[notes] some code tips

genericizing-codehtml, body {overflow-x: initial !important;}html { font-size: 14px; }
body { margin: 0px; padding: 0px; height: auto; bottom: 0px; top: 0px; left: 0px; right: 0px; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 1rem; line-height: 1.42857143; color: rgb(51, 51, 51); background-color: rgb(255, 255, 255); overflow-x: hidden; }
a:active, a:hover { outline: 0px; }
::selection { background-color: rgb(181, 214, 252); text-shadow: none; background-position: initial initial; background-repeat: initial initial; }
#write { max-width: 854px; margin: 0px auto; height: auto; width: inherit; word-break: normal; word-wrap: break-word; position: relative; white-space: pre-wrap; text-align: justify; padding-bottom: 70px; }
body.typora-export { padding-left: 30px; padding-right: 30px; }
.typora-export #write { margin: 0px auto; }
#write > p:first-child, #write > ul:first-child, #write > pre:first-child, #write > blockquote:first-child, #write > div:first-child { margin-top: 30px; }
img { max-width: 100%; }
input, button, select, textarea { color: inherit; font-family: inherit; font-size: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
::before, ::after, * { box-sizing: border-box; }
#write p, #write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write div, #write pre { width: inherit; }
h1 { font-size: 2rem; }
p, .mathjax-block { display: block; -webkit-margin-before: 1rem; -webkit-margin-after: 1rem; -webkit-margin-start: 0px; -webkit-margin-end: 0px; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: bold; font-style: italic; }
a { cursor: pointer; }
li span { min-width: 10px; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; margin: 4px 0px 0px; }
tr { page-break-inside: avoid; page-break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; page-break-inside: auto; }
table.md-table td { min-width: 80px; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror-code pre { padding: 0px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
.md-fences, pre.md-fences { font-size: 0.9rem; display: block; page-break-inside: avoid; text-align: left; overflow: visible; white-space: pre; position: relative !important; }
.md-fences .CodeMirror.cm-s-default.CodeMirror-wrap { top: -1.6em; margin-bottom: -1.6em; }
.md-fences.mock-cm { white-space: pre-wrap; }
.footnotes { color: rgb(136, 136, 136); font-size: 0.9rem; padding-top: 1em; padding-bottom: 1em; }
.footnotes + .footnotes { margin-top: -1em; }
sub, sup { line-height: inherit; position: inherit; top: inherit; vertical-align: super; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background-color: transparent; text-decoration: none; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 1rem; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; line-height: normal; font-weight: normal; text-align: left; box-sizing: content-box; direction: ltr; background-position: initial initial; background-repeat: initial initial; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li p, li .mathjax-block { margin: 0.5rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; }
@media print {
html, body { height: 100%; }
.typora-export * { -webkit-print-color-adjust: exact; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
#write pre.md-meta-block { font-size: 0.8rem; min-height: 2.86rem; white-space: pre; background-color: rgb(204, 204, 204); display: block; background-position: initial initial; background-repeat: initial initial; }
p > .md-image:only-child { display: inline-block; width: 100%; text-align: center; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.mathjax-block { white-space: pre; padding-bottom: 0.65rem; overflow: hidden; width: 100%; }
p + .mathjax-block { margin-top: -1.143rem; }
.mathjax-block:not(:empty)::after { display: none; }
[contenteditable="true"]:active, [contenteditable="true"]:focus { outline: none; box-shadow: none; }
:focus { outline: none; box-shadow: rgb(79, 172, 249) 0px 0px 2px 3px, rgb(120, 174, 218) 0px 0px 2px inset; }
.task-list { list-style-type: none; }
.task-list-item { position: relative; padding-left: 1em; }
.task-list-item input { position: absolute; top: 0px; left: 0px; }
.math { font-size: 1rem; }
.md-toc { min-height: 3.58rem; position: relative; font-size: 0.9rem; border-top-left-radius: 10px; border-top-right-radius: 10px; border-bottom-right-radius: 10px; border-bottom-left-radius: 10px; }
.md-toc-content { position: relative; margin-left: 0px; }
.md-toc::after, .md-toc-content::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); text-decoration: none; }
.md-toc-inner:hover { text-decoration: underline; }
.md-toc-inner { display: inline-block; cursor: pointer; }
.md-toc-h1 .md-toc-inner { margin-left: 0px; font-weight: bold; }
.md-toc-h2 .md-toc-inner { margin-left: 2em; }
.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
.md-toc-h6 { margin-left: 12em; }
@media screen and (max-width: 48em) {
.md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
.md-toc-h4 .md-toc-inner { margin-left: 5em; }
.md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 { margin-left: 9.5em; }
}
a.md-toc-inner { color: inherit; font-size: inherit; font-style: inherit; font-weight: inherit; text-decoration: inherit; line-height: inherit; }
.footnote-line a:not(.reversefootnote) { color: inherit; }
.md-attr { display: none; }
.md-fn-count::after { content: '.'; }
.md-tag { opacity: 0.5; }
h1 .md-tag, h2 .md-tag, h3 .md-tag, h4 .md-tag, h5 .md-tag, h6 .md-tag { font-weight: initial; opacity: 0.35; }

