Handle bracket/parenthesis nesting in inline links

2 files changed, 13 insertions, 7 deletions

diff --git a/docs/spec/literal.html b/docs/spec/literal.html
index 1a8e3406..8cac38c5 100644
--- a/docs/spec/literal.html
+++ b/docs/spec/literal.html
@@ -10,7 +10,7 @@
 <span class='Value'>mantissa</span>  <span class='Function'>=</span> <span class='String'>&quot;¯&quot;</span><span class='Value'>?</span> <span class='Paren'>(</span> <span class='String'>&quot;∞&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;π&quot;</span> <span class='Function'>|</span> <span class='Value'>digit</span><span class='Function'>+</span> <span class='Paren'>(</span> <span class='String'>&quot;.&quot;</span> <span class='Value'>digit</span><span class='Function'>+</span> <span class='Paren'>)</span><span class='Value'>?</span> <span class='Paren'>)</span>
 <span class='Value'>digit</span>     <span class='Function'>=</span> <span class='String'>&quot;0&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;1&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;2&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;3&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;4&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;5&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;6&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;7&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;8&quot;</span> <span class='Function'>|</span> <span class='String'>&quot;9&quot;</span>
 </pre>
-<p>The digits or arabic numerals correspond to the numbers from 0 to 9 in the conventional way (also, each corresponds to its code point value minus 48). A sequence of digits gives a natural number by evaluating it in base 10: the number is 0 for an empty sequence, and otherwise the last digit's numerical value plus ten times the number obtained from the remaining digits. The symbol <code><span class='Number'>∞</span></code> indicates infinity and <code><span class='Number'>π</span></code> indicates the ratio <a href="https://en.wikipedia.org/wiki/Pi_(mathematics">pi</a>) of a circle's circumference to its diameter (or, for modern mathematicians, the smallest positive real number at which the function <code><span class='Brace'>{</span><span class='Function'>⋆</span><span class='Number'>0j1</span><span class='Function'>×</span><span class='Value'>𝕩</span><span class='Brace'>}</span></code> attains a real part of 0). The <a href="https://aplwiki.com/wiki/High_minus">high minus</a> symbol <code><span class='Number'>¯</span></code> indicates that the number containing it is to be negated.</p>
+<p>The digits or arabic numerals correspond to the numbers from 0 to 9 in the conventional way (also, each corresponds to its code point value minus 48). A sequence of digits gives a natural number by evaluating it in base 10: the number is 0 for an empty sequence, and otherwise the last digit's numerical value plus ten times the number obtained from the remaining digits. The symbol <code><span class='Number'>∞</span></code> indicates infinity and <code><span class='Number'>π</span></code> indicates the ratio <a href="https://en.wikipedia.org/wiki/Pi_(mathematics)">pi</a> of a circle's circumference to its diameter (or, for modern mathematicians, the smallest positive real number at which the function <code><span class='Brace'>{</span><span class='Function'>⋆</span><span class='Number'>0j1</span><span class='Function'>×</span><span class='Value'>𝕩</span><span class='Brace'>}</span></code> attains a real part of 0). The <a href="https://aplwiki.com/wiki/High_minus">high minus</a> symbol <code><span class='Number'>¯</span></code> indicates that the number containing it is to be negated.</p>
 <p>When an exponent is provided (with <code><span class='Value'>e</span></code> or <code><span class='Function'>E</span></code>), the corresponding mantissa is multiplied by ten to that power, giving the value <code><span class='Value'>mantissa</span><span class='Function'>×</span><span class='Number'>10</span><span class='Function'>⋆</span><span class='Value'>exponent</span></code>. If a second component is present (using <code><span class='Value'>i</span></code> or <code><span class='Function'>I</span></code>), that component's value is multiplied by the <a href="https://en.wikipedia.org/wiki/Imaginary_unit">imaginary unit</a> <em>i</em> and added to the first component; otherwise the value is the first component's value without modification. If complex numbers are not supported, then <code><span class='Value'>i</span></code> should not be allowed in numeric literals, even when followed by 0.</p>
 <p>The above specification describes exactly a complex number with extended real components. To obtain a BQN number, each component is rounded to its nearest representative by the rules of the number system used: for IEEE 754, smallest distance, with ties rounding to the option with even mantissa.</p>
 
diff --git a/md.bqn b/md.bqn
index a15c19ad..15a4f254 100644
--- a/md.bqn
+++ b/md.bqn
@@ -261,12 +261,18 @@ Markdown ← {𝕊𝕩:1𝕊𝕩; extensions𝕊𝕩:
     ReplaceMDSub ← { ¯2 ("README"•_r_"index"∘↓∾"html"˜)⍟(("md"≡↑)∧':'∧´∘≠⊢) 𝕩 }
     ReplaceMD ← { ReplaceMDSub⌾((⊑𝕩⊐"#")⊸↑) 𝕩 }
     ProcLink ← { ∾⟨"<a href=""",(ReplaceMD 𝕩),""">",𝕨,"</a>"⟩ }
-    brak ← /∘(unused ∧ 𝕩⊸=)¨ "]()["
-    link ← (∊/⊣)´ 0‿¯1 + 2 ↑ brak
-    chains ← (⍋˜ ⊏ ⊢∾(≠𝕩)˜)` ¯1 ⌽ (<link) ∾ 2 ↓ brak
-    chains ↩ > (∧´ (∊ ∧ <⟜(≠𝕩))¨ 1 ↓ chains)⊸/¨ chains
-    linkPos ← 0 ⊏ chains
-    lInds ← 1‿0‿2‿0⊸+˘ (⥊2⊸↕)˘ ⍉ chains
+    # Find matched-depth [] and () pairs, then join adjacent ones
+    brak ← (unused ∧ 𝕩⊸=)¨ 2‿2⥊"[]()"
+    depth ← (+`-0⌊⊢)∘(-´)˘ brak
+    FindPairs ← ⟨⟩‿2 ⥊ 1⊸⊏ /˜ 2⊸⊏ ≠ (¯∞⊸Shl⊸=(∧+⊢)∞⊸Shr⊸=)∘⊏
+    pairs ← depth <∘(FindPairs⍟(0<≠))∘⍉∘(∧(⊏˜≍˘⊢)⟜∾∾˘·/≠¨∘⊢)˘ /¨brak
+    JoinPairs ← {
+      e←1+1⊏˘𝕨 ⋄ b←⊏˘𝕩 ⋄ m←(≠b)>i←b⊐e
+      (m/𝕨) ∾˘ (m/i)⊏𝕩
+    }
+    lInds ← ∧○(0<≠)◶(0‿4⥊0)‿JoinPairs´ pairs
+    linkPos ← ⊏˘ lInds
+    lInds +⎉1↩ 1‿0‿1‿0
     unused ∧↩ include ∧↩ ¬ ≠` I2M ⥊ (¯1‿1+0‿3⊸⊏)˘ lInds
     linkGroup ← 1 -˜ (1‿0⥊˜≢)⊸(/ (⊣×>)○(+`I2M) ¬⊸/) ⥊lInds
     links ← <∘ProcLink´˘ (lInds≠⊸∾2) (⊣⥊×´⊸↑) linkGroup ⊔ 𝕩