Improvements to fontification

1. correctly fontify escape sequences and regex strings;

2. correctly fontify tuple assigments;

3. make function definition name fontification significantly simpler and
   more robust, fontify more obscure variants correctly.

Author: dhanak

julia-ts-mode.el

@@ -144,23 +144,38 @@ Otherwise, the indentation is:
   (treesit-font-lock-rules
    :language 'julia
    :feature 'assignment
-   `((assignment :anchor [(identifier) (operator)] @font-lock-variable-name-face)
+   `(;; regular variable assignments
      (assignment
       :anchor
-      (field_expression
-       value: (identifier) "." (identifier) @font-lock-variable-name-face))
-     (assignment (open_tuple (identifier) @font-lock-variable-name-face))
+      [(identifier) (operator)] @font-lock-variable-name-face)
+     (assignment
+      :anchor
+      (field_expression "." (identifier) @font-lock-variable-name-face))
+     ;; open tuple assignments (comma separated variables without parentheses)
+     (assignment
+      :anchor
+      (open_tuple (identifier) @font-lock-variable-name-face))
      (assignment
       :anchor
       (open_tuple
-       (field_expression
-        value: (identifier) "." (identifier) @font-lock-variable-name-face)))
-     (local_statement (identifier) @font-lock-variable-name-face)
+       (field_expression "." (identifier) @font-lock-variable-name-face)))
+     ;; closed tuple assignments (comma separated variables with parentheses)
+     (assignment
+      :anchor
+      (tuple_expression (identifier) @font-lock-variable-name-face))
+     (assignment
+      :anchor
+      (tuple_expression
+       (field_expression "." (identifier) @font-lock-variable-name-face)))
+     ;; let blocks
      (let_statement :anchor (identifier) @font-lock-variable-name-face)
      ((let_statement _ @comma :anchor (identifier) @font-lock-variable-name-face)
       (:equal "," @comma))
      (let_binding :anchor (identifier) @font-lock-variable-name-face)
+     ;; local and global statements
+     (local_statement (identifier) @font-lock-variable-name-face)
      (global_statement (identifier) @font-lock-variable-name-face)
+     ;; named (keyword) argument names with assigned values
      (named_argument (identifier) @julia-ts-keyword-argument-face (operator)))
 
    :language 'julia
@@ -177,81 +192,27 @@ Otherwise, the indentation is:
 
    :language 'julia
    :feature 'definition
-   `((function_definition
-      (signature (identifier) @font-lock-function-name-face))
-     (function_definition
-      (signature
-       (call_expression [(identifier) (operator)] @font-lock-function-name-face)))
-     (function_definition
-      (signature
-       (typed_expression
-        (call_expression [(identifier) (operator)] @font-lock-function-name-face))))
-     (function_definition
-      (signature
-       (where_expression
-        (call_expression [(identifier) (operator)] @font-lock-function-name-face))))
-     (function_definition
-      (signature
-       (where_expression
-        (typed_expression
-        (call_expression [(identifier) (operator)] @font-lock-function-name-face)))))
-     (function_definition
-      (signature
-       (call_expression
-        (field_expression
-         value: (identifier) "." (identifier) @font-lock-function-name-face))))
+   `(;; function declaration
      (function_definition
-      (signature
-       (typed_expression
-        (call_expression
-         (field_expression
-          value: (identifier) "." (identifier) @font-lock-function-name-face)))))
-     (macro_definition
-      (signature
-       (call_expression (identifier) @font-lock-function-name-face)))
-     (macro_definition
-      (signature
-       (call_expression
-        (field_expression
-         value: (identifier) "." (identifier) @font-lock-function-name-face))))
-     (abstract_definition
-      (type_head (identifier) @font-lock-type-face))
-     (abstract_definition
-      (type_head (binary_expression (identifier) @font-lock-type-face)))
-     (primitive_definition
-      (type_head (identifier) @font-lock-type-face))
-     (primitive_definition
-      (type_head (binary_expression (identifier) @font-lock-type-face)))
-     (struct_definition
-      (type_head (identifier) @font-lock-type-face))
-     (struct_definition
-      (type_head (binary_expression (identifier) @font-lock-type-face)))
-     (assignment
-      :anchor
-      (call_expression [(identifier) (operator)] @font-lock-function-name-face))
-     (assignment
-      :anchor
-      (call_expression
-       (parenthesized_expression
-        [(identifier) (operator)] @font-lock-function-name-face)))
-     (assignment
-      :anchor
-      (call_expression
-       (field_expression
-        value: (identifier) "." (identifier) @font-lock-function-name-face)))
-     (assignment
-      :anchor
-      (where_expression
-       (call_expression (identifier) @font-lock-function-name-face)))
-     (assignment
-      :anchor
-      (where_expression
-       (call_expression
-        (field_expression
-         value: (identifier) "." (identifier) @font-lock-function-name-face))))
+      (signature (identifier) @font-lock-function-name-face))
+     ;; function definitions (long and short syntax)
+     (call_expression
+      [(identifier) (operator)] @font-lock-function-name-face
+      (:pred julia-ts--fundef-name-p @font-lock-function-name-face))
+     (call_expression
+      (parenthesized_expression
+       [(identifier) (operator)] @font-lock-function-name-face)
+      (:pred julia-ts--fundef-name-p @font-lock-function-name-face))
+     (call_expression
+      (field_expression "." [(identifier) (operator)] @font-lock-function-name-face)
+      (:pred julia-ts--fundef-name-p @font-lock-function-name-face))
+     ;; binary operator definition as assignment
      (assignment
       :anchor
-      (binary_expression _ (operator) @font-lock-function-name-face)))
+      (binary_expression _ (operator) @font-lock-function-name-face))
+     ;; struct/abstract type/primitive type definitions
+     (type_head (identifier) @font-lock-type-face)
+     (type_head (binary_expression (identifier) @font-lock-type-face)))
 