html { font-size: 16px; }
html, body { background-color: rgb(243, 242, 238); font-family: 'PT Serif'; color: rgb(31, 9, 9); line-height: 1.5em; }
#write { max-width: 36em; }
ol, ul { list-style: none; }
blockquote, q { quotes: none; }
blockquote::before, blockquote::after, q::before, q::after { content: none; }
table { border-collapse: collapse; border-spacing: 0px; }
h1, h2, h3, h4, h5, h6 { font-weight: bold; }
h1 { font-size: 1.875em; line-height: 1.6em; margin-top: 2em; }
h2, h3 { font-size: 1.3125em; line-height: 1.15; margin-top: 2.285714em; margin-bottom: 1.15em; }
h3 { font-weight: normal; }
h4 { font-size: 1.125em; margin-top: 2.67em; }
h5, h6 { font-size: 1em; }
h1 { border-bottom-width: 1px; border-bottom-style: solid; margin-bottom: 1.875em; padding-bottom: 0.8125em; }
a { text-decoration: none; color: rgb(6, 85, 136); }
a:hover, a:active { text-decoration: underline; }
p, blockquote, pre.md-fences, .md-fences { margin-bottom: 1.5em; }
h1, h2, h3, h4, h5, h6 { margin-bottom: 1.5em; }
blockquote { font-style: italic; border-left-width: 5px; border-left-style: solid; margin-left: 2em; padding-left: 1em; }
ul, ol { margin: 0px 0px 1.5em 1.5em; }
ol li { list-style-type: decimal; list-style-position: outside; }
ul li { list-style-type: disc; list-style-position: outside; }
.md-meta, .md-before, .md-after { color: rgb(153, 153, 153); }
table { margin-bottom: 1.5em; font-size: 1em; }
thead th, tfoot th { padding: 0.25em 0.25em 0.25em 0.4em; text-transform: uppercase; }
th { text-align: left; }
td { vertical-align: top; padding: 0.25em 0.25em 0.25em 0.4em; }
code, pre.md-fences { background-color: rgb(218, 218, 218); padding-left: 1ch; padding-right: 1ch; }
pre.md-fences { margin-left: 2em; margin-bottom: 3em; }
pre, code, tt { font-size: 0.875em; line-height: 1.714285em; }
h1 { line-height: 1.3em; font-weight: normal; margin-bottom: 0.5em; }
p + ul, p + ol { margin-top: -1em; }
h3 + ul, h4 + ul, h5 + ul, h6 + ul, h3 + ol, h4 + ol, h5 + ol, h6 + ol { margin-top: 0.5em; }
li > ul, li > ol { margin-top: inherit; }
h2, h3 { margin-bottom: 0.75em; }
hr { border-style: none none solid; border-bottom-width: 1px; }
h1 { border-color: rgb(197, 197, 197); }
blockquote { border-color: rgb(186, 186, 186); color: rgb(101, 101, 101); }
thead.md-table-edit { background-color: transparent; }
thead { background-color: rgb(218, 218, 218); }
tr:nth-child(even) { background-color: rgb(232, 231, 231); background-position: initial initial; background-repeat: initial initial; }
hr { border-color: rgb(197, 197, 197); }
.task-list { padding-left: 1rem; }
.task-list-item { padding-left: 1.5rem; list-style-type: none; }
.task-list-item input::before { content: '√'; display: inline-block; width: 1.25rem; height: 1.5rem; vertical-align: middle; text-align: center; color: rgb(221, 221, 221); background-color: rgb(243, 242, 238); }
.task-list-item input:checked::before, .task-list-item input[checked]::before { color: inherit; }
