1633 lines
62 KiB
EmacsLisp
1633 lines
62 KiB
EmacsLisp
;;; rust-mode.el --- A major-mode for editing Rust source code -*-lexical-binding: t-*-
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;; Version: 1.0.5
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;; Author: Mozilla
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;; Url: https://github.com/rust-lang/rust-mode
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;; Keywords: languages
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;; Package-Requires: ((emacs "25.1"))
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;; This file is distributed under the terms of both the MIT license and the
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;; Apache License (version 2.0).
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;;; Commentary:
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;; This package implements a major-mode for editing Rust source code.
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;;; Code:
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(eval-when-compile (require 'rx))
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(defvar rust-load-optional-libraries t
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"Whether loading `rust-mode' also loads optional libraries.
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This variable might soon be remove again.")
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(when rust-load-optional-libraries
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(require 'rust-cargo)
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(require 'rust-compile)
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(require 'rust-playpen)
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(require 'rust-rustfmt))
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(defvar electric-pair-inhibit-predicate)
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(defvar electric-pair-skip-self)
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(defvar electric-indent-chars)
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(defcustom rust-before-save-hook 'rust-before-save-method
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"Function for formatting before save."
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:type 'function
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:group 'rust-mode)
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(defcustom rust-after-save-hook 'rust-after-save-method
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"Default method to handle rustfmt invocation after save."
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:type 'function
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:group 'rust-mode)
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(defvar rust-prettify-symbols-alist
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'(("&&" . ?∧) ("||" . ?∨)
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("<=" . ?≤) (">=" . ?≥) ("!=" . ?≠)
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("INFINITY" . ?∞) ("->" . ?→) ("=>" . ?⇒))
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"Alist of symbol prettifications used for `prettify-symbols-alist'.")
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;;; Customization
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(defgroup rust-mode nil
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"Support for Rust code."
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:link '(url-link "https://www.rust-lang.org/")
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:group 'languages)
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(defcustom rust-indent-offset 4
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"Indent Rust code by this number of spaces."
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:type 'integer
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:group 'rust-mode
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:safe #'integerp)
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(defcustom rust-indent-method-chain nil
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"Indent Rust method chains, aligned by the `.' operators."
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:type 'boolean
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:group 'rust-mode
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:safe #'booleanp)
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(defcustom rust-indent-where-clause nil
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"Indent lines starting with the `where' keyword following a function or trait.
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When nil, `where' will be aligned with `fn' or `trait'."
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:type 'boolean
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:group 'rust-mode
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:safe #'booleanp)
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(defcustom rust-match-angle-brackets t
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"Whether to enable angle bracket (`<' and `>') matching where appropriate."
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:type 'boolean
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:safe #'booleanp
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:group 'rust-mode)
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(defcustom rust-indent-return-type-to-arguments t
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"Indent a line starting with the `->' (RArrow) following a function, aligning
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to the function arguments. When nil, `->' will be indented one level."
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:type 'boolean
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:group 'rust-mode
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:safe #'booleanp)
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;;; Faces
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(define-obsolete-face-alias 'rust-unsafe-face
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'rust-unsafe "0.6.0")
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(define-obsolete-face-alias 'rust-question-mark-face
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'rust-question-mark "0.6.0")
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(define-obsolete-face-alias 'rust-builtin-formatting-macro-face
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'rust-builtin-formatting-macro "0.6.0")
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(define-obsolete-face-alias 'rust-string-interpolation-face
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'rust-string-interpolation "0.6.0")
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(defface rust-unsafe
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'((t :inherit font-lock-warning-face))
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"Face for the `unsafe' keyword."
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:group 'rust-mode)
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(defface rust-question-mark
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'((t :weight bold :inherit font-lock-builtin-face))
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"Face for the question mark operator."
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:group 'rust-mode)
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(defface rust-ampersand-face
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'((t :inherit default))
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"Face for the ampersand reference mark."
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:group 'rust-mode)
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(defface rust-builtin-formatting-macro
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'((t :inherit font-lock-builtin-face))
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"Face for builtin formatting macros (print! &c.)."
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:group 'rust-mode)
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(defface rust-string-interpolation
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'((t :slant italic :inherit font-lock-string-face))
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"Face for interpolating braces in builtin formatting macro strings."
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:group 'rust-mode)
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;;; Syntax
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(defun rust-re-word (inner) (concat "\\<" inner "\\>"))
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(defun rust-re-grab (inner) (concat "\\(" inner "\\)"))
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(defun rust-re-shy (inner) (concat "\\(?:" inner "\\)"))
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(defconst rust-re-ident "[[:word:][:multibyte:]_][[:word:][:multibyte:]_[:digit:]]*")
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(defconst rust-re-lc-ident "[[:lower:][:multibyte:]_][[:word:][:multibyte:]_[:digit:]]*")
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(defconst rust-re-uc-ident "[[:upper:]][[:word:][:multibyte:]_[:digit:]]*")
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(defvar rust-re-vis
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;; pub | pub ( crate ) | pub ( self ) | pub ( super ) | pub ( in SimplePath )
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(concat
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"pub"
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(rust-re-shy
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(concat
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"[[:space:]]*([[:space:]]*"
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(rust-re-shy
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(concat "crate" "\\|"
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"\\(?:s\\(?:elf\\|uper\\)\\)" "\\|"
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;; in SimplePath
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(rust-re-shy
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(concat
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"in[[:space:]]+"
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rust-re-ident
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(rust-re-shy (concat "::" rust-re-ident)) "*"))))
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"[[:space:]]*)"))
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"?"))
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(defconst rust-re-unsafe "unsafe")
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(defconst rust-re-extern "extern")
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(defconst rust-re-async-or-const "async\\|const")
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(defconst rust-re-generic
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(concat "<[[:space:]]*'" rust-re-ident "[[:space:]]*>"))
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(defconst rust-re-union
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(rx-to-string
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`(seq
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(or space line-start)
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(group symbol-start "union" symbol-end)
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(+ space) (regexp ,rust-re-ident))))
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(defun rust-re-item-def (itype)
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(concat (rust-re-word itype)
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(rust-re-shy rust-re-generic) "?"
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"[[:space:]]+" (rust-re-grab rust-re-ident)))
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;; TODO some of this does only make sense for `fn' (unsafe, extern...)
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;; and not other items
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(defun rust-re-item-def-imenu (itype)
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(concat "^[[:space:]]*"
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(rust-re-shy (concat rust-re-vis "[[:space:]]+")) "?"
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(rust-re-shy (concat (rust-re-word "default") "[[:space:]]+")) "?"
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(rust-re-shy (concat (rust-re-shy rust-re-async-or-const) "[[:space:]]+")) "?"
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(rust-re-shy (concat (rust-re-word rust-re-unsafe) "[[:space:]]+")) "?"
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(rust-re-shy (concat (rust-re-word rust-re-extern) "[[:space:]]+"
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(rust-re-shy "\"[^\"]+\"[[:space:]]+") "?")) "?"
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(rust-re-item-def itype)))
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(defvar rust-imenu-generic-expression
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(append (mapcar #'(lambda (x)
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(list (capitalize x) (rust-re-item-def-imenu x) 1))
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'("enum" "struct" "union" "type" "mod" "fn" "trait" "impl"))
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`(("Macro" ,(rust-re-item-def-imenu "macro_rules!") 1)))
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"Value for `imenu-generic-expression' in Rust mode.
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Create a hierarchical index of the item definitions in a Rust file.
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Imenu will show all the enums, structs, etc. in their own subheading.
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Use idomenu (imenu with `ido-mode') for best mileage.")
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(defvar rust-mode-syntax-table
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(let ((table (make-syntax-table)))
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;; Operators
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(dolist (i '(?+ ?- ?* ?/ ?% ?& ?| ?^ ?! ?< ?> ?~ ?@))
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(modify-syntax-entry i "." table))
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;; Strings
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(modify-syntax-entry ?\" "\"" table)
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(modify-syntax-entry ?\\ "\\" table)
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;; Angle brackets. We suppress this with syntactic propertization
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;; when needed
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(modify-syntax-entry ?< "(>" table)
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(modify-syntax-entry ?> ")<" table)
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;; Comments
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(modify-syntax-entry ?/ ". 124b" table)
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(modify-syntax-entry ?* ". 23n" table)
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(modify-syntax-entry ?\n "> b" table)
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(modify-syntax-entry ?\^m "> b" table)
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table)
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"Syntax definitions and helpers.")
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;;; Prettify
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(defun rust--prettify-symbols-compose-p (start end match)
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"Return true iff the symbol MATCH should be composed.
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See `prettify-symbols-compose-predicate'."
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(and (fboundp 'prettify-symbols-default-compose-p)
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(prettify-symbols-default-compose-p start end match)
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;; Make sure || is not a closure with 0 arguments and && is not
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;; a double reference.
