feat(chunks): aggiunge parser.py con markdown-it-py

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

chunks/parser.py

@@ -0,0 +1,16 @@
+from __future__ import annotations
+from markdown_it import MarkdownIt
+from markdown_it.token import Token
+
+
+def parse(source: str) -> tuple[list[Token], list[str]]:
+    """Parsa Markdown in token stream con source map.
+
+    Returns:
+        tokens: lista Token con .map = [start_line, end_line] (0-indexed, end escluso)
+        lines:  righe sorgente (0-indexed) per ricostruzione testo esatto
+    """
+    md = MarkdownIt().enable("table")
+    tokens = md.parse(source)
+    lines = source.splitlines()
+    return tokens, lines

tests/chunks/test_parser.py

@@ -0,0 +1,46 @@
+from chunks.parser import parse
+
+
+def test_parse_returns_tokens_and_lines():
+    md = "# Titolo\n\nParagrafo.\n"
+    tokens, lines = parse(md)
+    assert len(tokens) > 0
+    assert lines[0] == "# Titolo"
+    assert lines[2] == "Paragrafo."
+
+
+def test_tokens_have_source_map():
+    md = "# Titolo\n\nParagrafo.\n"
+    tokens, lines = parse(md)
+    heading = next(t for t in tokens if t.type == "heading_open")
+    assert heading.map is not None
+    assert heading.map[0] == 0
+
+
+def test_parse_code_fence():
+    md = "# T\n\n```python\ncodice\n```\n"
+    tokens, lines = parse(md)
+    fence = next((t for t in tokens if t.type == "fence"), None)
+    assert fence is not None
+    assert "codice" in fence.content
+
+
+def test_parse_table():
+    md = "| A | B |\n|---|---|\n| 1 | 2 |\n"
+    tokens, lines = parse(md)
+    types = [t.type for t in tokens]
+    assert "table_open" in types
+
+
+def test_parse_list():
+    md = "- item 1\n- item 2\n"
+    tokens, lines = parse(md)
+    types = [t.type for t in tokens]
+    assert "bullet_list_open" in types
+
+
+def test_lines_preserves_source():
+    md = "Riga 1\nRiga 2\nRiga 3\n"
+    _, lines = parse(md)
+    assert lines[0] == "Riga 1"
+    assert lines[1] == "Riga 2"