TypeScript Design Goals

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jonathandturner edited this page Sep 16, 2014 · 4 revisions

Introduction

This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.

We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.

Goals

  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.

Non-goals

  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.

Want to contribute to this Wiki?

Fork it and send a pull request.

TypeScript Language Basics

TypeScript Language Advanced

News

TypeScript Contributors

Building Tools for TypeScript

FAQs

Clone this wiki locally

, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
TypeScript Design Goals
Jump to bottomEditNew page

jonathandturner edited this page Sep 16, 2014
·
4 revisions
Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
Want to contribute to this Wiki?
Fork it and send a pull request.
TypeScript Language Basics
TypeScript Language Advanced
News
TypeScript Contributors
Building Tools for TypeScript
FAQs
Clone this wiki locally

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
TypeScript Design Goals
Jump to bottomEditNew page

jonathandturner edited this page Sep 16, 2014
·
4 revisions
Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
Want to contribute to this Wiki?
Fork it and send a pull request.
TypeScript Language Basics
TypeScript Language Advanced
News
TypeScript Contributors
Building Tools for TypeScript
FAQs
Clone this wiki locally

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
TypeScript Design Goals
Jump to bottomEditNew page

jonathandturner edited this page Sep 16, 2014
·
4 revisions
Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
Want to contribute to this Wiki?
Fork it and send a pull request.
TypeScript Language Basics
TypeScript Language Advanced
News
TypeScript Contributors
Building Tools for TypeScript
FAQs
Clone this wiki locally

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
TypeScript Design Goals
Jump to bottomEditNew page

jonathandturner edited this page Sep 16, 2014
·
4 revisions
Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
Want to contribute to this Wiki?
Fork it and send a pull request.
TypeScript Language Basics
TypeScript Language Advanced
News
TypeScript Contributors
Building Tools for TypeScript
FAQs
Clone this wiki locally

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
TypeScript Design Goals
Jump to bottomEditNew page

jonathandturner edited this page Sep 16, 2014
·
4 revisions
Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
Want to contribute to this Wiki?
Fork it and send a pull request.
TypeScript Language Basics
TypeScript Language Advanced
News
TypeScript Contributors
Building Tools for TypeScript
FAQs
Clone this wiki locally

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
TypeScript Design Goals
Jump to bottomEditNew page

jonathandturner edited this page Sep 16, 2014
·
4 revisions
Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
Want to contribute to this Wiki?
Fork it and send a pull request.
TypeScript Language Basics
TypeScript Language Advanced
News
TypeScript Contributors
Building Tools for TypeScript
FAQs
Clone this wiki locally

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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TypeScript Design Goals
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jonathandturner edited this page Sep 16, 2014
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Introduction
This document serves to outline the general design principles we have based the TypeScript language on. While it is by no means exhaustive, it aims to summarize the rules by which we've made many of the decisions that have shaped the language. Some of these rules are subjective, and at times are at odds with each other; reaching the right balance and making the right exceptions is the essence of how successful programming languages are designed.
We recommend reading Chapter 1 of the TypeScript Language Specification for more background on the overall aims of the TypeScript language itself, and how it intends those goals to be achieved.
Goals
  1. Statically identify constructs that are likely to be errors.
  2. Provide a structuring mechanism for larger pieces of code.
  3. Impose no runtime overhead on emitted programs.
  4. Emit clean, idiomatic, recognizable JavaScript code.
  5. Produce a language that is composable and easy to reason about.
  6. Align with current and future ECMAScript proposals.
  7. Preserve runtime behavior of all JavaScript code.
  8. Avoid adding expression-level syntax.
  9. Use a consistent, fully erasable, structural type system.
  10. Be a cross-platform development tool.
  11. Do not cause substantial breaking changes from TypeScript 1.0.
Non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of JavaScript and the intentions of program authors as a guide for what makes the most sense in the language.
  2. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  3. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  4. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
  5. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.
  6. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  7. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.
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