feat: add Lean4 syntax highlighting support to template

paper.tex

@@ -70,10 +70,12 @@
 {
 \newminted[mlir]{tools/MLIRLexer.py:MLIRLexerOnlyOps}{customlexer, mathescape}
 \newminted[xdsl]{tools/MLIRLexer.py:MLIRLexer}{customlexer, mathescape, style=murphy}
+\newminted[lean4]{tools/Lean4Lexer.py:Lean4Lexer}{customlexer, mathescape}
 }
 {
 \newminted[mlir]{tools/MLIRLexer.py:MLIRLexerOnlyOps -x}{mathescape}
 \newminted[xdsl]{tools/MLIRLexer.py:MLIRLexer -x}{mathescape, style=murphy}
+\newminted[lean4]{tools/Lean4Lexer.py:Lean4Lexer -x}{mathescape}
 }
 \makeatother
 
@@ -130,6 +132,14 @@
 \usepackage{booktabs}
 \newcommand{\ra}[1]{\renewcommand{\arraystretch}{#1}}
 
+\usepackage[verbose]{newunicodechar}
+\newunicodechar{₁}{\ensuremath{_1}}
+\newunicodechar{₂}{\ensuremath{_2}}
+\newunicodechar{∀}{\ensuremath{\forall}}
+\newunicodechar{α}{\ensuremath{\alpha}}
+\newunicodechar{β}{\ensuremath{\beta}}
+
+
 % \circled command to print a colored circle.
 % \circled{1} pretty-prints "(1)"
 % This is useful to refer to labels that are embedded within figures.
@@ -562,6 +572,20 @@ \subsubsection{Listings} We aim to use minted to create listings as much as
 \label{lst:example}
 \end{listing}
 
+\begin{listing}[H]
+\begin{lean4}
+theorem funext {f₁ f₂ : ∀ (x : α), β x}
+  (h : ∀ x, f₁ x = f₂ x) : f₁ = f₂ := by
+  show extfunApp (Quotient.mk' f₁) = 
+       extfunApp (Quotient.mk' f₂)
+  apply congrArg
+  apply Quotient.sound
+  exact h
+\end{lean4}
+\caption{A simple Lean4 code example, taken from
+  \url{https://lean-lang.org/lean4/doc/syntax\_highlight\_in\_latex.html\#example-with-minted}.}
+\end{listing}
+
 The syntax highlighting also works for xDSL-like IRs. Notice that different
 minted styles can be used for different environments. The xDSL environment uses
 the murphy-style in this case, whereas the MLIR version applies the

tools/Lean4Lexer.py

@@ -0,0 +1,100 @@
+# -*- coding: utf-8 -*-
+"""
+    pygments.lexers.theorem
+    ~~~~~~~~~~~~~~~~~~~~~~~
+
+    Lexers for theorem-proving languages.
+
+    :copyright: Copyright 2006-2017 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+
+from pygments.lexer import RegexLexer, default, words
+from pygments.token import Text, Comment, Operator, Keyword, Name, String, \
+    Number, Punctuation, Generic
+
+__all__ = ['Lean4Lexer']
+
+class Lean4Lexer(RegexLexer):
+    """
+    For the `Lean 4 <https://github.com/leanprover/lean4>`_
+    theorem prover.
+
+    .. versionadded:: 2.0
+    """
+    name = 'Lean4'
+    aliases = ['lean4']
+    filenames = ['*.lean']
+    mimetypes = ['text/x-lean']
+
+    flags = re.MULTILINE | re.UNICODE
+
+    keywords1 = (
+        'import', 'abbreviation', 'opaque_hint', 'tactic_hint', 'definition',
+        'renaming', 'inline', 'hiding', 'parameter', 'lemma', 'variable',
+        'theorem', 'axiom', 'inductive', 'structure', 'universe', 'alias',
+        'help', 'options', 'precedence', 'postfix', 'prefix',
+        'infix', 'infixl', 'infixr', 'notation', '#eval',
+        '#check', '#reduce', '#exit', 'coercion', 'end', 'private', 'using', 'namespace',
+        'including', 'instance', 'section', 'context', 'protected', 'expose',
+        'export', 'set_option', 'extends', 'open', 'example',
+        'constant', 'constants', 'print', 'opaque', 'reducible', 'irreducible',
+        'def', 'macro', 'elab', 'syntax', 'macro_rules', 'reduce', 'where',
+        'abbrev', 'noncomputable', 'class', 'attribute', 'synth', 'mutual',
+    )
+
+    keywords2 = (
+        'forall', 'fun', 'Pi', 'obtain', 'from', 'have', 'show', 'assume',
+        'take', 'let', 'if', 'else', 'then', 'by', 'in', 'with', 'begin',
+        'proof', 'qed', 'calc', 'match', 'nomatch', 'do', 'at',
+    )
+
+    keywords3 = (
+        # Sorts
+        'Type', 'Prop', 'Sort',
+    )
+
+    operators = (
+        u'!=', u'#', u'&', u'&&', u'*', u'+', u'-', u'/', u'@', u'!', u'`',
+        u'-.', u'->', u'.', u'..', u'...', u'::', u':>', u';', u';;', u'<',
+        u'<-', u'=', u'==', u'>', u'_', u'|', u'||', u'~', u'=>', u'<=', u'>=',
+        u'/\\', u'\\/', u'∀', u'Π', u'λ', u'↔', u'∧', u'∨', u'≠', u'≤', u'≥',
+        u'¬', u'⁻¹', u'⬝', u'▸', u'→', u'∃', u'ℕ', u'ℤ', u'≈', u'×', u'⌞',
+        u'⌟', u'≡', u'⟨', u'⟩',
+    )
+
+    punctuation = (u'(', u')', u':', u'{', u'}', u'[', u']', u'⦃', u'⦄',
+                   u':=', u',')
+
+    tokens = {
+        'root': [
+            (r'\s+', Text),
+            (r'/-', Comment, 'comment'),
+            (r'--.*?$', Comment.Single),
+            (words(keywords1, prefix=r'\b', suffix=r'\b'), Keyword.Namespace),
+            (words(keywords2, prefix=r'\b', suffix=r'\b'), Keyword),
+            (words(keywords3, prefix=r'\b', suffix=r'\b'), Keyword.Type),
+            (words(operators), Name.Builtin.Pseudo),
+            (words(punctuation), Operator),
+            (u"[A-Za-z_\u03b1-\u03ba\u03bc-\u03fb\u1f00-\u1ffe\u2100-\u214f]"
+             u"[A-Za-z_'\u03b1-\u03ba\u03bc-\u03fb\u1f00-\u1ffe\u2070-\u2079"
+             u"\u207f-\u2089\u2090-\u209c\u2100-\u214f0-9]*", Name),
+            (r'\d+', Number.Integer),
+            (r'"', String.Double, 'string'),
+            (r'[~?][a-z][\w\']*:', Name.Variable)
+        ],
+        'comment': [
+            # Multiline Comments
+            (r'[^/-]', Comment.Multiline),
+            (r'/-', Comment.Multiline, '#push'),
+            (r'-/', Comment.Multiline, '#pop'),
+            (r'[/-]', Comment.Multiline)
+        ],
+        'string': [
+            (r'[^\\"]+', String.Double),
+            (r'\\[n"\\]', String.Escape),
+            ('"', String.Double, '#pop'),
+        ],
+    }