Adds Pest Grammar to Ion Conversion

Adds the `pestion` crate to provide a simple trait `PestToElement` and
implementations over the Pest AST and `&str` syntax definitions to
create Ion `Element` serialized forms.

Resolves #35.

Author: almann

Cargo.toml

@@ -6,4 +6,5 @@ members = [
   "partiql-irgen",
   "partiql-parser",
   "partiql-rewriter",
+  "pestion",
 ]

pestion/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "pestion"
+authors = ["PartiQL Team <[email protected]>"]
+description = "A simple Pest grammar to Ion converter"
+homepage = "https://github.com/partiql/partiql-lang-rust/pestion"
+repository = "https://github.com/partiql/partiql-lang-rust/pestion"
+license = "Apache-2.0"
+readme = "README.md"
+keywords = ["parser", "peg", "pest", "ion", "cli"]
+categories = ["parser-implementations", "command-line-utilities"]
+exclude = [
+  "**/.git/**",
+  "**/.github/**",
+  "**/.travis.yml",
+  "**/.appveyor.yml",
+]
+edition = "2018"
+version = "0.0.0"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+thiserror = "~1.0.25"
+pest = "~2.1.3"
+pest_meta = "~2.1.3"
+ion-rs = "~0.6.0"
+
+[dev-dependencies]
+rstest = "~0.10.0"

pestion/README.md

@@ -0,0 +1,9 @@
+# Pestion
+
+This is a simple tool and library for converting [Pest] grammars to [Ion] data format.
+
+The motivation for this is to make a portable way to introspect [Pest] grammars in other tools
+as a data format versus having to provide bespoke parsers for the Pest syntax in other platforms.
+
+[Pest]: https://pest.rs/
+[Ion]: https://amzn.github.io/ion-docs/