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(pcase match
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("||" (not (save-excursion
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(goto-char start)
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(looking-back "\\(?:\\<move\\|[[({:=,;]\\) *"
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(line-beginning-position)))))
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("&&" (char-equal (char-after end) ?\s))
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(_ t))))
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;;; Mode
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(defvar rust-mode-map
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(let ((map (make-sparse-keymap)))
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(define-key map (kbd "C-c C-d") #'rust-dbg-wrap-or-unwrap)
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(when rust-load-optional-libraries
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(define-key map (kbd "C-c C-c C-u") #'rust-compile)
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(define-key map (kbd "C-c C-c C-k") #'rust-check)
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(define-key map (kbd "C-c C-c C-t") #'rust-test)
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(define-key map (kbd "C-c C-c C-r") #'rust-run)
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(define-key map (kbd "C-c C-c C-l") #'rust-run-clippy)
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(define-key map (kbd "C-c C-f") #'rust-format-buffer)
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(define-key map (kbd "C-c C-n") #'rust-goto-format-problem))
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map)
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"Keymap for Rust major mode.")
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;;;###autoload
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(define-derived-mode rust-mode prog-mode "Rust"
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"Major mode for Rust code.
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\\{rust-mode-map}"
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:group 'rust-mode
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:syntax-table rust-mode-syntax-table
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;; Syntax
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(setq-local syntax-propertize-function #'rust-syntax-propertize)
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;; Indentation
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(setq-local indent-line-function 'rust-mode-indent-line)
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;; Fonts
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(setq-local font-lock-defaults
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'(rust-font-lock-keywords
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nil nil nil nil
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(font-lock-syntactic-face-function
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. rust-mode-syntactic-face-function)))
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;; Misc
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(setq-local comment-start "// ")
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(setq-local comment-end "")
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(setq-local open-paren-in-column-0-is-defun-start nil)
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;; Auto indent on }
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(setq-local electric-indent-chars
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(cons ?} (and (boundp 'electric-indent-chars)
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electric-indent-chars)))
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;; Allow paragraph fills for comments
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(setq-local comment-start-skip "\\(?://[/!]*\\|/\\*[*!]?\\)[[:space:]]*")
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(setq-local paragraph-start
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(concat "[[:space:]]*\\(?:"
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comment-start-skip
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"\\|\\*/?[[:space:]]*\\|\\)$"))
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(setq-local paragraph-separate paragraph-start)
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(setq-local normal-auto-fill-function #'rust-do-auto-fill)
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(setq-local fill-paragraph-function #'rust-fill-paragraph)
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(setq-local fill-forward-paragraph-function #'rust-fill-forward-paragraph)
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(setq-local adaptive-fill-function #'rust-find-fill-prefix)
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(setq-local adaptive-fill-first-line-regexp "")
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(setq-local comment-multi-line t)
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(setq-local comment-line-break-function #'rust-comment-indent-new-line)
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(setq-local imenu-generic-expression rust-imenu-generic-expression)
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(setq-local imenu-syntax-alist '((?! . "w"))) ; For macro_rules!
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(setq-local beginning-of-defun-function #'rust-beginning-of-defun)
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(setq-local end-of-defun-function #'rust-end-of-defun)
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(setq-local parse-sexp-lookup-properties t)
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(setq-local electric-pair-inhibit-predicate
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#'rust-electric-pair-inhibit-predicate-wrap)
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(add-function :before-until (local 'electric-pair-skip-self)
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#'rust-electric-pair-skip-self)
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;; Configure prettify
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(setq prettify-symbols-alist rust-prettify-symbols-alist)
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(setq prettify-symbols-compose-predicate #'rust--prettify-symbols-compose-p)
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(add-hook 'before-save-hook rust-before-save-hook nil t)
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(add-hook 'after-save-hook rust-after-save-hook nil t))
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;;;###autoload
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(add-to-list 'auto-mode-alist '("\\.rs\\'" . rust-mode))
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(defvar rust-top-item-beg-re
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(concat "\\s-*\\(?:priv\\|pub\\)?\\s-*"
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;; TODO some of this does only make sense for `fn' (unsafe, extern...)
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;; and not other items
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(rust-re-shy (concat (rust-re-shy rust-re-vis) "[[:space:]]+")) "?"
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(rust-re-shy (concat (rust-re-shy rust-re-async-or-const) "[[:space:]]+")) "?"
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(rust-re-shy (concat (rust-re-shy rust-re-unsafe) "[[:space:]]+")) "?"
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(regexp-opt
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'("enum" "struct" "union" "type" "mod" "fn" "static" "impl"
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"extern" "trait" "async"))
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"\\_>")
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"Start of a Rust item.")
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(defconst rust-re-type-or-constructor
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(rx symbol-start
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(group upper (0+ (any word nonascii digit "_")))
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symbol-end))
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(defconst rust-keywords
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'("as" "async" "await"
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"box" "break"
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"const" "continue" "crate"
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"do" "dyn"
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"else" "enum" "extern" "existential"
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"false" "fn" "for"
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"if" "impl" "in"
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"let" "loop"
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"match" "mod" "move" "mut"
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"priv" "pub"
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"ref" "return"
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"self" "static" "struct" "super"
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"true" "trait" "type" "try"
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"use"
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"virtual"
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"where" "while"
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"yield")
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"Font-locking definitions and helpers.")
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(defconst rust-special-types
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'("u8" "i8"
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"u16" "i16"
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"u32" "i32"
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"u64" "i64"
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"u128" "i128"
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"f32" "f64"
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"isize" "usize"
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"bool"
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"str" "char"))
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(defconst rust-number-with-type
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(eval-when-compile
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(concat
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"\\_<\\(?:0[box]?\\|[1-9]\\)[[:digit:]a-fA-F_.]*\\(?:[eE][+-]?[[:digit:]_]\\)?"
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(regexp-opt '("u8" "i8" "u16" "i16" "u32" "i32" "u64" "i64"
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"u128" "i128" "usize" "isize" "f32" "f64")
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t)
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"\\_>"))
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"Regular expression matching a number with a type suffix.")
|
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|
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(defvar rust-builtin-formatting-macros
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'("eprint"
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"eprintln"
|
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"format"
|
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"print"
|
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"println")
|
||
"List of builtin Rust macros for string formatting.
|
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This is used by `rust-font-lock-keywords'.
|
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\(`write!' is handled separately).")
|
||
|
||
(defvar rust-formatting-macro-opening-re
|
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"[[:space:]\n]*[({[][[:space:]\n]*"
|
||
"Regular expression to match the opening delimiter of a Rust formatting macro.")
|
||
|
||
(defvar rust-start-of-string-re
|
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"\\(?:r#*\\)?\""
|
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"Regular expression to match the start of a Rust raw string.")
|
||
|
||
(defun rust-path-font-lock-matcher (re-ident)
|
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"Match occurrences of RE-IDENT followed by a double-colon.
|
||
Examples include to match names like \"foo::\" or \"Foo::\".
|
||
Does not match type annotations of the form \"foo::<\"."
|
||
`(lambda (limit)
|
||
(catch 'rust-path-font-lock-matcher
|
||
(while t
|
||
(let* ((symbol-then-colons (rx-to-string '(seq (group (regexp ,re-ident)) "::")))
|
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(match (re-search-forward symbol-then-colons limit t)))
|
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(cond
|
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;; If we didn't find a match, there are no more occurrences
|
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;; of foo::, so return.
|
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((null match) (throw 'rust-path-font-lock-matcher nil))
|
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;; If this isn't a type annotation foo::<, we've found a
|
||
;; match, so a return it!
|
||
((not (looking-at (rx (0+ space) "<")))
|
||
(throw 'rust-path-font-lock-matcher match))))))))
|
||
|
||
(defvar rust-font-lock-keywords
|
||
(append
|
||
`(
|
||
;; Keywords proper
|
||
(,(regexp-opt rust-keywords 'symbols) . font-lock-keyword-face)
|
||
|
||
;; Contextual keywords
|
||
("\\_<\\(default\\)[[:space:]]+fn\\_>" 1 font-lock-keyword-face)
|
||
(,rust-re-union 1 font-lock-keyword-face)
|
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|
||
;; Special types
|
||
(,(regexp-opt rust-special-types 'symbols) . font-lock-type-face)
|
||
|
||
;; The unsafe keyword
|
||
("\\_<unsafe\\_>" . 'rust-unsafe)
|
||
|
||
;; Attributes like `#[bar(baz)]` or `#![bar(baz)]` or `#[bar = "baz"]`
|
||
(,(rust-re-grab (concat "#\\!?\\[" rust-re-ident "[^]]*\\]"))
|
||
1 font-lock-preprocessor-face keep)
|
||
|
||
;; Builtin formatting macros
|
||
(,(concat (rust-re-grab
|
||
(concat (rust-re-word (regexp-opt rust-builtin-formatting-macros))
|
||
"!"))
