DOCS: Add a reference for converters to the docsite and some examples.

Also update the README to point to the Docsite as well.

README.md

@@ -80,4 +80,4 @@ ARGS:
 
 ## Language Reference
 
-https://docs.rs/ucg/
+https://ucg.marzhillstudios.com/reference/

docsite/site/content/how-to/_index.md

@@ -0,0 +1,12 @@
++++
+title = "HowTo Guides"
+weight = 3
+sort_by = "weight"
+in_search_index = true
++++
+A collection of useful HowTo Guides
+----------
+
+Some example use cases for ucg.
+
+* <a href="script">Creating a launch script for a docker container.</a>

docsite/site/content/how-to/script.md

@@ -0,0 +1,82 @@
++++
+title = "Creating a launch script for a docker container"
+weight = 1
+sort_by = "weight"
+in_search_index = true
++++
+Let's say we wanted to use ucg generate a launch script for a local jupyter datascience
+notebook container. This HowTo walks you through creating a ucg file that can generate
+a script to launch the container.
+
+First lets define some docker configuration values that we'll use later.
+
+```
+let image_conf = {
+    port = 8888,
+    hostMount = "~/iJulia/notebooks",
+    mountPoint = "/var/iJulia/notebooks",
+};
+```
+
+Then we can define a helper macro for creating our host and port mappings
+
+```
+// A little helper macro for creating our host and port mappings.
+let map_to_container = macro (host, container) => {
+    result = "@:@" % (host, container)
+};
+
+let publish = map_to_container(docker_conf.port, docker_conf.port);
+let volumes = map_to_container(docker_conf.hostMount, docker_conf.mountPoint);
+```
+
+Now we set up our docker run flags.
+
+```
+let docker_flags = {
+    // d because we want this container to daemonize.
+    d = NULL, // no value for this one.
+    // We provide the container name from the environment.
+    name = env.CONTAINER_NAME,
+    // We use our generated publish and volume mappings from above.
+    publish = publish.result,
+    volume = volumes.result,
+};
+```
+
+Finally we are ready to define our jupyter specific flags.
+
+```
+let jupyter_flags = {
+    notebook-dir = docker_conf.mountPoint
+};
+```
+
+Finally we tie it all together into a script and output it as a bash script using
+the exec converter.
+
+```
+let script = {
+    command = "docker",
+    args = [
+        "run", "--rm", docker_flags,
+        "jupyter/datascience-notebook",
+        "jupyter", "notebook", jupyter_flags,
+    ],
+};
+
+out exec script;
+```
+
+The script tuple above will generate the following bash script:
+
+```sh
+#!/usr/bin/env bash
+# Turn on unofficial Bash-Strict-Mode
+set -euo pipefail
+
+exec docker run --rm -d --name '<from-env>' --publish '8888:8888' --volume '~/iJulia/notebooks:/var/iJulia/notebooks' jupyter/datascience-notebook jupyter notebook --notebook-dir '/var/iJulia/notebooks'
+```
+
+The items in the args should be either strings or tuples. The tuples are turned into
+flags using the builtin flag converter.

