add racer completion for rust

rc/extra/racer.kak

@@ -0,0 +1,62 @@
+decl -hidden str racer_tmp_dir
+decl -hidden completions racer_completions
+
+def racer-complete -docstring "Complete the current selection with racer" %{
+    %sh{
+        dir=$(mktemp -d -t kak-racer.XXXXXXXX)
+        printf %s\\n "set buffer racer_tmp_dir ${dir}"
+        printf %s\\n "eval -no-hooks %{ write ${dir}/buf }"
+    }
+    %sh{
+        dir=${kak_opt_racer_tmp_dir}
+        (
+            cursor="${kak_cursor_line} $((${kak_cursor_column} - 1))"
+            racer_data=$(racer --interface tab-text complete-with-snippet ${cursor} ${kak_buffile} ${dir}/buf)
+            compl=$(printf %s\\n "${racer_data}" | awk '
+                BEGIN { FS = "\t"; ORS = ":" }
+                /^PREFIX/ {
+                    column = ENVIRON["kak_cursor_column"] + $2 - $3
+                    print ENVIRON["kak_cursor_line"] "." column "\\@" ENVIRON["kak_timestamp"]
+                }
+                /^MATCH/ {
+                    word = $2
+                    type = $7
+                    desc = substr($9, 2, length($9) - 2)
+                    gsub(/\\n/, "\n", desc)
+                    menu = $8
+                    sub(/^pub /, "", menu)
+                    gsub(/\|/, "\\|", menu)
+                    if (type == "Function") {
+                        sub(word, "{default+e}" word "{default+d}", menu)
+                        menu = "{default+d}" menu
+                        word = word "("
+                    } else {
+                        menu = "{default+e}" word "{default+d} " menu
+                    }
+                    candidate = word "|" desc "|" menu
+                    gsub(/:/, "\\:", candidate)
+                    print candidate
+                }'
+            )
+            printf %s\\n "eval -client '${kak_client}' %{
+                set buffer=${kak_bufname} racer_completions %@${compl}@
+            }" | kak -p ${kak_session}
+            rm -r ${dir}
+        ) > /dev/null 2>&1 < /dev/null &
+    }
+}
+
+def racer-enable-autocomplete -docstring "Add racer completion candidates to the completer" %{
+    set window completers "option=racer_completions:%opt{completers}"
+    hook window -group racer-autocomplete InsertIdle .* %{ try %{
+        exec -draft <a-h><a-k>([\w\.]|::).\z<ret>
+        racer-complete
+    } }
+    alias window complete racer-complete
+}
+
+def racer-disable-autocomplete -docstring "Disable racer completion" %{
+    set window completers %sh{ printf %s\\n "'${kak_opt_completers}'" | sed 's/option=racer_completions://g' }
+    rmhooks window racer-autocomplete
+    unalias window complete racer-complete
+}