|
||
rust-formatting-macro-opening-re
|
||
"\\(?:" rust-start-of-string-re "\\)?")
|
||
(1 'rust-builtin-formatting-macro)
|
||
(rust-string-interpolation-matcher
|
||
(rust-end-of-string)
|
||
nil
|
||
(0 'rust-string-interpolation t nil)))
|
||
|
||
;; write! macro
|
||
(,(concat (rust-re-grab (concat (rust-re-word "write\\(ln\\)?") "!"))
|
||
rust-formatting-macro-opening-re
|
||
"[[:space:]]*[^\"]+,[[:space:]]*"
|
||
rust-start-of-string-re)
|
||
(1 'rust-builtin-formatting-macro)
|
||
(rust-string-interpolation-matcher
|
||
(rust-end-of-string)
|
||
nil
|
||
(0 'rust-string-interpolation t nil)))
|
||
|
||
;; Syntax extension invocations like `foo!`, highlight including the !
|
||
(,(concat (rust-re-grab (concat rust-re-ident "!")) "[({[:space:][]")
|
||
1 font-lock-preprocessor-face)
|
||
|
||
;; Field names like `foo:`, highlight excluding the :
|
||
(,(concat (rust-re-grab rust-re-ident) "[[:space:]]*:[^:]")
|
||
1 font-lock-variable-name-face)
|
||
|
||
;; CamelCase Means Type Or Constructor
|
||
(,rust-re-type-or-constructor 1 font-lock-type-face)
|
||
|
||
;; Type-inferred binding
|
||
(,(concat "\\_<\\(?:let\\s-+ref\\|let\\|ref\\|for\\)\\s-+\\(?:mut\\s-+\\)?"
|
||
(rust-re-grab rust-re-ident)
|
||
"\\_>")
|
||
1 font-lock-variable-name-face)
|
||
|
||
;; Type names like `Foo::`, highlight excluding the ::
|
||
(,(rust-path-font-lock-matcher rust-re-uc-ident) 1 font-lock-type-face)
|
||
|
||
;; Module names like `foo::`, highlight excluding the ::
|
||
(,(rust-path-font-lock-matcher rust-re-lc-ident) 1 font-lock-constant-face)
|
||
|
||
;; Lifetimes like `'foo`
|
||
(,(concat "'" (rust-re-grab rust-re-ident) "[^']") 1 font-lock-variable-name-face)
|
||
|
||
;; Question mark operator
|
||
("\\?" . 'rust-question-mark)
|
||
("\\(&+\\)\\(?:'\\(?:\\<\\|_\\)\\|\\<\\|[[({:*_|]\\)"
|
||
1 'rust-ampersand-face)
|
||
;; Numbers with type suffix
|
||
(,rust-number-with-type 1 font-lock-type-face)
|
||
)
|
||
|
||
;; Ensure we highlight `Foo` in `struct Foo` as a type.
|
||
(mapcar #'(lambda (x)
|
||
(list (rust-re-item-def (car x))
|
||
1 (cdr x)))
|
||
'(("enum" . font-lock-type-face)
|
||
("struct" . font-lock-type-face)
|
||
("union" . font-lock-type-face)
|
||
("type" . font-lock-type-face)
|
||
("mod" . font-lock-constant-face)
|
||
("use" . font-lock-constant-face)
|
||
("fn" . font-lock-function-name-face)))))
|
||
|
||
(defun rust-end-of-string ()
|
||
"Skip to the end of the current string."
|
||
(save-excursion
|
||
(skip-syntax-forward "^\"|")
|
||
(skip-syntax-forward "\"|")
|
||
(point)))
|
||
|
||
(defun rust-looking-back-str (str)
|
||
"Return non-nil if there's a match on the text before point and STR.
|
||
Like `looking-back' but for fixed strings rather than regexps (so
|
||
that it's not so slow)."
|
||
(let ((len (length str)))
|
||
(and (> (point) len)
|
||
(equal str (buffer-substring-no-properties (- (point) len) (point))))))
|
||
|
||
(defun rust-looking-back-symbols (symbols)
|
||
"Return non-nil if the point is after a member of SYMBOLS.
|
||
SYMBOLS is a list of strings that represent the respective
|
||
symbols."
|
||
(save-excursion
|
||
(let* ((pt-orig (point))
|
||
(beg-of-symbol (progn (forward-thing 'symbol -1) (point)))
|
||
(end-of-symbol (progn (forward-thing 'symbol 1) (point))))
|
||
(and
|
||
(= end-of-symbol pt-orig)
|
||
(member (buffer-substring-no-properties beg-of-symbol pt-orig)
|
||
symbols)))))
|
||
|
||
(defun rust-looking-back-ident ()
|
||
"Non-nil if we are looking backwards at a valid rust identifier."
|
||
(let ((beg-of-symbol (save-excursion (forward-thing 'symbol -1) (point))))
|
||
(looking-back rust-re-ident beg-of-symbol)))
|
||
|
||
(defun rust-looking-back-macro ()
|
||
"Non-nil if looking back at an ident followed by a !
|
||
|
||
This is stricter than rust syntax which allows a space between
|
||
the ident and the ! symbol. If this space is allowed, then we
|
||
would also need a keyword check to avoid `if !(condition)` being
|
||
seen as a macro."
|
||
(if (> (- (point) (point-min)) 1)
|
||
(save-excursion
|
||
(backward-char)
|
||
(and (= ?! (char-after))
|
||
(rust-looking-back-ident)))))
|
||
|
||
;;; Syntax definitions and helpers
|
||
|
||
(defun rust-paren-level () (nth 0 (syntax-ppss)))
|
||
(defun rust-in-str () (nth 3 (syntax-ppss)))
|
||
(defun rust-in-str-or-cmnt () (nth 8 (syntax-ppss)))
|
||
(defun rust-rewind-past-str-cmnt () (goto-char (nth 8 (syntax-ppss))))
|
||
|
||
(defun rust-rewind-irrelevant ()
|
||
(let ((continue t))
|
||
(while continue
|
||
(let ((starting (point)))
|
||
(skip-chars-backward "[:space:]\n")
|
||
(when (rust-looking-back-str "*/")
|
||
(backward-char))
|
||
(when (rust-in-str-or-cmnt)
|
||
(rust-rewind-past-str-cmnt))
|
||
;; Rewind until the point no longer moves
|
||
(setq continue (/= starting (point)))))))
|
||
|
||
(defvar-local rust-macro-scopes nil
|
||
"Cache for the scopes calculated by `rust-macro-scope'.
|
||
|
||
This variable can be `let' bound directly or indirectly around
|
||
`rust-macro-scope' as an optimization but should not be otherwise
|
||
set.")
|
||
|
||
(defun rust-macro-scope (start end)
|
||
"Return the scope of macros in the buffer.
|
||
|
||
The return value is a list of (START END) positions in the
|
||
buffer.
|
||
|
||
If set START and END are optimizations which limit the return
|
||
value to scopes which are approximately with this range."
|
||
(save-excursion
|
||
;; need to special case macro_rules which has unique syntax
|
||
(let ((scope nil)
|
||
(start (or start (point-min)))
|
||
(end (or end (point-max))))
|
||
(goto-char start)
|
||
;; if there is a start move back to the previous top level,
|
||
;; as any macros before that must have closed by this time.
|
||
(let ((top (syntax-ppss-toplevel-pos (syntax-ppss))))
|
||
(when top
|
||
(goto-char top)))
|
||
(while
|
||
(and
|
||
;; The movement below may have moved us passed end, in
|
||
;; which case search-forward will error
|
||
(< (point) end)
|
||
(search-forward "!" end t))
|
||
(let ((pt (point)))
|
||
(cond
|
||
;; in a string or comment is boring, move straight on
|
||
((rust-in-str-or-cmnt))
|
||
;; in a normal macro,
|
||
((and (skip-chars-forward " \t\n\r")
|
||
(memq (char-after)
|
||
'(?\[ ?\( ?\{))
|
||
;; Check that we have a macro declaration after.
|
||
(rust-looking-back-macro))
|
||
(let ((start (point)))
|
||
(ignore-errors (forward-list))
|
||
(setq scope (cons (list start (point)) scope))))
|
||
;; macro_rules, why, why, why did you not use macro syntax??
|
||
((save-excursion
|
||
;; yuck -- last test moves point, even if it fails
|
||
(goto-char (- pt 1))
|
||
(skip-chars-backward " \t\n\r")
|
||
(rust-looking-back-str "macro_rules"))
|
||
(save-excursion
|
||
(when (re-search-forward "[[({]" nil t)
|
||
(backward-char)
|
||
(let ((start (point)))
|
||
(ignore-errors (forward-list))
|
||
(setq scope (cons (list start (point)) scope)))))))))
|
||
;; Return 'empty rather than nil, to indicate a buffer with no
|
||
;; macros at all.