    :language 'julia
    :feature 'error
@@ -315,6 +276,12 @@ Otherwise, the indentation is:
    :override 'keep
    `((quote_expression) @julia-ts-quoted-symbol-face)
 
+   :language 'julia
+   :feature 'string
+   '(((escape_sequence) @font-lock-escape-face)
+     ((prefixed_string_literal prefix: _ @prefix) @font-lock-regexp-face
+      (:equal "r" @prefix)))
+
    :language 'julia
    :feature 'string
    :override 'keep
@@ -432,6 +399,20 @@ Return nil if there is no name or if NODE is not a defun node."
         (lambda (child)
           (equal (treesit-node-type child) type)))))
 
+(defun julia-ts--fundef-name-p (node)
+  "Return non-nil if NODE is the name of a function definition.
+NODE is recognized as such if it has an ancestor that is either a
+`signature' (long syntax) or an `assignment' (short syntax), and
+the first child of this ancestor is also an ancestor."
+  (let ((prev node))
+    (treesit-parent-until
+     node
+     (lambda (ancestor)
+       (prog1
+           (and (member (treesit-node-type ancestor) '("signature" "assignment"))
+                (equal (treesit-node-child ancestor 0) prev))
+         (setq prev ancestor))))))
+
 ;;;###autoload
 (add-to-list 'auto-mode-alist '("\\.jl\\'" . julia-ts-mode))
 

test/Downloads.jl.faceup

@@ -149,7 +149,7 @@ in which case both the inner and outer code and message may be of interest.
     «v:errstr» = err.message
     «v:status» = err.response.status
     «v:message» = err.response.message
-    «v:status_re» = Regex(status == «c:0» ? «s:""» : «s:"\\b»«:julia-ts-string-interpolation-face:$»«D:status»«s:\\b"»)
+    «v:status_re» = Regex(status == «c:0» ? «s:""» : «s:"»«:font-lock-escape-face:\\»«s:b»«:julia-ts-string-interpolation-face:$»«D:status»«:font-lock-escape-face:\\»«s:b"»)
 
     err.code == Curl.CURLE_OK &&
         «k:return» isempty(message) ? «s:"Error status »«:julia-ts-string-interpolation-face:$»«D:status»«s:"» :

test/tree-sitter-corpus.jl

@@ -492,7 +492,6 @@ echo "\033[31mred\033[m"
 # non-standard string literals
 # ==============================
 
-# FIXME: \s shouldn't be an escape_sequence here
 trailing_ws = r"\s+$"
 version = v"1.0"
 K"\\"

test/tree-sitter-corpus.jl.faceup

@@ -227,7 +227,7 @@ Base.«f:foo»(x) = x
     n
 «k:end»
 
-f(n::«t:N», m::«t:M») «k:where» {«t:N» <: «t:Number»} «k:where» {«t:M» <: «t:Integer»} = n^m
+«f:f»(n::«t:N», m::«t:M») «k:where» {«t:N» <: «t:Number»} «k:where» {«t:M» <: «t:Integer»} = n^m
 
 «t:Foo»{«t:T»}(x::«t:T») «k:where» {«t:T»} = x
 
@@ -466,10 +466,10 @@ a -> «v:a» = «c:2», «c:3»
 «x:# ==============================»
 
 «s:""»
-«s:"\""»
+«s:"»«:font-lock-escape-face:\"»«s:"»
 «s:"foo
  bar"»
-«s:"this is a \"string\"."»
+«s:"this is a »«:font-lock-escape-face:\"»«s:string»«:font-lock-escape-face:\"»«s:."»
 «s:"""this is also a "string"."""»
 «v:band» = «s:"Interpol"»
 «s:"»«:julia-ts-string-interpolation-face:$»«D:band»«s: is a cool band"»
@@ -483,19 +483,18 @@ a -> «v:a» = «c:2», «c:3»
 «s:`pwd`»
 «s:m`pwd`»
 «s:`cd »«:julia-ts-string-interpolation-face:$»«D:dir»«s:`»
-«s:`echo \`cmd\``»
+«s:`echo »«:font-lock-escape-face:\`»«s:cmd»«:font-lock-escape-face:\`»«s:`»
 «s:```
-echo "\033[31mred\033[m"
+echo "»«:font-lock-escape-face:\033»«s:[31mred»«:font-lock-escape-face:\033»«s:[m"
 ```»
 
 «x:# ==============================»
 «x:# non-standard string literals»
 «x:# ==============================»
 
-«x:# FIXME: \s shouldn't be an escape_sequence here»
-«v:trailing_ws» = «s:r"\s+$"»
+«v:trailing_ws» = «:font-lock-regexp-face:r"\s+$"»
 «v:version» = «s:v"1.0"»
-«s:K"\\"»
+«s:K"»«:font-lock-escape-face:\\»«s:"»
 
 «x:# ==============================»
 «x:# comments»