union operation. PathContent currently
+unions that resource with its four fixed rules. Heisenberg corrected that original four-rule leaf policy directly at
+a4d7cb17435470edd1276360d9c9a26593c4a031 while preserving all other RenderOptions fields.
+Final source AST retains zero Toad private formatter readers, one public
+Content delegation, and no parse omissions. Unchanged test/tool AST is carried
+by exact original Git tree identity; no repeated parse or checks are claimed.
+The original 1fbe counterexample remains recorded as source evidence, not an
+executed UI failure. Complete declared source family and native source controls
+are closed; the changed installed caller/frame journey remains unqualified. No installed App/frame/motion qualification
+exists for Text70. Unregistered external private readers and runtime rebinding
+are not proved by the AST.
+
+The original recorded59.605 RichVisual stack does NOT identify Content or its
+widget/invalidation cause. This independent unused-resource source finding is
+not an attribution of that sample, a CPU share or a measured speedup.
+
+AST complete production/dependency/test caller and override evidence precedes
+editing; coherent source change then one affected control batch and joined
+installed meaningful frame check. No App/build/installed/SDK/provider/media
+purpose exists now. Text68/69 wheel a0c2 and qualification stay frozen.

evidence/native-content-height-consumption-20261005/after.json

@@ -0,0 +1,276 @@
+{
+  "roots": [
+    {
+      "repository": "/home/ts/wt/textual-native-subtree-strips-20261002",
+      "head": "325a912635f55f6ec15b8365530a66c04edaf1ad",
+      "root": "src/textual",
+      "parsed": 249,
+      "omitted": []
+    },
+    {
+      "repository": "/home/ts/wt/textual-native-subtree-strips-20261002",
+      "head": "325a912635f55f6ec15b8365530a66c04edaf1ad",
+      "root": "tests",
+      "parsed": 460,
+      "omitted": []
+    },
+    {
+      "repository": "/home/ts/wt/toad-viewport-raster-cpu-continuation-20261001",
+      "head": "a4d7cb17435470edd1276360d9c9a26593c4a031",
+      "root": "src/toad",
+      "parsed": 288,
+      "omitted": []
+    },
+    {
+      "repository": "/home/ts/wt/toad-viewport-raster-cpu-continuation-20261001",
+      "head": "1fbe1f09b80dec9a809609edaeafc6ddb5a661a2",
+      "root": "tests",
+      "parsed": 397,
+      "omitted": []
+    },
+    {
+      "repository": "/home/ts/wt/toad-viewport-raster-cpu-continuation-20261001",
+      "head": "1fbe1f09b80dec9a809609edaeafc6ddb5a661a2",
+      "root": "tools",
+      "parsed": 41,
+      "omitted": []
+    }
+  ],
+  "formatter_sites": [
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 1724,
+      "node": "ClassDef",
+      "name": "_FormattedLine",
+      "source": "class _FormattedLine:"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 638,
+      "node": "FunctionDef",
+      "name": "_wrap_and_format",
+      "source": "    def _wrap_and_format("
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 650,
+      "node": "Name",
+      "name": "_FormattedLine",
+      "source": "_FormattedLine"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 1532,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 1552,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 736,
+      "node": "Name",
+      "name": "_FormattedLine",
+      "source": "_FormattedLine"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 736,
+      "node": "Attribute",
+      "name": "_wrap_and_format",
+      "source": "self._wrap_and_format"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 1011,
+      "node": "Attribute",
+      "name": "_wrap_and_format",
+      "source": "self._wrap_and_format"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 1535,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 1537,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 691,
+      "node": "Name",
+      "name": "_FormattedLine",
+      "source": "_FormattedLine"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 707,
+      "node": "Name",
+      "name": "_FormattedLine",
+      "source": "_FormattedLine"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 618,
+      "node": "Attribute",