|
||
(or scope 'empty))))
|
||
|
||
(defun rust-in-macro (&optional start end)
|
||
"Return non-nil when point is within the scope of a macro.
|
||
|
||
If START and END are set, minimize the buffer analysis to
|
||
approximately this location as an optimization.
|
||
|
||
Alternatively, if `rust-macro-scopes' is a list use the scope
|
||
information in this variable. This last is an optimization and
|
||
the caller is responsible for ensuring that the data in
|
||
`rust-macro-scopes' is up to date."
|
||
(when (> (rust-paren-level) 0)
|
||
(let ((scopes
|
||
(or
|
||
rust-macro-scopes
|
||
(rust-macro-scope start end))))
|
||
;; `rust-macro-scope' can return the symbol `empty' if the
|
||
;; buffer has no macros at all.
|
||
(when (listp scopes)
|
||
(seq-some
|
||
(lambda (sc)
|
||
(and (>= (point) (car sc))
|
||
(< (point) (cadr sc))))
|
||
scopes)))))
|
||
|
||
(defun rust-looking-at-where ()
|
||
"Return T when looking at the \"where\" keyword."
|
||
(and (looking-at-p "\\bwhere\\b")
|
||
(not (rust-in-str-or-cmnt))))
|
||
|
||
(defun rust-rewind-to-where (&optional limit)
|
||
"Rewind the point to the closest occurrence of the \"where\" keyword.
|
||
Return T iff a where-clause was found. Does not rewind past
|
||
LIMIT when passed, otherwise only stops at the beginning of the
|
||
buffer."
|
||
(when (re-search-backward "\\bwhere\\b" limit t)
|
||
(if (rust-in-str-or-cmnt)
|
||
(rust-rewind-to-where limit)
|
||
t)))
|
||
|
||
(defconst rust-re-pre-expression-operators "[-=!%&*/:<>[{(|.^;}]")
|
||
|
||
(defconst rust-re-special-types (regexp-opt rust-special-types 'symbols))
|
||
|
||
(defun rust-align-to-expr-after-brace ()
|
||
(save-excursion
|
||
(forward-char)
|
||
;; We don't want to indent out to the open bracket if the
|
||
;; open bracket ends the line
|
||
(when (not (looking-at "[[:blank:]]*\\(?://.*\\)?$"))
|
||
(when (looking-at "[[:space:]]")
|
||
(forward-word 1)
|
||
(backward-word 1))
|
||
(current-column))))
|
||
|
||
(defun rust-rewind-to-beginning-of-current-level-expr ()
|
||
(let ((current-level (rust-paren-level)))
|
||
(back-to-indentation)
|
||
(when (looking-at "->")
|
||
(rust-rewind-irrelevant)
|
||
(back-to-indentation))
|
||
(while (> (rust-paren-level) current-level)
|
||
(backward-up-list)
|
||
(back-to-indentation))
|
||
;; When we're in the where clause, skip over it. First find out the start
|
||
;; of the function and its paren level.
|
||
(let ((function-start nil) (function-level nil))
|
||
(save-excursion
|
||
(rust-beginning-of-defun)
|
||
(back-to-indentation)
|
||
;; Avoid using multiple-value-bind
|
||
(setq function-start (point)
|
||
function-level (rust-paren-level)))
|
||
;; On a where clause
|
||
(when (or (rust-looking-at-where)
|
||
;; or in one of the following lines, e.g.
|
||
;; where A: Eq
|
||
;; B: Hash <- on this line
|
||
(and (save-excursion
|
||
(rust-rewind-to-where function-start))
|
||
(= current-level function-level)))
|
||
(goto-char function-start)))))
|
||
|
||
(defun rust-align-to-method-chain ()
|
||
(save-excursion
|
||
;; for method-chain alignment to apply, we must be looking at
|
||
;; another method call or field access or something like
|
||
;; that. This avoids rather "eager" jumps in situations like:
|
||
;;
|
||
;; {
|
||
;; something.foo()
|
||
;; <indent>
|
||
;;
|
||
;; Without this check, we would wind up with the cursor under the
|
||
;; `.`. In an older version, I had the inverse of the current
|
||
;; check, where we checked for situations that should NOT indent,
|
||
;; vs checking for the one situation where we SHOULD. It should be
|
||
;; clear that this is more robust, but also I find it mildly less
|
||
;; annoying to have to press tab again to align to a method chain
|
||
;; than to have an over-eager indent in all other cases which must
|
||
;; be undone via tab.
|
||
|
||
(when (looking-at (concat "\s*\." rust-re-ident))
|
||
(forward-line -1)
|
||
(end-of-line)
|
||
;; Keep going up (looking for a line that could contain a method chain)
|
||
;; while we're in a comment or on a blank line. Stop when the paren
|
||
;; level changes.
|
||
(let ((level (rust-paren-level)))
|
||
(while (and (or (rust-in-str-or-cmnt)
|
||
;; Only whitespace (or nothing) from the beginning to
|
||
;; the end of the line.
|
||
(looking-back "^\s*" (point-at-bol)))
|
||
(= (rust-paren-level) level))
|
||
(forward-line -1)
|
||
(end-of-line)))
|
||
|
||
(let
|
||
;; skip-dot-identifier is used to position the point at the
|
||
;; `.` when looking at something like
|
||
;;
|
||
;; foo.bar
|
||
;; ^ ^
|
||
;; | |
|
||
;; | position of point
|
||
;; returned offset
|
||
;;
|
||
((skip-dot-identifier
|
||
(lambda ()
|
||
(when (and (rust-looking-back-ident)
|
||
(save-excursion
|
||
(forward-thing 'symbol -1)
|
||
(= ?. (char-before))))
|
||
(forward-thing 'symbol -1)
|
||
(backward-char)
|
||
(- (current-column) rust-indent-offset)))))
|
||
(cond
|
||
;; foo.bar(...)
|
||
((looking-back "[)?]" (1- (point)))
|
||
(backward-list 1)
|
||
(funcall skip-dot-identifier))
|
||
|
||
;; foo.bar
|
||
(t (funcall skip-dot-identifier)))))))
|
||
|
||
(defun rust-mode-indent-line ()
|
||
(interactive)
|
||
(let ((indent
|
||
(save-excursion
|
||
(back-to-indentation)
|
||
;; Point is now at beginning of current line
|
||
(let* ((level (rust-paren-level))
|
||
(baseline
|
||
;; Our "baseline" is one level out from the
|
||
;; indentation of the expression containing the
|
||
;; innermost enclosing opening bracket. That way
|
||
;; if we are within a block that has a different
|
||
;; indentation than this mode would give it, we
|
||
;; still indent the inside of it correctly relative
|
||
;; to the outside.
|
||
(if (= 0 level)
|
||
0
|
||
(or
|
||
(when rust-indent-method-chain
|
||
(rust-align-to-method-chain))
|
||
(save-excursion
|
||
(rust-rewind-irrelevant)
|
||
(backward-up-list)
|
||
(rust-rewind-to-beginning-of-current-level-expr)
|
||
(+ (current-column) rust-indent-offset))))))
|
||
(cond
|
||
;; Indent inside a non-raw string only if the previous line
|
||
;; ends with a backslash that is inside the same string
|
||
((nth 3 (syntax-ppss))
|
||
(let*
|
||
((string-begin-pos (nth 8 (syntax-ppss)))
|
||
(end-of-prev-line-pos
|
||
(and (not (rust--same-line-p (point) (point-min)))
|
||
(line-end-position 0))))
|
||
(when
|
||
(and
|
||
;; If the string begins with an "r" it's a raw string and
|
||
;; we should not change the indentation
|
||
(/= ?r (char-after string-begin-pos))
|
||
|
||
;; If we're on the first line this will be nil and the
|
||
;; rest does not apply
|
||
end-of-prev-line-pos
|
||
|
||
;; The end of the previous line needs to be inside the
|
||
;; current string...
|
||
(> end-of-prev-line-pos string-begin-pos)
|
||
|
||
;; ...and end with a backslash
|
||
(= ?\\ (char-before end-of-prev-line-pos)))
|
||
|
||
;; Indent to the same level as the previous line, or the
|
||
;; start of the string if the previous line starts the string
|
||
(if (rust--same-line-p end-of-prev-line-pos string-begin-pos)
|
||
;; The previous line is the start of the string.
|
||
;; If the backslash is the only character after the
|
||
;; string beginning, indent to the next indent
|
||
;; level. Otherwise align with the start of the string.
