Typst extension

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
 
 * When strip=True in code/text, then text steps line are rstripped
+* "typst" extension for writing mathematical expressions
 
 # v0.21.2
 

nelsie/python/nelsie/box.py

@@ -6,6 +6,7 @@
     ImageContent,
     check_image_path_or_data,
     normalize_and_watch_image_path,
+    normalize_image_path,
 )
 from .steps import (
     Sn,
@@ -228,12 +229,16 @@ def image(
         *,
         enable_steps: Sv[bool] = True,
         shift_steps: int = 0,
+        watch=True,
         **box_args,
     ):
         sn_check(path_or_data, check_image_path_or_data)
         sv_check(enable_steps, check_is_bool)
         sv_check(shift_steps, check_is_int)
-        path_or_data = sn_map(path_or_data, normalize_and_watch_image_path)
+        if watch:
+            path_or_data = sn_map(path_or_data, normalize_and_watch_image_path)
+        else:
+            path_or_data = sn_map(path_or_data, normalize_image_path)
         box = self.box(**box_args)
         box._content = ImageContent(path_or_data, enable_steps, shift_steps)
         return box

nelsie/python/nelsie/helpers/typst.py

@@ -0,0 +1,54 @@
+import subprocess
+import hashlib
+import os
+
+
+class Typst:
+    def __init__(self, typst_path="typst", cache_path="./typst_cache"):
+        cache_path = os.path.abspath(cache_path)
+        if not os.path.isdir(cache_path):
+            os.makedirs(cache_path)
+        self.typst_path = typst_path
+        self.cache_path = cache_path
+
+        self.default_header = self.get_header()
+        self.version = self._call_typst(["--version"])
+        hasher = hashlib.sha1()
+        hasher.update(self.version)
+        self.hasher = hasher
+        self.generated = set()
+
+    def _call_typst(self, args: list[str]):
+        r = subprocess.run([self.typst_path, *args], check=True, stdout=subprocess.PIPE)
+        return r.stdout
+
+    def get_header(self, width="auto", height="auto", margin_x="0pt", margin_y="0pt"):
+        return f"#set page(width: {width}, height: {height}, margin: (x: {margin_x}, y: {margin_y}))\n"
+
+    def get_path(self, text: str, use_header: bool = True):
+        if use_header:
+            text = f"{self.default_header}\n{text}"
+        hasher = self.hasher.copy()
+        hasher.update(text.encode())
+        hex = hasher.digest().hex()
+        self.generated.add(hex)
+        output_path = os.path.join(self.cache_path, f"{hex}.svg")
+        if os.path.isfile(output_path):
+            return output_path
+        input_path = os.path.join(self.cache_path, f"{hex}.typ")
+        with open(input_path, "w") as f:
+            f.write(text)
+        self._call_typst(["compile", "--format=svg", input_path])
+        return output_path
+
+    def render(self, slide, text: str, use_header: bool = True, **kwargs):
+        kwargs.setdefault("watch", False)
+        slide.image(self.get_path(text, use_header), **kwargs)
+
+    def clean_cache(self):
+        for path in os.listdir(self.cache_path):
+            if not path.endswith(".typ") and not path.endswith(".svg"):
+                continue
+            base = path[:-4]
+            if base not in self.generated:
+                os.unlink(os.path.join(self.cache_path, path))

nelsie/python/nelsie/image.py

@@ -48,6 +48,12 @@ def normalize_and_watch_image_path(path):
     return path
 
 
+def normalize_image_path(path):
+    if isinstance(path, str):
+        path = os.path.abspath(path)
+    return path
+
+
 def _put_into_shared_data(
     path_or_data: PathOrImageData | None, content, shared_data, steps
 ):