docsite/site/content/reference/converters.md

@@ -0,0 +1,145 @@
++++
+title = "UCG Converters"
+weight = 5
+sort_by = "weight"
+in_search_index = true
++++
+UCG has several formats it can convert a value into. Each one has various limits and
+restrictions on the values that can be converted to that format.
+
+JSON and YAML
+----
+
+All UCG values can be converted into JSON or YAML. Integers and Floats are turned into 
+Their equivalent number types. Tuples are turned into dicts. Lists are turned into 
+arrays. Strings are turned into strings.
+
+The NULL or empty type is turned into null in JSON or YAML.
+
+TOML
+----
+
+TOML is very similar to the JSON and YAML formats. TOML has no notion of null though 
+so NULL types result in a compile error when converting to TOML.
+
+Command Line Flags
+----
+
+UCG is able to generate command line flags from ucg values following some translation
+rules for each type.
+
+* Empty values are not emitted.
+* Boolean values are translated to "true" and "false" repsectively.
+* Integers and Floats are rendered as numbers.
+* Tuples are rendered as `--field value` pairs for each field.
+  * Nested tuples concatenate the field names to create the field.
+  * Nested Lists generate a new `--field listitem` pair for each item in the list.
+  * For fields that are just one character in length use a single `-`. Use double
+    dashes for fields of longer than one character.
+
+### Example
+
+```
+let flags = {
+    port = 8080,
+    listen = "0.0.0.0",
+    verbose = NULL,
+    dir = [
+        "some/dir",
+        "some/other/dir",
+    ],
+    log = {
+        debug = true,
+        format = "json",
+    },
+}
+```
+
+Generates the following flags in a file with the `.txt` extension.
+
+```
+-port 8080 --listen '0.0.0.0' --verbose --dir 'some/dir' --dir 'some/other/dir' --log.debug true --log.format 'json'
+```
+
+Environment Variables
+--------
+
+ucg is also able to generate environment variables from ucg values following a few
+translation rules.
+
+* Booleans, Integers, Floats, and Strings are output as is.
+* Lists are not output.
+* Tuples are output as a `FIELD=value` for each field with strings surrounded by double
+  quotes.
+  * Nested Tuples are not output.
+
+```
+let vars = {
+    USER = "me",
+    HOSTNAME = "localhost",
+    TWO = 2,
+    VERBOSE = true,
+};
+```
+
+Generates the following in a file with a `.env` extension.
+
+```sh
+USER='me'
+HOSTNAME='localhost'
+TWO=2
+VERBOSE=true
+```
+
+Exec Script
+-----
+
+ucg has an exec converter that will generate a launch script in bash for applications
+that are configured via command line flags or environment variables. The exec converter
+uses a tuple with some required and optional fields to generate the script with.
+
+The `command` field is the path to the application the script will be launching. It is 
+expected to be a string. There must only be one `command` field in the tuple.
+
+The `args` field is a list of command line arguments. The elements of the list can be 
+strings or tuples. There must only be one `args` field in the tuple.
+
+The `env` field is a tuple representing the environment variables that will be set for 
+the application. there must only be one `env` field in the tuple.
+
+### Example
+
+```
+let common_flags = {
+    log-level = "debug",
+    maxMem = "2048M",
+};
+
+let script = {
+    env = {
+        apikey = "foo-key-and-stuff",
+    },
+    command = "my-app",
+    args = [
+        common_flags,
+        "serve", "--port", "8080",
+    ],
+};
+
+out exec script;
+```
+
+The script tuple above will generate the following bash script:
+
+```sh
+#!/usr/bin/env bash
+# Turn on unofficial Bash-Strict-Mode
+set -euo pipefail
+
+VERBOSE_LOG="true"
+
+exec my-app --log-level debug --maxMem 2048M serve --port 8080
+```
+
+The items in the args should be either strings or tuples. The tuples are turned into
+flags using the builtin flag converter.

docsite/site/content/reference/statements.md

@@ -94,4 +94,6 @@ let myconf = {
 out json myconf;
 ```
 
-ucg will output the myconf tuple as json to a file called api_config.json
+ucg will output the myconf tuple as json to a file called api_config.json
+
+Next: <a href="converters">Converters</a>

examples/test_env.env

@@ -0,0 +1,4 @@
+USER='me'
+HOSTNAME='localhost'
+TWO=2
+VERBOSE=true

examples/test_env.ucg

@@ -0,0 +1,8 @@
+let vars = {
+    USER = "me",
+    HOSTNAME = "localhost",
+    TWO = 2,
+    VERBOSE = true,
+};
+
+out env vars;

examples/test_flags.txt

@@ -0,0 +1 @@
+--port 8080 --listen '0.0.0.0' --verbose --dir 'some/dir' --dir 'some/other/dir' --log.debug true--log.format 'json' 

examples/test_flags.ucg

@@ -0,0 +1,15 @@
+let args = {
+    port = 8080,
+    listen = "0.0.0.0",
+    verbose = NULL,
+    dir = [
+        "some/dir",
+        "some/other/dir",
+    ],
+    log = {
+        debug = true,
+        format = "json",
+    },
+};
+
+out flags args;