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JSJS
A Strongly Typed Language for the Web
Ayush Jain · Gaurang Sadekar · Bahul Jain · Prakhar Srivastav
Just another day in the Javascript world
JSJS A Strongly Typed Language for the Web Ayush Jain Gaurang - - PowerPoint PPT Presentation
JSJS A Strongly Typed Language for the Web Ayush Jain Gaurang - - PowerPoint PPT Presentation
JSJS A Strongly Typed Language for the Web Ayush Jain Gaurang Sadekar Bahul Jain Prakhar Srivastav Just another day in the Javascript world Feature JSJS JS Type Safety Type Inference Why JSJS? Immutable
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Why JSJS?
Feature JSJS JS
Type Safety
- Type Inference
- Immutable values
- Immutable Collections
- Programming Style
Functional Imperative Works with Node
- Works in the browser
- How does JSJS compare to
JS?
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A Sneak Peak - Syntax
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A Sneak Peak - Syntax
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Functional Programming
Functions everywhere...
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Closures
Local value for a function - kept alive after function has returned
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Error Handling
Error Reporting Exceptions and Exception Handling
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Immutability
- Immutability makes it easier to reason about code
- The val keyword defines a value. No variables in JSJS.
- Names cannot be redefined in the current scope
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Immutable Collections - Lists & Maps
- Uses Facebook’s Immutable.js library to enforce immutability.
- All library functions written is JSJS.
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Immutable Collections - Lists
List Collection Library
hd, tl, empty?, filter, map, fold_left, rev, iter, range, concat, insert, remove, sort, nth, length All functions return new lists (do not modify the list in place)
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Immutable Collections - Map
Map Collection Library
get, set, has?, length, values, keys, count, merge, del All functions return a new map (do not modify the map in place)
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JSJS Type System
T(_) is a generic type that helps with type
Inference or generic user annotations.
TAny is only used for type inference. TNum, TBool, TUnit, TString are data types. TFun is the function type comprising of args
(list of primitives) and a return type.
TList and TMap are composite List and Map
types
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Type Inference - Our ‘Inspiration’
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Type Inference - JSJS vs OCaml
JSJS OCaml
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Type Inference - JSJS vs OCaml
JSJS OCaml
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Type Inference with user annotations
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Type Errors - JSJS vs OCaml
JSJS OCaml
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Type Errors - JSJS vs OCaml
JSJS OCaml
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Demo
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What next?
➔ Tuples ➔ Option Type ➔ Pattern Matching ➔ Javascript FFI ➔ Line Number Error Reporting
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Thank You So long, and thanks for all the fish.