|
||
(if (> (- end-of-prev-line-pos string-begin-pos) 2)
|
||
(save-excursion
|
||
(goto-char (+ 1 string-begin-pos))
|
||
(current-column))
|
||
baseline)
|
||
|
||
;; The previous line is not the start of the string, so
|
||
;; match its indentation.
|
||
(save-excursion
|
||
(goto-char end-of-prev-line-pos)
|
||
(back-to-indentation)
|
||
(current-column))))))
|
||
|
||
;; A function return type is indented to the corresponding
|
||
;; function arguments, if -to-arguments is selected.
|
||
((and rust-indent-return-type-to-arguments
|
||
(looking-at "->"))
|
||
(save-excursion
|
||
(backward-list)
|
||
(or (rust-align-to-expr-after-brace)
|
||
(+ baseline rust-indent-offset))))
|
||
|
||
;; A closing brace is 1 level unindented
|
||
((looking-at "[]})]") (- baseline rust-indent-offset))
|
||
|
||
;; Doc comments in /** style with leading * indent to line up the *s
|
||
((and (nth 4 (syntax-ppss)) (looking-at "*"))
|
||
(+ 1 baseline))
|
||
|
||
;; When the user chose not to indent the start of the where
|
||
;; clause, put it on the baseline.
|
||
((and (not rust-indent-where-clause)
|
||
(rust-looking-at-where))
|
||
baseline)
|
||
|
||
;; If we're in any other token-tree / sexp, then:
|
||
(t
|
||
(or
|
||
;; If we are inside a pair of braces, with something after the
|
||
;; open brace on the same line and ending with a comma, treat
|
||
;; it as fields and align them.
|
||
(when (> level 0)
|
||
(save-excursion
|
||
(rust-rewind-irrelevant)
|
||
(backward-up-list)
|
||
;; Point is now at the beginning of the containing set of braces
|
||
(rust-align-to-expr-after-brace)))
|
||
|
||
;; When where-clauses are spread over multiple lines, clauses
|
||
;; should be aligned on the type parameters. In this case we
|
||
;; take care of the second and following clauses (the ones
|
||
;; that don't start with "where ")
|
||
(save-excursion
|
||
;; Find the start of the function, we'll use this to limit
|
||
;; our search for "where ".
|
||
(let ((function-start nil) (function-level nil))
|
||
(save-excursion
|
||
;; If we're already at the start of a function,
|
||
;; don't go back any farther. We can easily do
|
||
;; this by moving to the end of the line first.
|
||
(end-of-line)
|
||
(rust-beginning-of-defun)
|
||
(back-to-indentation)
|
||
;; Avoid using multiple-value-bind
|
||
(setq function-start (point)
|
||
function-level (rust-paren-level)))
|
||
;; When we're not on a line starting with "where ", but
|
||
;; still on a where-clause line, go to "where "
|
||
(when (and
|
||
(not (rust-looking-at-where))
|
||
;; We're looking at something like "F: ..."
|
||
(looking-at (concat rust-re-ident ":"))
|
||
;; There is a "where " somewhere after the
|
||
;; start of the function.
|
||
(rust-rewind-to-where function-start)
|
||
;; Make sure we're not inside the function
|
||
;; already (e.g. initializing a struct) by
|
||
;; checking we are the same level.
|
||
(= function-level level))
|
||
;; skip over "where"
|
||
(forward-char 5)
|
||
;; Unless "where" is at the end of the line
|
||
(if (eolp)
|
||
;; in this case the type parameters bounds are just
|
||
;; indented once
|
||
(+ baseline rust-indent-offset)
|
||
;; otherwise, skip over whitespace,
|
||
(skip-chars-forward "[:space:]")
|
||
;; get the column of the type parameter and use that
|
||
;; as indentation offset
|
||
(current-column)))))
|
||
|
||
(progn
|
||
(back-to-indentation)
|
||
;; Point is now at the beginning of the current line
|
||
(if (or
|
||
;; If this line begins with "else" or "{", stay on the
|
||
;; baseline as well (we are continuing an expression,
|
||
;; but the "else" or "{" should align with the beginning
|
||
;; of the expression it's in.)
|
||
;; Or, if this line starts a comment, stay on the
|
||
;; baseline as well.
|
||
(looking-at "\\<else\\>\\|{\\|/[/*]")
|
||
|
||
;; If this is the start of a top-level item,
|
||
;; stay on the baseline.
|
||
(looking-at rust-top-item-beg-re)
|
||
|
||
(save-excursion
|
||
(rust-rewind-irrelevant)
|
||
;; Point is now at the end of the previous line
|
||
(or
|
||
;; If we are at the start of the buffer, no
|
||
;; indentation is needed, so stay at baseline...
|
||
(= (point) 1)
|
||
;; ..or if the previous line ends with any of these:
|
||
;; { ? : ( , ; [ }
|
||
;; then we are at the beginning of an
|
||
;; expression, so stay on the baseline...
|
||
(looking-back "[(,:;[{}]\\|[^|]|" (- (point) 2))
|
||
;; or if the previous line is the end of an
|
||
;; attribute, stay at the baseline...
|
||
(progn (rust-rewind-to-beginning-of-current-level-expr)
|
||
(looking-at "#")))))
|
||
baseline
|
||
|
||
;; Otherwise, we are continuing the same expression from
|
||
;; the previous line, so add one additional indent level
|
||
(+ baseline rust-indent-offset))))))))))
|
||
|
||
(when indent
|
||
;; If we're at the beginning of the line (before or at the current
|
||
;; indentation), jump with the indentation change. Otherwise, save the
|
||
;; excursion so that adding the indentations will leave us at the
|
||
;; equivalent position within the line to where we were before.
|
||
(if (<= (current-column) (current-indentation))
|
||
(indent-line-to indent)
|
||
(save-excursion (indent-line-to indent))))))
|
||
|
||
(defun rust--same-line-p (pos1 pos2)
|
||
"Return non-nil if POS1 and POS2 are on the same line."
|
||
(save-excursion (= (progn (goto-char pos1) (line-end-position))
|
||
(progn (goto-char pos2) (line-end-position)))))
|
||
|
||
;;; Font-locking definitions and helpers
|
||
|
||
(defun rust-next-string-interpolation (limit)
|
||
"Search forward from point for next Rust interpolation marker before LIMIT.
|
||
Set point to the end of the occurrence found, and return match beginning
|
||
and end."
|
||
(catch 'match
|
||
(save-match-data
|
||
(save-excursion
|
||
(while (search-forward "{" limit t)
|
||
(if (eql (char-after (point)) ?{)
|
||
(forward-char)
|
||
(let ((start (match-beginning 0)))
|
||
;; According to fmt_macros::Parser::next, an opening brace
|
||
;; must be followed by an optional argument and/or format
|
||
;; specifier, then a closing brace. A single closing brace
|
||
;; without a corresponding unescaped opening brace is an
|
||
;; error. We don't need to do anything special with
|
||
;; arguments, specifiers, or errors, so we only search for
|
||
;; the single closing brace.
|
||
(when (search-forward "}" limit t)
|
||
(throw 'match (list start (point)))))))))))
|
||
|
||
(defun rust-string-interpolation-matcher (limit)
|
||
"Match next Rust interpolation marker before LIMIT and set match data if found.
|
||
Returns nil if not within a Rust string."
|
||
(when (rust-in-str)
|
||
(let ((match (rust-next-string-interpolation limit)))
|
||
(when match
|
||
(set-match-data match)
|
||
(goto-char (cadr match))
|
||
match))))
|
||
|
||
(defun rust-syntax-class-before-point ()
|
||
(when (> (point) 1)
|
||
(syntax-class (syntax-after (1- (point))))))
|
||
|
||
(defun rust-rewind-qualified-ident ()
|
||
(while (rust-looking-back-ident)
|
||
(backward-sexp)
|
||
(when (save-excursion (rust-rewind-irrelevant) (rust-looking-back-str "::"))
|
||
(rust-rewind-irrelevant)
|
||
(backward-char 2)
|
||
(rust-rewind-irrelevant))))
|
||
|
||
(defun rust-rewind-type-param-list ()
|
||
(cond
|
||
((and (rust-looking-back-str ">") (equal 5 (rust-syntax-class-before-point)))
|
||
(backward-sexp)
|
||
(rust-rewind-irrelevant))
|
||
|
||
;; We need to be able to back up past the Fn(args) -> RT form as well. If
|
||
;; we're looking back at this, we want to end up just after "Fn".
|
||
((member (char-before) '(?\] ?\) ))
|
||
(let* ((is-paren (rust-looking-back-str ")"))
|
||
(dest (save-excursion
|
||
(backward-sexp)
|
||
(rust-rewind-irrelevant)
|
||
(or
|
||
(when (rust-looking-back-str "->")
|
||
(backward-char 2)
|
||
(rust-rewind-irrelevant)
|
||
(when (rust-looking-back-str ")")
|
||
(backward-sexp)
|
||
(point)))
|
||
(and is-paren (point))))))
|
||
(when dest
|
||
(goto-char dest))))))
|
||
|
||
(defun rust-rewind-to-decl-name ()
|
||
"Return the point at the beginning of the name in a declaration.