#write pre.md-meta-block { min-height: 1.875rem; color: rgb(85, 85, 85); border: 0px; background-color: transparent; margin-left: 1em; margin-top: 1em; background-position: initial initial; background-repeat: initial initial; }
.md-image > .md-meta { color: rgb(155, 81, 70); }
.md-expand.md-image > .md-meta { background-color: rgba(255, 255, 255, 0.65098); }
.md-image > .md-meta { font-family: Menlo, 'Ubuntu Mono', Consolas, 'Courier New', 'Microsoft Yahei', 'Hiragino Sans GB', 'WenQuanYi Micro Hei', sans-serif; }
#write > h3.md-focus::before { left: -2.5rem; color: rgb(153, 153, 153); border-color: rgb(153, 153, 153); }
#write > h4.md-focus::before { left: -2.5rem; top: 0.25rem; color: rgb(153, 153, 153); border-color: rgb(153, 153, 153); }
#write > h5.md-focus::before { left: -2.5rem; color: rgb(153, 153, 153); border-color: rgb(153, 153, 153); }
#write > h6.md-focus::before { left: -2.5rem; top: 0.3125rem; color: rgb(153, 153, 153); border-color: rgb(153, 153, 153); }
.md-toc:focus .md-toc-content { margin-top: 19px; }
.md-toc-content:empty::before { color: rgb(6, 85, 136); }
.md-toc-item { color: rgb(6, 85, 136); }
#write div.md-toc-tooltip { background-color: rgb(243, 242, 238); }
#outline-dropmenu { background-color: rgb(243, 242, 238); -webkit-box-shadow: rgba(0, 0, 0, 0.372549) 0px 6px 12px; box-shadow: rgba(0, 0, 0, 0.372549) 0px 6px 12px; }
.pin-outline #outline-dropmenu { background-image: inherit; background-size: inherit; background-attachment: inherit; background-origin: inherit; background-clip: inherit; background-color: inherit; box-shadow: none; border-right-width: 1px; border-right-style: dashed; background-position: inherit inherit; background-repeat: inherit inherit; }
.pin-outline #outline-dropmenu:hover .outline-title-wrapper { border-left-width: 1px; border-left-style: dashed; }
.outline-item:hover { background-color: rgb(218, 218, 218); border-left-width: 18px; border-left-style: solid; border-left-color: rgb(218, 218, 218); border-right-width: 18px; border-right-style: solid; border-right-color: rgb(218, 218, 218); }
.outline-expander::before { content: ''; font-family: FontAwesome; font-size: 14px; top: 1px; }
.outline-expander:hover::before, .outline-item-open > .outline-item > .outline-expander::before { content: ''; }

Prefer functionality over implementationIt’s never too late to refactorWatch out for repeated code across different typesOne protocol does not rule them allDifferentiate type constraints from parameter constraintsConform at the highest possible levelDesign with collections in mind

genericizing-code

原文链接: http://ericasadun.com/2015/07/31/genericizing-code/

Prefer functionality over implementation

 Focus your code on the connections between data creation and data consumption instead of the particulars of specific types.关注于数据创建和数据消费的关系

It’s never too late to refactor

Watch out for repeated code across different types

One protocol does not rule them all

Differentiate type constraints from parameter constraints

Conform at the highest possible level

Design with collections in mind