The package optparse-applicative provides a Haskell library for parsing options at the command line. A minimal example, providing only minimal help, is as follows:
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module Main (main) where import Options.Applicative main :: IO (() -> ()) main = execParser (info helper fullDesc) |
On Windows 10, the ‘Usage:’ help text depends on how the executable is called and can include a filename extension. For example, at the Command Prompt, a test executable, opTest.exe, […]
The Gtech Cordless Lawnmower comes with a plastic safety key. If the key is misplaced, the mower will safely not work. A spare key became a 3D printing project. I measured the dimensions of the key using a digital caliper and modelled it in Autodesk’s Fusion 360. I exported the model as an STL file […]
About 47.6 million people were registered as entitled to vote in the United Kingdom’s general election on 12 December 2019 and about 32.1 million did so. I used Haskell to view the outcome with cartograms in which each of the 650 constituencies is represented by a regular hexagon of the same size. Turnout percentage I […]
About 47.6 million people were registered as entitled to vote in the United Kingdom’s general election on 12 December 2019 and about 32.1 million did so. I wanted to use Haskell to view the outcome. Results The House of Commons Library publishes the results of the election as two comma-separated values (CSV) files, the smaller […]
I had a lot of data in a table in an Excel spreadsheet file and I was planning to use Haskell to analyse it. The data would be better structured as a database. Microsoft Office 365 provides Access, a database management system (DBMS). Could Haskell access data in an Access .accdb file? The short answer […]
Autodesk’s Fusion 360 allows the parametric modelling of solids. I used it to create a better pill box, where user parameters defined the box diameter (default 38 mm), box height (3 times the radius, between the hemispherical caps), wall thickness (2 mm), minimum wall thickness (0.8 mm), clearance (between the overlapping parts) (0.25 mm), number […]
A right circular cylinder, about three times its radius in height, capped by hemispheres makes a satisfying pill shape. I bisected the pill perpendicular to its axis of circular symmetry to allow both the hemispheres to be 3D printed convex. The two halves would need to be joined. Pill box 1 On my first attempt, […]
My first toadstool was relatively simple. This second one was more complex, including a representation of the ring around the stem and the volva at the base. The cap was modelled to be smoother than the first, using a geodesic sphere based on a cube. Ultimaker’s guide to designing for printability suggests that the minimum […]
Fused filament fabrication (FFF) cannot 3D print on thin air, although bridging over short gaps is possible. The help of support is required if one layer does not overlap sufficiently the layer immediately below it. A simple toadstool was modelled in Hexagon 2.5.0.5 and sliced in Cura 3.4.1. The cap was modelled as a squashed […]
Way back when I bought my Billy bookcases, IKEA offered an extension that added a low cupboard to the base. The extension is no longer available. Plastic stoppers prevented the cupboard doors from swinging inward. At some point, over the years, I lost a stopper. Its replacement seemed an obvious choice for my first 3D […]