nimaai

Macro pitfalls

Summary of and excerpts from chapter 9 and 10 of On Lisp. Examples are mainly in Common Lisp.

• [Variable capture] (https://gist.github.com/nimaai/2f98cc421c9a51930e16#variable-capture)
• [Macro argument capture] (https://gist.github.com/nimaai/2f98cc421c9a51930e16#macro-argument-capture)
• [Free symbol capture] (https://gist.github.com/nimaai/2f98cc421c9a51930e16#free-symbol-capture)
• [Multiple evaluation] (https://gist.github.com/nimaai/2f98cc421c9a51930e16#multiple-evaluation)
• [Order of evaluation] (https://gist.github.com/nimaai/2f98cc421c9a51930e16#order-of-evaluation)

nimaai

call plug#begin()
Plug 'nvim-tree/nvim-tree.lua'
Plug 'nvim-tree/nvim-web-devicons'
call plug#end()

nimaai

• export MAJOR_VERSION=...
• export GIT_TAG=...
• export GIT_TAG_SUB="leihs-$GIT_TAG"
• export RC_TAG=...
• git branch v/$MAJOR_VERSION-staging origin/master
• git switch --recurse-submodules v/$MAJOR_VERSION-staging
• git pull origin v/$MAJOR_VERSION-staging
• git fetch --recurse-submodules
• git merge origin/master
• vim config/releases.yml

nimaai

Keybase proof

I hereby claim:

• I am nimaai on github.
• I am nimaai (https://keybase.io/nimaai) on keybase.
• I have a public key ASDICWrD8tv55Dv57AxtvPh7uO-dRzuC9vvs2KNOlVmE8wo

To claim this, I am signing this object:

nimaai

Mistakes:

• p.165 Figure 14.6 should be:

(10-) (aor+ [(first) [[(tuple) a] b]])
a
(11-) (aor+ [(first) [[(tuple) a] b]])
b

• p.166 Figure 14.7

nimaai

• type in something => autocomplete menu appears => hover over some item to have it highlighted => click again in the input field => onClickHandler gets fired, whereas it should not in this case
• when one scrolls inside the "Templates" section in the autocomplete menu => then the whole page scrolls and the menu gets detached from the input field
• style the subsections in such a way that the user sees that he can scroll there
• loading icon either for all or even better for each subsection

nimaai

-- BEST
-- "HashAggregate  (cost=478.98..478.99 rows=1 width=67) (actual time=0.159..0.159 rows=1 loops=1)"

 SELECT DISTINCT media_entries.*
 FROM media_entries
 INNER JOIN meta_data md1 ON (md1.media_entry_id = media_entries.id AND md1.string ILIKE '%Tigernase%')
 INNER JOIN meta_data md2 ON md2.media_entry_id = media_entries.id
 INNER JOIN meta_data_keywords ON meta_data_keywords.meta_datum_id = md2.id
 INNER JOIN keywords ON meta_data_keywords.keyword_id = keywords.id AND keywords.term ILIKE '%greis%'
 WHERE (media_entries.get_metadata_and_previews = TRUE

nimaai

Lisp macros guidelines

Summary of and excerpts from [chapter 8 of "On Lisp"] (http://www.bookshelf.jp/texi/onlisp/onlisp_9.html#SEC61). All examples are in Common Lisp.

###No other option except macro

Macros can do two things that functions can't:

1. they can control (or prevent) the evaluation of their arguments.
2. they are expanded right into the calling context (inline expansion).

nimaai

Keybase proof

I hereby claim:

• I am nimaai on github.
• I am nimaai (https://keybase.io/nimaai) on keybase.
• I have a public key whose fingerprint is 568A 8F52 D3A9 6F67 2660 58B8 ED1B D0FA 67C5 27A3

To claim this, I am signing this object:

nimaai

unless File.exist?('Gemfile')
  File.write('Gemfile', <<-GEMFILE)
    source 'https://rubygems.org'
    gem 'rails', github: 'rails/rails'
    gem 'arel', github: 'rails/arel'
    gem 'sqlite3'
  GEMFILE

  system 'bundle'
end