fixed #254: Improve LaTeX parsing for interval notation and enhance Mandelbrot/Julia compilation

Author: arnog

CHANGELOG.md

@@ -1,3 +1,34 @@
+### [Unreleased]
+
+#### Fixed
+
+- **LaTeX parsing: interval notation with `\lbrack`/`\lparen`** — parsing
+  `\lbrack5,7)` or `\left\lbrack5,7\right)` now correctly produces an
+  `Interval` expression. Previously, when the open delimiter was a LaTeX
+  command (e.g., `\lbrack`), the parser incorrectly required the close
+  delimiter to also be a LaTeX command (e.g., `\rparen` instead of `)`),
+  causing mismatched-delimiter intervals to fail.
+
+#### Added
+
+- **High-precision Mandelbrot/Julia compilation** — the GPU compilation targets
+  (GLSL, WGSL) now support three precision tiers for fractal rendering, selected
+  automatically based on viewport hints:
+  - **Single float** (zoom < 10^6x): existing implementation, no overhead
+  - **Emulated double** (zoom 10^6x–10^14x): double-single (float-float)
+    arithmetic using Dekker/Knuth algorithms, ~48-bit mantissa from two 32-bit
+    floats
+  - **Perturbation theory** (zoom > 10^14x): reference orbit computed on CPU at
+    arbitrary precision via `BigDecimal`, GPU iterates only the small delta from
+    the reference, with glitch detection and single-float rebase fallback
+- **Viewport-aware compile API** — `compile()` accepts optional
+  `hints: { viewport: { center, radius } }`. The compiler auto-selects the
+  precision strategy and returns `staleWhen` thresholds for cheap staleness
+  checking by the plot engine.
+- **`CompilationResult` extensions** — new optional fields: `staleWhen` (plain
+  data staleness predicate), `uniforms` (scalar shader uniforms), `textures`
+  (typed texture data with format/dimensions for GPU upload).
+
 ### 0.55.3 _2026-03-05_
 
 #### Improved
@@ -23,8 +54,8 @@
     integer-typed
   - `Abs` is a no-op when the operand is provably non-negative
   - `Power(x, 2)` only expands to `(x * x)` for simple operands (symbols,
-    literals) — function calls like `Power(Sin(x), 2)` use `pow`/`Math.pow`
-    to avoid duplicate evaluation
+    literals) — function calls like `Power(Sin(x), 2)` use `pow`/`Math.pow` to
+    avoid duplicate evaluation
   - Integer `Mod` with non-negative dividend uses plain `%` instead of the
     Euclidean double-mod formula
   - GPU variable declarations infer `i32`/`int` type for integer-typed locals

src/compute-engine/latex-syntax/parse.ts

@@ -914,23 +914,20 @@ export class _Parser implements Parser {
           this.index = start;
           return false;
         }
-        // Check if we matched a LaTeX command variant (e.g., \lbrack for [)
-        const matchedToken = this.nextToken();
-        const useLatexCommand = matchedToken.startsWith('\\');
+        this.nextToken();
 
         // Consume closing brace if we had a braced delimiter \mathopen{(}
         if (hasBracedDelimiter && !this.match('<}>')) {
           this.index = start;
           return false;
         }
 
-        // Find the corresponding close token variant
-        const closeTokens = DELIMITER_SHORTHAND[close[0] as string] ?? [
-          close[0],
-        ];
-        const closeToken = (closeTokens.find((t) =>
-          useLatexCommand ? t.startsWith('\\') : !t.startsWith('\\')
-        ) ?? closeTokens[0]) as LatexToken;
+        // Use the close token exactly as specified in the trigger.
+        // The matchfix entries already enumerate all delimiter combinations
+        // (e.g., [/), \lbrack/), [/\rparen, \lbrack/\rparen for intervals),
+        // so we should not transform the close token based on what format
+        // the open token was in.
+        const closeToken = close[0] as LatexToken;
 
         // Build the close boundary: for braced form, expect \mathclose{)}
         const closeBoundary = closePrefix

test/playground.ts

@@ -18,9 +18,15 @@ import {
 const ce = new ComputeEngine();
 const engine = ce;
 
-const mandelbrot = parse('1+\\operatorname{Mandelbrot}(x+yi,200)');
-// console.log(compile(mandelbrot, { to: 'glsl' }).run?.({ x: 0.355, y: 0.355 }));
-console.log(compile(mandelbrot, { to: 'glsl' }).code);
+console.log(parse('x + 2 = \\square').json);
+console.log(parse('x + 2 = \\placeholder').json);
+
+parse('[5,7)');
+// -> ok, `["Interval", 5, ["Open", 7]]`
+parse('\\lbrack5,7)');
+// -> error
+parse('\\left\\lbrack5,7\\right)');
+// -> error
 
 // 1. sin(theta)**2 + cos(theta)**2 → 1 — Clean trig identity, but too simple.
 // 2. (alpha**2 - beta**2) / (alpha - beta) → didn't simplify. Engine doesn't cancel the