HELIX: Add Scheme config and :alt implementation

This leverages helix-editor/helix#8675 to
implement a typed command :alt which switches between C++ source and
header files.

home/helix/dot-config/helix/.gitignore

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+helix/*.scm

home/helix/dot-config/helix/helix.scm

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+(require "helix/editor.scm")
+(require "helix/misc.scm")
+(require (prefix-in helix. "helix/commands.scm"))
+(require (prefix-in helix.static. "helix/static.scm"))
+
+(provide open-helix-scm open-init-scm alt)
+
+;;@doc
+;; Open the helix.scm file
+(define (open-helix-scm)
+  (helix.open (helix.static.get-helix-scm-path)))
+
+;;@doc
+;; Opens the init.scm file
+(define (open-init-scm)
+  (helix.open (helix.static.get-init-scm-path)))
+
+(define (editor-get-doc-if-exists doc-id)
+  (if (editor-doc-exists? doc-id) (editor->get-document doc-id) #f))
+
+(define (current-path)
+  (let* ([focus (editor-focus)]
+         [focus-doc-id (editor->doc-id focus)]
+         [document (editor-get-doc-if-exists focus-doc-id)])
+
+    (if document (Document-path document) #f)))
+
+;;@doc
+;; Toggles between C/C++ source and header files
+(define (alt)
+  (send-lsp-command "clangd" "textDocument/switchSourceHeader"
+                    (hash "uri" (string-append "file://" (current-path)))
+                    (lambda (result)
+                             (helix.open (trim-start-matches result "file://")))))

home/helix/dot-config/helix/init.scm

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+