From e5335dc67339d165a1714abd1df66553913f0454 Mon Sep 17 00:00:00 2001
From: Andy Davidoff <andy+github@disruptek.com>
Date: Sun, 5 Apr 2020 22:21:52 -0400
Subject: [PATCH] 0.8.0: adds choosenim to nimph

---
 README.md    | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 choosenim    | 20 ++++++++++++++++
 nimph.nimble |  2 +-
 3 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100755 choosenim

diff --git a/README.md b/README.md
index 85a10a9..e054558 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,7 @@ or: _How I Learned to Stop Worrying and Love the Search Path_
 - wildcard, tilde, and caret semver
 - absolutely zero configuration
 - total interoperability with Nimble
+- full-featured choosenim replacement
 
 ## Opinions
 
@@ -117,6 +118,7 @@ output (and optional repair) of the environment it finds itself in.
 - [Git Subcommand Auto-Integration](https://github.com/disruptek/nimph#git-subcommands)
 - [Nimble Subcommand Auto-Integration](https://github.com/disruptek/nimph#nimble-subcommands)
 - [Tweaking Nimph Behavior Constants](https://github.com/disruptek/nimph#hacking)
+- [Using `choosenim` to Select Nim Toolchains](https://github.com/disruptek/nimph#choosenim)
 - [Nimph Module Documentation](https://github.com/disruptek/nimph#documentation)
 
 ## Demonstration
@@ -621,6 +623,69 @@ projects.
 Compilation flags to adjust output colors/styling/emojis are found in the
 project's `nimph.nim.cfg`.
 
+## Choose Nimph, Choose Nim!
+
+The `choosenim` tool included in Nimph allows you to easily switch a symbolic
+link between adjacent Nim distributions, wherever you may have installed them.
+
+### Installing `choosenim`
+1. Install [jq](from https://stedolan.github.io/jq/) from GitHub or wherever.
+1. Add the `chosen` toolchain to your `$PATH`.
+1. Run `choosenim` against any of your toolchains.
+```
+# after installing jq however you please...
+$ set --export PATH=/directory/for/all-my-nim-installations/chosen:$PATH
+$ ./choosenim 1.0
+Nim Compiler Version 1.0.7 [Linux: amd64]
+Compiled at 2020-04-05
+Copyright (c) 2006-2019 by Andreas Rumpf
+
+git hash: b6924383df63c91f0ad6baf63d0b1aa84f9329b7
+active boot switches: -d:release
+```
+
+### Using `choosenim`
+- To list available toolchains, run `choosenim`.
+```
+$ choosenim
+.
+├── 1.0
+├── 1.2
+├── chosen -> 1.2
+├── devel
+└── stable -> 1.0
+```
+- Switch toolchains by supplying a name or alias.
+```
+$ choosenim 1.2
+Nim Compiler Version 1.2.0 [Linux: amd64]
+Compiled at 2020-04-05
+Copyright (c) 2006-2020 by Andreas Rumpf
+
+git hash: 7e83adff84be5d0c401a213eccb61e321a3fb1ff
+active boot switches: -d:release
+```
+```
+$ choosenim devel
+Nim Compiler Version 1.3.1 [Linux: amd64]
+Compiled at 2020-04-05
+Copyright (c) 2006-2020 by Andreas Rumpf
+
+git hash: b6814be65349d22fd12944c7c3d19fd8eb44683d
+active boot switches: -d:release
+```
+```
+$ choosenim stable
+Nim Compiler Version 1.0.7 [Linux: amd64]
+Compiled at 2020-04-05
+Copyright (c) 2006-2019 by Andreas Rumpf
+
+git hash: b6924383df63c91f0ad6baf63d0b1aa84f9329b7
+```
+
+### Hacking `choosenim`
+It's a 20-line shell script, buddy; go nuts.
+
 ## Documentation
 
 See [the documentation for the nimph module](https://disruptek.github.io/nimph/nimph.html) as generated directly from the source.
diff --git a/choosenim b/choosenim
new file mode 100755
index 0000000..ebfa07b
--- /dev/null
+++ b/choosenim
@@ -0,0 +1,20 @@
+#!/bin/bash
+CHOOSE=`realpath $0`                   # make note of our origin
+NIM=`nim --hint[Conf]:off --dump.format:json dump config | jq -r .prefixdir`/..
+if [ "$NIM" = "null/.." ]; then        # true when the prefixdir is missing
+	NIM=`dirname \`which nim\``/../..    # fallback for 1.0 support; see #127
+fi
+cd "$NIM"
+if [ -n "$*" ]; then                   # a toolchain was requested
+  if [ -d "$*" ]; then                 # the toolchain is available
+    rm -f chosen                       # ffs my ln -sf should remove it
+    ln -sf "$*" chosen                 # select the chosen toolchain
+    if ! [ -f "chosen/bin/$CHOOSE" ]; then
+      cp -p "$CHOOSE" chosen/bin       # install choosenim if necessary
+    fi
+    nim --version                      # emit current toolchain version
+    exit 0                             # successful selection of toolchain
+  fi
+fi
+tree -v -d -L 1 --noreport             # report on available toolchains
+exit 1                                 # signify failure to switch
diff --git a/nimph.nimble b/nimph.nimble
index a577fc2..fbb82f4 100644
--- a/nimph.nimble
+++ b/nimph.nimble
@@ -1,4 +1,4 @@
-version = "0.7.5"
+version = "0.8.0"
 author = "disruptek"
 description = "nim package handler from the future"
 license = "MIT"