nex renderer

examples/markdown.nex

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+
+
+  h1 Heading 8-)
+  ==============
+
+
+  h2 Heading
+  ----------
+
+
+  h3 Heading
+  ----------
+
+
+  h4 Heading
+  ----------
+
+
+  h5 Heading
+  ----------
+
+
+  h6 Heading
+  ----------
+
+
+  Horizontal Rules
+  ----------------
+
+  ----------------------------------------------------------------------------
+  ----------------------------------------------------------------------------
+  ----------------------------------------------------------------------------
+
+
+  Emphasis
+  --------
+
+  This is bold text This is bold text This is italic text This is italic text
+  Strikethrough
+
+
+  Blockquotes
+  -----------
+
+   | Blockquotes can also be nested...
+   |  | by using additional greater-than signs right next to each other...
+   |  |  | or with spaces between arrows.
+
+
+  Lists
+  -----
+
+
+  Unordered
+  ---------
+
+  + Create a list by starting a line with +, -, or *
+  - Marker character change forces new list start:
+  * Ac tristique libero volutpat at
+  + Facilisis in pretium nisl aliquet
+  - Nulla volutpat aliquam velit
+  + Very easy
+
+
+  Ordered
+  -------
+
+  1. Lorem ipsum dolor sit amet
+  2. Consectetur adipiscing elit
+  3. Integer molestie lorem at massa
+
+
+  Code
+  ----
+
+  Inline code
+
+
+  Indented code
+
+
+  01 | // Some comments
+  02 | line 1 of code
+  03 | line 2 of code
+  04 | line 3 of code
+  
+  Block code "fences"
+
+
+  01 | Sample text here...
+  
+  Syntax highlighting
+
+
+  01 | var foo = function (bar) {
+  02 |   return bar++;
+  03 | };
+  04 | 
+  05 | console.log(foo(5));
+  
+
+  Links
+  -----
+
+  link text (http://dev.nodeca.com)
+
+
+  link with title (http://nodeca.github.io/pica/demo/ "title text!")
+
+
+  Images
+  ------
+
+  Minion (https://octodex.github.com/images/minion.png) Stormtroopocat
+  (https://octodex.github.com/images/stormtroopocat.jpg "The Stormtroopocat")
+
+

src/md2txt/renderers/nex.py

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+from __future__ import annotations
+
+from functools import partial
+from typing import Any, List
+
+from ..models import BlockStyle, FrontMatter, HeadingPayload
+from ..plugins import register_renderer
+from .text import (
+    BOLD_RE,
+    CODE_STASH_RE,
+    IMAGE_RE,
+    ITALIC_RE,
+    LINK_RE,
+    STRIKETHROUGH_RE,
+    TextRenderer,
+    UNDERLINE_EM_RE,
+    UNDERLINE_STRONG_RE,
+)
+
+
+class NexRenderer(TextRenderer):
+    """Render Markdown events as plain text for the Nex protocol.
+
+    Nex has no hypertext markup for hand-authored documents at all (its one
+    special syntax, `=> URL`, is spec'd for server-auto-generated directory
+    listings, not document bodies) -- so this renderer's whole job is to
+    flatten Markdown down to plain, readable text. It reuses TextRenderer's
+    wrapping/margin/hyphenation/ASCII-art/include machinery unchanged (same
+    approach as AmaRenderer/MicronRenderer) and only overrides headings (no
+    FIGlet -- a plain setext-style underline instead, which is a readability
+    convention borrowed from Markdown itself, not a Nex spec requirement)
+    and inline formatting (emphasis markers are stripped rather than
+    translated, and links/images are inlined as "label (url)" plain prose
+    rather than footnoted or turned into `=> ` lines).
+    """
+
+    def __init__(self, frontmatter: FrontMatter, *, width: int = 80, **_: Any) -> None:
+        super().__init__(width=width, frontmatter=frontmatter)
+        # Links are inlined by `_replace_link` below, not footnoted.
+        self.links.clear()
+        self.link_indices.clear()
+
+    def _render_heading(self, payload: HeadingPayload, style: BlockStyle) -> None:
+        self._ensure_header_spacing()
+        processed_text = self._process_inline(payload.text)
+        underline_char = "=" if payload.level == 1 else "-"
+        self._emit_render(
+            partial(self._render_underlined_heading, processed_text, underline_char),
+            style,
+            stylable=True,
+        )
+
+    def _render_underlined_heading(self, text: str, underline_char: str, style: BlockStyle) -> List[str]:
+        wrapped = self._wrap_text(text, style=style)
+        output: List[str] = []
+        for line in wrapped:
+            line = line.rstrip()
+            if not line.strip():
+                output.append("")
+                continue
+            leading = len(line) - len(line.lstrip(" "))
+            underline = " " * leading + underline_char * len(line.lstrip(" "))
+            output.append(line)
+            output.append(underline)
+        output.append("")
+        return output
+
+    # Inline -------------------------------------------------------------
+
+    def _process_inline(self, text: str) -> str:
+        code_segments: List[str] = []
+
+        def stash_code(match) -> str:
+            code_segments.append(match.group(0)[1:-1])
+            return f"\u0000CODE{len(code_segments) - 1}\u0000"
+
+        text = CODE_STASH_RE.sub(stash_code, text)
+        text = STRIKETHROUGH_RE.sub(lambda m: m.group(1), text)
+        text = BOLD_RE.sub(lambda m: m.group(1), text)
+        text = UNDERLINE_STRONG_RE.sub(lambda m: m.group(1), text)
+        text = ITALIC_RE.sub(lambda m: m.group(1), text)
+        text = UNDERLINE_EM_RE.sub(lambda m: m.group(1), text)
+        text = LINK_RE.sub(self._replace_link, text)
+        text = IMAGE_RE.sub(self._replace_image, text)
+
+        for idx, code in enumerate(code_segments):
+            text = text.replace(f"\u0000CODE{idx}\u0000", code)
+        return text
+
+    @staticmethod
+    def _replace_link(match) -> str:
+        label = match.group(1).strip()
+        url = match.group(2).strip()
+        if not label or label == url:
+            return url
+        return f"{label} ({url})"
+
+    @staticmethod
+    def _replace_image(match) -> str:
+        alt = match.group(1).strip()
+        url = match.group(2).strip()
+        if not alt:
+            return url
+        return f"{alt} ({url})"
+
+
+def _nex_renderer_factory(*, frontmatter: FrontMatter, **options: Any) -> NexRenderer:
+    width = int(options.get("width", 80))
+    return NexRenderer(frontmatter, width=width)
+
+
+try:
+    register_renderer("nex", _nex_renderer_factory)
+except ValueError:
+    pass