1 files changed, 29 insertions, 0 deletions
diff --git a/tutorial/evalexp.bqn b/tutorial/evalexp.bqn
new file mode 100644
index 00000000..304301e5
--- /dev/null
+++ b/tutorial/evalexp.bqn
@@ -0,0 +1,29 @@
+wh ← 10.75‿24
+pad← wh×1.5‿1
+t ← 10
+
+ps ← >⟨"stroke"‿"#585552","style"‿"fill:none","stroke-width"‿"2"⟩
+rc ← >⟨"class"‿"code","stroke-width"‿"1","rx"‿"12"⟩
+gr ← "g" Attr >⟨"font-family"‿"BQN,monospace", "font-size"‿"18px"⟩
+
+DrawEval←{
+  ix←𝕩⊏˜i←/𝕩≠' '
+  f←0=b←-˝p←"()"=⌜ix
+  l←<⟜«fn←ix∊"+-×÷⋆√"
+  g←⍋+`b
+  ei←¯1∾˜b{((𝕨<0)/𝕩)⌾((𝕨>0)⊸/)𝕩}○(g⊸⊏)»+`f
+  o←ei⊏˜f/↕∘≠⊸-⌾(g⊸⊏)(1+»l)(⊢+fn×-)1-2×l
+  g⊏˜↩⍋g⊏l
+  rev←⍋+`¯1↓(¯1∾g)(⊣⍋⊸⊏⊏˜⟜⍋¬⊏˜)⍋+`⊸+1∾g⊏l∨⊏p
+  m←1+⌈´d←+`⊸×⌾(rev⊸⊏)fn
+
+  pt ← f/⍉> wh×⟨i,d⟩
+  off← (o ⊏ ∾⟜(wh×¯1‿m))⊸- pt
+  pd ← pt (<(wh×0.6‿0.1)⊸+)⊸∾⟜⌽˘ off
+  dim← (wh×⟨≠𝕩,2+m⟩)+2‿0×pad
+  (512‿0⊸⌈⊸(⊣∾˜(t+pad)-˜-˜÷2˙)dim+2×t) SVG gr Enc ∾⥊¨⟨
+    <"rect" Elt rc∾(Pos-pad)∾"width"‿"height"≍˘FmtNum¨dim
+    <"text" Enc Highlight 𝕩
+    (<"path" Elt ps∾"d"≍○<·∾"Mvh"∾⟜Fmt¨⊢)˘ pd
+  ⟩
+}