+      "name": "_wrap_and_format",
+      "source": "self.without_spans._wrap_and_format"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/content.py",
+      "line": 688,
+      "node": "Name",
+      "name": "_FormattedLine",
+      "source": "_FormattedLine"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/document/_wrapped_document.py",
+      "line": 197,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/document/_wrapped_document.py",
+      "line": 212,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/document/_wrapped_document.py",
+      "line": 267,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/widgets/_log.py",
+      "line": 231,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/widgets/_log.py",
+      "line": 235,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/widgets/_log.py",
+      "line": 239,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/widgets/_log.py",
+      "line": 240,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "src/textual",
+      "path": "src/textual/widgets/_log.py",
+      "line": 233,
+      "node": "Name",
+      "name": "new_lines",
+      "source": "new_lines"
+    },
+    {
+      "root": "tests",
+      "path": "tests/test_content_measurement_projection.py",
+      "line": 17,
+      "node": "Constant",
+      "name": "_wrap_and_format",
+      "source": "\"_wrap_and_format\""
+    },
+    {
+      "root": "tests",
+      "path": "tests/test_content_measurement_projection.py",
+      "line": 16,
+      "node": "Attribute",
+      "name": "_wrap_and_format",
+      "source": "content.without_spans._wrap_and_format"
+    },
+    {
+      "root": "tests",
+      "path": "tests/test_content_measurement_projection.py",
+      "line": 25,
+      "node": "Attribute",
+      "name": "_wrap_and_format",
+      "source": "content.without_spans._wrap_and_format"
+    }
+  ],
+  "limits": "Syntactic source evidence only; runtime rebinding and unregistered external private readers unresolved. Native source/tests AST is reused from identical 325a source; Toad source successor is pinned independently. No installed frame, motion or CPU attribution.",
+  "toad_private_formatter_readers": [],
+  "toad_public_content_delegations": [
+    {
+      "root": "src/toad",
+      "path": "src/toad/widgets/path_search.py",
+      "line": 70,
+      "source": "Content.render_strips(\n            line,\n            width,\n            height,\n            style,\n            replace(\n                options,\n                rules={\n                    \"text_wrap\": \"nowrap\",\n                    \"text_overflow\": \"clip\",\n                    \"text_align\": \"left\",\n                    \"line_pad\": 0,\n                },\n            ),\n        )"
+    }
+  ],
+  "path_contract_counterexample": {
+    "source": "1fbe1f09b80dec9a809609edaeafc6ddb5a661a2",
+    "producer": "src/textual/visual.py Visual.to_strips constructs RenderOptions with widget.styles; src/textual/widgets/_option_list.py uses that path",
+    "failure": "Styles/RenderStyles supports get but not mapping union; PathContent options.rules | dict is not supported by the real producer",
+    "correction_owner": "Heisenberg, Toad463",
+    "required_correction": "Preserve the four original fixed render rules directly; leave the other RenderOptions fields unchanged. No native change or reproduction required.",
+    "corrected_source_head": "a4d7cb17435470edd1276360d9c9a26593c4a031",
+    "correction": "Original four fixed Path render rules are supplied directly in replace(options); native Styles is no longer used as a mapping-union operand."
+  },
+  "source_preserving_transitions": [
+    {
+      "root": "tests",
+      "parsed_at": "1fbe1f09b80dec9a809609edaeafc6ddb5a661a2",
+      "source_head": "a4d7cb17435470edd1276360d9c9a26593c4a031",
+      "tree": "72d50efa1f3c1fe3379fbff2981313fefddb9a1a",
+      "source_equal": true
+    },
+    {
+      "root": "tools",
+      "parsed_at": "1fbe1f09b80dec9a809609edaeafc6ddb5a661a2",
+      "source_head": "a4d7cb17435470edd1276360d9c9a26593c4a031",
+      "tree": "5f291b2f613803e0b1596581215557f35c65c8d6",
+      "source_equal": true
+    }
+  ]
+}