Refine the helper function fo building Rust dep

README.md

@@ -88,13 +88,7 @@ Vim-clap is a modern generic interactive finder and dispatcher, based on the new
 
 #### `Rust`
 
-If you have installed Rust on your system, specifically, `cargo` executable exists, you can build the extra tools for a performant and nicer vim-clap using one single command `:call clap#helper#build_all()`.
-
-Notes: [Python dynamic module](https://github.com/liuchengxu/vim-clap#python-dynamic-module) needs to be compiled using Rust nightly, ensure you have installed it:
-
-```bash
-$ rustup toolchain install nightly
-```
+If you have installed Rust on your system, specifically, `cargo` executable exists, you can build the extra tools for a performant and nicer vim-clap using this single command `:call clap#helper#build_all()`.
 
 ##### `maple` binary
 
@@ -107,6 +101,8 @@ $ rustup toolchain install nightly
 To install `maple` you can use the helper function and run `:call clap#helper#build_maple()`, or install it manually:
 
   ```bash
+  cd path/to/vim-clap
+
   # Compile the release build
   cargo build --release
 
@@ -116,7 +112,15 @@ To install `maple` you can use the helper function and run `:call clap#helper#bu
 
 ##### Python dynamic module
 
-Use `:call clap#helper#build_rust_ext()` to install the Python dynamic module written in Rust for 10x faster fuzzy filter than the Python one. Refer to the post [Make Vim Python plugin 10x faster using Rust](http://liuchengxu.org/posts/speed-up-vim-python-plugin-using-rust/) for the whole story.
+If you don't have `+python`, you can safely skip this section, it's totally fine, vim-clap can still work very well with only `maple` binary installed. This Python dynamic module is mainly for saving the async job when the data set is small.
+
+[Python dynamic module](https://github.com/liuchengxu/vim-clap#python-dynamic-module) needs to be compiled using Rust nightly, ensure you have installed it if you want to run the helper function successfully:
+
+```bash
+$ rustup toolchain install nightly
+```
+
+Then use `:call clap#helper#build_python_dynamic_module()` to install the Python dynamic module written in Rust for 10x faster fuzzy filter than the Python one. Refer to the post [Make Vim Python plugin 10x faster using Rust](http://liuchengxu.org/posts/speed-up-vim-python-plugin-using-rust/) for the whole story.
 
 ## Installation
 

autoload/clap/helper.vim

@@ -102,35 +102,61 @@ else
   let s:rust_ext_cwd = fnamemodify(g:clap#autoload_dir, ':h').'/pythonx/clap'
 endif
 
-function! clap#helper#build_rust_ext() abort
+function! s:has_rust_nightly(show_warning) abort
+  call system('cargo +nightly --help')
+  if v:shell_error
+    if a:show_warning
+      call clap#helper#echo_warn('Rust nightly is required, try running `rustup toolchain install nightly` in the command line and then rerun this function.')
+    else
+      call clap#helper#echo_info('Rust nightly is required, skip building the Python dynamic module.')
+    endif
+    return v:false
+  endif
+  return v:true
+endfunction
+
+function! clap#helper#build_python_dynamic_module() abort
+  if !has('python3')
+    call clap#helper#echo_info('+python3 is required, skip building the Python dynamic module.')
+    return
+  endif
+
   if executable('cargo')
-    call s:run_term(s:rust_ext_cmd, s:rust_ext_cwd, 'build Rust extension successfully')
+    if !s:has_rust_nightly(v:true)
+      return
+    endif
+    call s:run_term(s:rust_ext_cmd, s:rust_ext_cwd, 'build Python dynamic module successfully')
   else
-    call clap#helper#echo_error('Can not build Rust extension in that cargo is not found.')
+    call clap#helper#echo_error('Can not build Python dynamic module in that cargo is not found.')
   endif
 endfunction
 
 function! clap#helper#build_maple() abort
   if executable('cargo')
     let cmd = 'cargo build --release'
     let cwd = fnamemodify(g:clap#autoload_dir, ':h')
-    call s:run_term(cmd, cwd, 'build maple successfully')
+    call s:run_term(cmd, cwd, 'build maple binary successfully')
   else
-    call clap#helper#echo_error('Can not build maple in that cargo is not found.')
+    call clap#helper#echo_error('Can not build maple binary in that cargo is not found.')
   endif
 endfunction
 
 function! clap#helper#build_all(...) abort
   if executable('cargo')
-    let cwd = fnamemodify(g:clap#autoload_dir, ':h')
-    if has('win32')
-      let cmd = printf('cargo build --release && cd /d %s && %s', s:rust_ext_cwd, s:rust_ext_cmd)
+    " If Rust nightly and +python3 is unavailable, build the maple only.
+    if has('python3') && s:has_rust_nightly(v:false)
+      let cwd = fnamemodify(g:clap#autoload_dir, ':h')
+      if has('win32')
+        let cmd = printf('cargo build --release && cd /d %s && %s', s:rust_ext_cwd, s:rust_ext_cmd)
+      else
+        let cmd = 'make'
+      endif
+      call s:run_term(cmd, cwd, 'build maple binary and Python dynamic module successfully')
     else
-      let cmd = 'make'
+      call clap#helper#build_maple()
     endif
-    call s:run_term(cmd, cwd, 'build maple and Rust extension successfully')
   else
-    call clap#helper#echo_warn('cargo not found, skipped building maple and the Rust extension.')
+    call clap#helper#echo_warn('cargo not found, skipped building maple binary and Python dynamic module.')
   endif
 endfunction