67 lines
1.3 KiB
Markdown
67 lines
1.3 KiB
Markdown
# [The Universal Calculator](https://git.ewanick.com/bill/universal-calculator)
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Using the GHC REPL and Haskell to teach programming concepts through the guise of mathematics.
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A handy assistant to help you understand and solve maths problems.
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- GHC = [Glasgow Haskell Compiler](https://www.haskell.org/ghc/)
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- REPL = [Read Evaluate Print Loop](https://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop)
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- Haskell = [Lazy, Pure, Functional Programming Language](https://www.haskell.org/)
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## How to use
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```Haskell
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λ> 5 * 5
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25
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λ> 1 + 5
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6
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λ> 10 / 2
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5.0
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λ> 10 `div` 2
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5
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λ> 10 `div` 3
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3
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λ> 10 / 3
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3.3333333333333335
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λ> :t sum
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sum :: (Foldable t, Num a) => t a -> a
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λ> :t sum [1..100]
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sum [1..100] :: (Num a, Enum a) => a
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λ> sum [1..100]
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5050
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λ> f x = 5*x^3 + 4*x + 2
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λ> f 1
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11
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λ> f 10
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5042
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λ> f 100
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5000402
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λ> map f [1..10]
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[11,50,149,338,647,1106,1745,2594,3683,5042]
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λ> putStrLn "Hello, world!"
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Hello, world!
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```
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## How to install
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- Use the DeterminateSystems installer to install Nix with Flakes.
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- <https://github.com/DeterminateSystems/nix-installer>
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- `cd` into the top level of this repo.
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- `nix develop` and let Nix load the flake and set everything up.
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- `ghci` and get computing!
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- To disable performance timings after every input, type `λ> :unset +s` in the REPL
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- See other initial commands being run in the `.ghci` file.
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