|
||
I.e. if we are before an ident that is part of a declaration that
|
||
can have a where clause, rewind back to just before the name of
|
||
the subject of that where clause and return the new point.
|
||
Otherwise return nil."
|
||
(let* ((ident-pos (point))
|
||
(newpos (save-excursion
|
||
(rust-rewind-irrelevant)
|
||
(rust-rewind-type-param-list)
|
||
(cond
|
||
((rust-looking-back-symbols
|
||
'("fn" "trait" "enum" "struct" "union" "impl" "type"))
|
||
ident-pos)
|
||
|
||
((equal 5 (rust-syntax-class-before-point))
|
||
(backward-sexp)
|
||
(rust-rewind-to-decl-name))
|
||
|
||
((looking-back "[:,'+=]" (1- (point)))
|
||
(backward-char)
|
||
(rust-rewind-to-decl-name))
|
||
|
||
((rust-looking-back-str "->")
|
||
(backward-char 2)
|
||
(rust-rewind-to-decl-name))
|
||
|
||
((rust-looking-back-ident)
|
||
(rust-rewind-qualified-ident)
|
||
(rust-rewind-to-decl-name))))))
|
||
(when newpos (goto-char newpos))
|
||
newpos))
|
||
|
||
(defun rust-is-in-expression-context (token)
|
||
"Return t if what comes right after the point is part of an
|
||
expression (as opposed to starting a type) by looking at what
|
||
comes before. Takes a symbol that roughly indicates what is
|
||
after the point.
|
||
|
||
This function is used as part of `rust-is-lt-char-operator' as
|
||
part of angle bracket matching, and is not intended to be used
|
||
outside of this context."
|
||
(save-excursion
|
||
(let ((postchar (char-after)))
|
||
(rust-rewind-irrelevant)
|
||
;; A type alias or ascription could have a type param list. Skip backwards past it.
|
||
(when (member token '(ambiguous-operator open-brace))
|
||
(rust-rewind-type-param-list))
|
||
(cond
|
||
|
||
;; Certain keywords always introduce expressions
|
||
((rust-looking-back-symbols '("if" "while" "match" "return" "box" "in")) t)
|
||
|
||
;; "as" introduces a type
|
||
((rust-looking-back-symbols '("as")) nil)
|
||
|
||
;; An open angle bracket never introduces expression context WITHIN the angle brackets
|
||
((and (equal token 'open-brace) (equal postchar ?<)) nil)
|
||
|
||
;; An ident! followed by an open brace is a macro invocation. Consider
|
||
;; it to be an expression.
|
||
((and (equal token 'open-brace) (rust-looking-back-macro)) t)
|
||
|
||
;; In a brace context a "]" introduces an expression.
|
||
((and (eq token 'open-brace) (rust-looking-back-str "]")))
|
||
|
||
;; An identifier is right after an ending paren, bracket, angle bracket
|
||
;; or curly brace. It's a type if the last sexp was a type.
|
||
((and (equal token 'ident) (equal 5 (rust-syntax-class-before-point)))
|
||
(backward-sexp)
|
||
(rust-is-in-expression-context 'open-brace))
|
||
|
||
;; If a "for" appears without a ; or { before it, it's part of an
|
||
;; "impl X for y", so the y is a type. Otherwise it's
|
||
;; introducing a loop, so the y is an expression
|
||
((and (equal token 'ident) (rust-looking-back-symbols '("for")))
|
||
(backward-sexp)
|
||
(rust-rewind-irrelevant)
|
||
(looking-back "[{;]" (1- (point))))
|
||
|
||
((rust-looking-back-ident)
|
||
(rust-rewind-qualified-ident)
|
||
(rust-rewind-irrelevant)
|
||
(cond
|
||
((equal token 'open-brace)
|
||
;; We now know we have:
|
||
;; ident <maybe type params> [{([]
|
||
;; where [{([] denotes either a {, ( or [.
|
||
;; This character is bound as postchar.
|
||
(cond
|
||
;; If postchar is a paren or square bracket, then if the
|
||
;; brace is a type if the identifier is one
|
||
((member postchar '(?\( ?\[ )) (rust-is-in-expression-context 'ident))
|
||
|
||
;; If postchar is a curly brace, the brace can only be a type if
|
||
;; ident2 is the name of an enum, struct or trait being declared.
|
||
;; Note that if there is a -> before the ident then the ident would
|
||
;; be a type but the { is not.
|
||
((equal ?{ postchar)
|
||
(not (and (rust-rewind-to-decl-name)
|
||
(progn
|
||
(rust-rewind-irrelevant)
|
||
(rust-looking-back-symbols
|
||
'("enum" "struct" "union" "trait" "type"))))))))
|
||
|
||
((equal token 'ambiguous-operator)
|
||
(cond
|
||
;; An ampersand after an ident has to be an operator rather
|
||
;; than a & at the beginning of a ref type
|
||
((equal postchar ?&) t)
|
||
|
||
;; A : followed by a type then an = introduces an
|
||
;; expression (unless it is part of a where clause of a
|
||
;; "type" declaration)
|
||
((and (equal postchar ?=)
|
||
(looking-back "[^:]:" (- (point) 2))
|
||
(not (save-excursion
|
||
(and (rust-rewind-to-decl-name)
|
||
(progn (rust-rewind-irrelevant)
|
||
(rust-looking-back-symbols '("type"))))))))
|
||
|
||
;; "let ident =" introduces an expression--and so does "const" and "mut"
|
||
((and (equal postchar ?=) (rust-looking-back-symbols '("let" "const" "mut"))) t)
|
||
|
||
;; As a specific special case, see if this is the = in this situation:
|
||
;; enum EnumName<type params> { Ident =
|
||
;; In this case, this is a c-like enum and despite Ident
|
||
;; representing a type, what comes after the = is an expression
|
||
((and
|
||
(> (rust-paren-level) 0)
|
||
(save-excursion
|
||
(backward-up-list)
|
||
(rust-rewind-irrelevant)
|
||
(rust-rewind-type-param-list)
|
||
(and
|
||
(rust-looking-back-ident)
|
||
(progn
|
||
(rust-rewind-qualified-ident)
|
||
(rust-rewind-irrelevant)
|
||
(rust-looking-back-str "enum")))))
|
||
t)
|
||
|
||
;; Otherwise the ambiguous operator is a type if the identifier is a type
|
||
((rust-is-in-expression-context 'ident) t)))
|
||
|
||
((equal token 'colon)
|
||
(cond
|
||
;; If we see a ident: not inside any braces/parens, we're at top level.
|
||
;; There are no allowed expressions after colons there, just types.
|
||
((<= (rust-paren-level) 0) nil)
|
||
|
||
;; We see ident: inside a list
|
||
((looking-back "[{,]" (1- (point)))
|
||
(backward-up-list)
|
||
|
||
;; If a : appears whose surrounding paren/brackets/braces are
|
||
;; anything other than curly braces, it can't be a field
|
||
;; initializer and must be denoting a type.
|
||
(when (looking-at "{")
|
||
(rust-rewind-irrelevant)
|
||
(rust-rewind-type-param-list)
|
||
(when (rust-looking-back-ident)
|
||
;; We have a context that looks like this:
|
||
;; ident2 <maybe type params> { [maybe paren-balanced code ending in comma] ident1:
|
||
;; the point is sitting just after ident2, and we trying to
|
||
;; figure out if the colon introduces an expression or a type.
|
||
;; The answer is that ident1 is a field name, and what comes
|
||
;; after the colon is an expression, if ident2 is an
|
||
;; expression.
|
||
(rust-rewind-qualified-ident)
|
||
(rust-is-in-expression-context 'ident))))
|
||
|
||
;; Otherwise, if the ident: appeared with anything other than , or {
|
||
;; before it, it can't be part of a struct initializer and therefore
|
||
;; must be denoting a type.
