From f935c4a9b692e4fdbfe0a7537b68de8d57e23b9e Mon Sep 17 00:00:00 2001
From: Herman Sletmoen <hermansletmoen@gmail.com>
Date: Fri, 13 Dec 2024 15:19:02 +0100
Subject: [PATCH] Override default variable latexification with custom [latex =
 ...] field

---
 src/latexify_recipes.jl | 29 +++++++++++++++++++++--------
 src/variable.jl         |  6 +++---
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/latexify_recipes.jl b/src/latexify_recipes.jl
index 58dcdd3b4..7b0cd762a 100644
--- a/src/latexify_recipes.jl
+++ b/src/latexify_recipes.jl
@@ -52,8 +52,12 @@ recipe(n) = latexify_derivatives(cleanup_exprs(_toexpr(n)))
     cdot --> false
     fmt --> FancyNumberFormatter(5)
     index --> :subscript
-    snakecase --> true
-    safescripts --> true
+
+    # Prevent Latexify.jl from interfering if variable has custom [latex = ...] field (it should escape its own underscores etc.)
+    custom = hasmetadata(unwrap(n), VariableLatex)
+    snakecase --> !custom
+    safescripts --> !custom
+    function_name --> false
 
     return recipe(n)
 end
@@ -191,13 +195,22 @@ function _toexpr(O)
             return frac_expr
         end
     end
-    if issym(O) 
-        sym = string(nameof(O))
-        sym = replace(sym, NAMESPACE_SEPARATOR => ".")
-        if length(sym) > 1
-            sym = string("\\mathtt{", sym, "}")
+    if issym(O)
+        name = string(nameof(O))
+
+        # If given, use custom [latex = ...] option for the variable name (does not affect subsystem names)
+        # Otherwise fall back to a sane default, where multi-letter variables are rendered with a fixed width font
+        name = replace(name, NAMESPACE_SEPARATOR => '.')
+        if hasmetadata(O, VariableLatex)
+            seppos = findlast('.', name)
+            sysname = isnothing(seppos) ? "" : "\\mathtt{$(name[begin:seppos])}" # always \mathtt system names (consistent with multi-letter vars)
+            varname = getmetadata(O, VariableLatex) # override
+            name = string(sysname, varname)
+        elseif length(name) > 1
+            name = "\\mathtt{$name}"
         end
-        return Symbol(sym)
+
+        return Symbol(name)
     end
     !iscall(O) && return O
 
diff --git a/src/variable.jl b/src/variable.jl
index 489a072de..c4b60f82c 100644
--- a/src/variable.jl
+++ b/src/variable.jl
@@ -17,6 +17,7 @@ const IndexMap = Dict{Char,Char}(
 abstract type AbstractVariableMetadata end
 struct VariableDefaultValue <: AbstractVariableMetadata end
 struct VariableSource <: AbstractVariableMetadata end
+struct VariableLatex <: AbstractVariableMetadata end
 
 function recurse_and_apply(f, x)
     if symtype(x) <: AbstractArray
@@ -252,9 +253,8 @@ function construct_vars(macroname, v, type, call_args, val, prop, transform, isr
     lhs, :($lhs = $rhs)
 end
 
-function option_to_metadata_type(::Val{opt}) where {opt}
-    throw(Base.Meta.ParseError("unknown property type $opt"))
-end
+option_to_metadata_type(::Val{:latex}) = VariableLatex
+option_to_metadata_type(::Val{opt}) where {opt} = throw(Base.Meta.ParseError("unknown property type $opt"))
 
 function setprops_expr(expr, props, macroname, varname)
     expr = :($setmetadata($expr, $VariableSource, ($(Meta.quot(macroname)), $varname,)))