|
||
(t nil)))))
|
||
|
||
;; An operator-like character after a string is indeed an operator
|
||
((and (equal token 'ambiguous-operator)
|
||
(member (rust-syntax-class-before-point) '(5 7 15))) t)
|
||
|
||
;; A colon that has something other than an identifier before it is a
|
||
;; type ascription
|
||
((equal token 'colon) nil)
|
||
|
||
;; A :: introduces a type (or module, but not an expression in any case)
|
||
((rust-looking-back-str "::") nil)
|
||
|
||
((rust-looking-back-str ":")
|
||
(backward-char)
|
||
(rust-is-in-expression-context 'colon))
|
||
|
||
;; A -> introduces a type
|
||
((rust-looking-back-str "->") nil)
|
||
|
||
;; If we are up against the beginning of a list, or after a comma inside
|
||
;; of one, back up out of it and check what the list itself is
|
||
((or
|
||
(equal 4 (rust-syntax-class-before-point))
|
||
(rust-looking-back-str ","))
|
||
(condition-case nil
|
||
(progn
|
||
(backward-up-list)
|
||
(rust-is-in-expression-context 'open-brace))
|
||
(scan-error nil)))
|
||
|
||
;; A => introduces an expression
|
||
((rust-looking-back-str "=>") t)
|
||
|
||
;; A == introduces an expression
|
||
((rust-looking-back-str "==") t)
|
||
|
||
;; These operators can introduce expressions or types
|
||
((looking-back "[-+=!?&*]" (1- (point)))
|
||
(backward-char)
|
||
(rust-is-in-expression-context 'ambiguous-operator))
|
||
|
||
;; These operators always introduce expressions. (Note that if this
|
||
;; regexp finds a < it must not be an angle bracket, or it'd
|
||
;; have been caught in the syntax-class check above instead of this.)
|
||
((looking-back rust-re-pre-expression-operators (1- (point))) t)))))
|
||
|
||
(defun rust-is-lt-char-operator ()
|
||
"Return non-nil if the `<' sign just after point is an operator.
|
||
Otherwise, if it is an opening angle bracket, then return nil."
|
||
(let ((case-fold-search nil))
|
||
(save-excursion
|
||
(rust-rewind-irrelevant)
|
||
;; We are now just after the character syntactically before the <.
|
||
(cond
|
||
|
||
;; If we are looking back at a < that is not an angle bracket (but not
|
||
;; two of them) then this is the second < in a bit shift operator
|
||
((and (rust-looking-back-str "<")
|
||
(not (equal 4 (rust-syntax-class-before-point)))
|
||
(not (rust-looking-back-str "<<"))))
|
||
|
||
;; On the other hand, if we are after a closing paren/brace/bracket it
|
||
;; can only be an operator, not an angle bracket. Likewise, if we are
|
||
;; after a string it's an operator. (The string case could actually be
|
||
;; valid in rust for character literals.)
|
||
((member (rust-syntax-class-before-point) '(5 7 15)) t)
|
||
|
||
;; If we are looking back at an operator, we know that we are at
|
||
;; the beginning of an expression, and thus it has to be an angle
|
||
;; bracket (starting a "<Type as Trait>::" construct.)
|
||
((looking-back rust-re-pre-expression-operators (1- (point))) nil)
|
||
|
||
;; If we are looking back at a keyword, it's an angle bracket
|
||
;; unless that keyword is "self", "true" or "false"
|
||
((rust-looking-back-symbols rust-keywords)
|
||
(rust-looking-back-symbols '("self" "true" "false")))
|
||
|
||
((rust-looking-back-str "?")
|
||
(rust-is-in-expression-context 'ambiguous-operator))
|
||
|
||
;; If we're looking back at an identifier, this depends on whether
|
||
;; the identifier is part of an expression or a type
|
||
((rust-looking-back-ident)
|
||
(backward-sexp)
|
||
(or
|
||
;; The special types can't take type param lists, so a < after one is
|
||
;; always an operator
|
||
(looking-at rust-re-special-types)
|
||
|
||
(rust-is-in-expression-context 'ident)))
|
||
|
||
;; Otherwise, assume it's an angle bracket
|
||
))))
|
||
|
||
(defun rust-electric-pair-inhibit-predicate-wrap (char)
|
||
"Prevent \"matching\" with a `>' when CHAR is the less-than operator.
|
||
This wraps the default defined by `electric-pair-inhibit-predicate'."
|
||
(or
|
||
(when (= ?< char)
|
||
(save-excursion
|
||
(backward-char)
|
||
(rust-is-lt-char-operator)))
|
||
(funcall (default-value 'electric-pair-inhibit-predicate) char)))
|
||
|
||
(defun rust-electric-pair-skip-self (char)
|
||
"Skip CHAR instead of inserting a second closing character.
|
||
This is added to the default skips defined by `electric-pair-skip-self'."
|
||
(= ?> char))
|
||
|
||
(defun rust-ordinary-lt-gt-p ()
|
||
"Test whether the `<' or `>' at point is an ordinary operator of some kind.
|
||
|
||
This returns t if the `<' or `>' is an ordinary operator (like
|
||
less-than) or part of one (like `->'); and nil if the character
|
||
should be considered a paired angle bracket."
|
||
(cond
|
||
;; If matching is turned off suppress all of them
|
||
((not rust-match-angle-brackets) t)
|
||
|
||
;; This is a cheap check so we do it early.
|
||
;; Don't treat the > in -> or => as an angle bracket
|
||
((and (= (following-char) ?>) (memq (preceding-char) '(?- ?=))) t)
|
||
|
||
;; We don't take < or > in strings or comments to be angle brackets
|
||
((rust-in-str-or-cmnt) t)
|
||
|
||
;; Inside a macro we don't really know the syntax. Any < or > may be an
|
||
;; angle bracket or it may not. But we know that the other braces have
|
||
;; to balance regardless of the < and >, so if we don't treat any < or >
|
||
;; as angle brackets it won't mess up any paren balancing.
|
||
((rust-in-macro) t)
|
||
|
||
((= (following-char) ?<)
|
||
(rust-is-lt-char-operator))
|
||
|
||
;; Since rust-ordinary-lt-gt-p is called only when either < or > are at the point,
|
||
;; we know that the following char must be > in the clauses below.
|
||
|
||
;; If we are at top level and not in any list, it can't be a closing
|
||
;; angle bracket
|
||
((>= 0 (rust-paren-level)) t)
|
||
|
||
;; Otherwise, treat the > as a closing angle bracket if it would
|
||
;; match an opening one
|
||
((save-excursion
|
||
(backward-up-list)
|
||
(/= (following-char) ?<)))))
|
||
|
||
(defun rust-mode-syntactic-face-function (state)
|
||
"Return face that distinguishes doc and normal comments in given syntax STATE."
|
||
(if (nth 3 state)
|
||
'font-lock-string-face
|
||
(save-excursion
|
||
(goto-char (nth 8 state))
|
||
(if (looking-at "/\\([*][*!][^*!]\\|/[/!][^/!]\\)")
|
||
'font-lock-doc-face
|
||
'font-lock-comment-face))))
|
||
|
||
(eval-and-compile
|
||
(defconst rust--char-literal-rx
|
||
(rx (seq
|
||
(group "'")
|
||
(or
|
||
(seq
|
||
"\\"
|
||
(or
|
||
(: "u{" (** 1 6 xdigit) "}")
|
||
(: "x" (= 2 xdigit))
|
||
(any "'nrt0\"\\")))
|
||
(not (any "'\\")))
|
||
(group "'")))
|
||
"A regular expression matching a character literal."))
|
||
|
||
(defun rust--syntax-propertize-raw-string (str-start end)
|
||
"A helper for rust-syntax-propertize.
|
||
|
||
This will apply the appropriate string syntax to the character
|
||
from the STR-START up to the end of the raw string, or to END,
|
||
whichever comes first."
|
||
(when (save-excursion
|
||
(goto-char str-start)
|
||
(looking-at "r\\(#*\\)\\(\"\\)"))
|
||
;; In a raw string, so try to find the end.
|
||
(let ((hashes (match-string 1)))
|
||
;; Match \ characters at the end of the string to suppress
|
||
;; their normal character-quote syntax.
|
||
(when (re-search-forward (concat "\\(\\\\*\\)\\(\"" hashes "\\)") end t)
|
||
(put-text-property (match-beginning 1) (match-end 1)
|
||
'syntax-table (string-to-syntax "_"))
|
||
(put-text-property (1- (match-end 2)) (match-end 2)
|
||
'syntax-table (string-to-syntax "|"))
|
||
(goto-char (match-end 0))))))
|
||
|
||
;;; Syntax Propertize
|
||
|
||
(defun rust-syntax-propertize (start end)
|
||
"A `syntax-propertize-function' to apply properties from START to END."
|
||
;; Cache all macro scopes as an optimization. See issue #208
|
||
(let ((rust-macro-scopes (rust-macro-scope start end)))
|
||
(goto-char start)
|
||
(let ((str-start (rust-in-str-or-cmnt)))
|
||
(when str-start
|
||
(rust--syntax-propertize-raw-string str-start end)))
|
||
(funcall
|
||
(syntax-propertize-rules
|
||
;; Character literals.
|
||
(rust--char-literal-rx (1 "\"") (2 "\""))
|
||
;; Raw strings.
|
||
("\\(r\\)#*\""
|
||
(0 (ignore
|
||
(goto-char (match-end 0))
|
||
(unless (save-excursion (nth 8 (syntax-ppss (match-beginning 0))))
|
||
(put-text-property (match-beginning 1) (match-end 1)
|
||
'syntax-table (string-to-syntax "|"))
|
||
(rust--syntax-propertize-raw-string (match-beginning 0) end)))))
|
||
("[<>]"
|
||
(0 (ignore
|
||
(when (save-match-data
|
||
(save-excursion
|
||
(goto-char (match-beginning 0))
|
||
(rust-ordinary-lt-gt-p)))
|
||
(put-text-property (match-beginning 0) (match-end 0)
|
||
'syntax-table (string-to-syntax "."))
|
||
(goto-char (match-end 0)))))))
|
||
(point) end)))
|
||
|
||
(defun rust-fill-prefix-for-comment-start (line-start)
|
||
"Determine what to use for `fill-prefix' based on the text at LINE-START."
|
||
(let ((result
|
||
;; Replace /* with same number of spaces
|
||
(replace-regexp-in-string
|
||
"\\(?:/\\*+?\\)[!*]?"
|
||
(lambda (s)
|
||
;; We want the * to line up with the first * of the
|
||
;; comment start
|
||
(let ((offset (if (eq t
|
||
(compare-strings "/*" nil nil
|
||
s
|
||
(- (length s) 2)
|
||
(length s)))
|
||
1 2)))
|
||
(concat (make-string (- (length s) offset)
|
||
?\x20) "*")))
|
||
line-start)))
|
||
;; Make sure we've got at least one space at the end
|
||
(if (not (= (aref result (- (length result) 1)) ?\x20))
|
||
(setq result (concat result " ")))
|
||
result))
|
||
|
||
(defun rust-in-comment-paragraph (body)
|
||
;; We might move the point to fill the next comment, but we don't want it
|
||
;; seeming to jump around on the user
|
||
(save-excursion
|
||
;; If we're outside of a comment, with only whitespace and then a comment
|
||
;; in front, jump to the comment and prepare to fill it.
|
||
(when (not (nth 4 (syntax-ppss)))
|
||
(beginning-of-line)
|
||
(when (looking-at (concat "[[:space:]\n]*" comment-start-skip))
|
||
(goto-char (match-end 0))))
|
||
|
||
;; We need this when we're moving the point around and then checking syntax
|
||
;; while doing paragraph fills, because the cache it uses isn't always
|
||
;; invalidated during this.
|
||
(syntax-ppss-flush-cache 1)
|
||
;; If we're at the beginning of a comment paragraph with nothing but
|
||
;; whitespace til the next line, jump to the next line so that we use the
|
||
;; existing prefix to figure out what the new prefix should be, rather than
|
||
;; inferring it from the comment start.
|
||
(let ((next-bol (line-beginning-position 2)))
|
||
(while (save-excursion
|
||
(end-of-line)
|
||
(syntax-ppss-flush-cache 1)
|
||
(and (nth 4 (syntax-ppss))
|
||
(save-excursion
|
||
(beginning-of-line)
|
||
(looking-at paragraph-start))
|
||
(looking-at "[[:space:]]*$")
|
||
(nth 4 (syntax-ppss next-bol))))
|
||
(goto-char next-bol)))
|
||
|
||
(syntax-ppss-flush-cache 1)
|
||
;; If we're on the last line of a multiline-style comment that started
|
||
;; above, back up one line so we don't mistake the * of the */ that ends
|
||
;; the comment for a prefix.
|
||
(when (save-excursion
|
||
(and (nth 4 (syntax-ppss (line-beginning-position 1)))
|
||
(looking-at "[[:space:]]*\\*/")))
|
||
(goto-char (line-end-position 0)))
|
||
(funcall body)))
|
||
|
||
(defun rust-with-comment-fill-prefix (body)
|
||
(let*
|
||
((line-string (buffer-substring-no-properties
|
||
(line-beginning-position) (line-end-position)))
|
||
(line-comment-start
|
||
(when (nth 4 (syntax-ppss))
|
||
(cond
|
||
;; If we're inside the comment and see a * prefix, use it
|
||
((string-match "^\\([[:space:]]*\\*+[[:space:]]*\\)"
|
||
line-string)
|
||
(match-string 1 line-string))
|
||
;; If we're at the start of a comment, figure out what prefix
|
||
;; to use for the subsequent lines after it
|
||
((string-match (concat "[[:space:]]*" comment-start-skip) line-string)
|
||
(rust-fill-prefix-for-comment-start
|
||
(match-string 0 line-string))))))
|
||
(fill-prefix
|
||
(or line-comment-start
|
||
fill-prefix)))
|
||
(funcall body)))
|
||
|
||
(defun rust-find-fill-prefix ()
|
||
(rust-in-comment-paragraph
|
||
(lambda ()
|
||
(rust-with-comment-fill-prefix
|
||
(lambda ()
|
||
fill-prefix)))))
|
||
|
||
(defun rust-fill-paragraph (&rest args)
|
||
"Special wrapping for `fill-paragraph'.
|
||
This handles multi-line comments with a * prefix on each line."
|
||
(rust-in-comment-paragraph
|
||
(lambda ()
|
||
(rust-with-comment-fill-prefix
|
||
(lambda ()
|
||
(let
|
||
((fill-paragraph-function
|
||
(if (not (eq fill-paragraph-function #'rust-fill-paragraph))
|
||
fill-paragraph-function))
|
||
(fill-paragraph-handle-comment t))
|
||
(apply #'fill-paragraph args)
|
||
t))))))
|
||
|
||
(defun rust-do-auto-fill (&rest args)
|
||
"Special wrapping for `do-auto-fill'.
|
||
This handles multi-line comments with a * prefix on each line."
|
||
(rust-with-comment-fill-prefix
|
||
(lambda ()
|
||
(apply #'do-auto-fill args)
|
||
t)))
|
||
|
||
(defun rust-fill-forward-paragraph (arg)
|
||
;; This is to work around some funny behavior when a paragraph separator is
|
||
;; at the very top of the file and there is a fill prefix.
|
||
(let ((fill-prefix nil)) (forward-paragraph arg)))
|
||
|
||
(defun rust-comment-indent-new-line (&optional arg)
|
||
(rust-with-comment-fill-prefix
|
||
(lambda () (comment-indent-new-line arg))))
|
||
|
||
;;; Defun Motions
|
||
|
||
(defun rust-beginning-of-defun (&optional arg)
|
||
"Move backward to the beginning of the current defun.
|
||
|
||
With ARG, move backward multiple defuns. Negative ARG means
|
||
move forward.
|
||
|
||
This is written mainly to be used as `beginning-of-defun-function' for Rust.
|
||
Don't move to the beginning of the line. `beginning-of-defun',
|
||
which calls this, does that afterwards."
|
||
(interactive "p")
|
||
(let* ((arg (or arg 1))
|
||
(magnitude (abs arg))
|
||
(sign (if (< arg 0) -1 1)))
|
||
;; If moving forward, don't find the defun we might currently be
|
||
;; on.
|
||
(when (< sign 0)
|
||
(end-of-line))
|
||
(catch 'done
|
||
(dotimes (_ magnitude)
|
||
;; Search until we find a match that is not in a string or comment.
|
||
(while (if (re-search-backward (concat "^\\(" rust-top-item-beg-re "\\)")
|
||
nil 'move sign)
|
||
(rust-in-str-or-cmnt)
|
||
;; Did not find it.
|
||
(throw 'done nil)))))
|
||
t))
|
||
|
||
(defun rust-end-of-defun ()
|
||
"Move forward to the next end of defun.
|
||
|
||
With argument, do it that many times.
|
||
Negative argument -N means move back to Nth preceding end of defun.
|
||
|
||
Assume that this is called after `beginning-of-defun'. So point is
|
||
at the beginning of the defun body.
|
||
|
||
This is written mainly to be used as `end-of-defun-function' for Rust."
|
||
(interactive)
|
||
;; Find the opening brace
|
||
(if (re-search-forward "[{]" nil t)
|
||
(progn
|
||
(goto-char (match-beginning 0))
|
||
;; Go to the closing brace
|
||
(condition-case nil
|
||
(forward-sexp)
|
||
(scan-error
|
||
;; The parentheses are unbalanced; instead of being unable
|
||
;; to fontify, just jump to the end of the buffer
|
||
(goto-char (point-max)))))
|
||
;; There is no opening brace, so consider the whole buffer to be one "defun"
|
||
(goto-char (point-max))))
|
||
|
||
;;; _
|
||
|
||
(defun rust-mode-reload ()
|
||
(interactive)
|
||
(unload-feature 'rust-mode)
|
||
(require 'rust-mode)
|
||
(rust-mode))
|
||
|
||
(provide 'rust-mode)
|
||
(require 'rust-utils)
|
||
|
||
;;; rust-mode.el ends here
|