Playing around with writing a grammar with pest

Giving up on ANTLR4 for now, pest looks promising though!

Cargo.lock

@@ -12,7 +12,7 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7fc95d1bdb8e6666b2b217308eeeb09f2d6728d104be3e31916cc74d15420331"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.4",
 ]
 
 [[package]]
@@ -357,7 +357,19 @@ dependencies = [
  "cfg-if 0.1.10",
  "constant_time_eq",
  "crypto-mac",
- "digest",
+ "digest 0.9.0",
+]
+
+[[package]]
+name = "block-buffer"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0940dc441f31689269e10ac70eb1002a3a1d3ad1390e030043662eb7fe4688b"
+dependencies = [
+ "block-padding",
+ "byte-tools",
+ "byteorder",
+ "generic-array 0.12.3",
 ]
 
 [[package]]
@@ -366,7 +378,7 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4152116fd6e9dadb291ae18fc1ec3575ed6d84c29642d97890f4b4a3417297e4"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.4",
 ]
 
 [[package]]
@@ -375,7 +387,16 @@ version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fa136449e765dc7faa244561ccae839c394048667929af599b5d931ebe7b7f10"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.4",
+]
+
+[[package]]
+name = "block-padding"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa79dedbb091f449f1f39e53edf88d5dbe95f895dae6135a8d7b881fb5af73f5"
+dependencies = [
+ "byte-tools",
 ]
 
 [[package]]
@@ -408,6 +429,12 @@ dependencies = [
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "byte-tools"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
+
 [[package]]
 name = "byteorder"
 version = "1.3.4"
@@ -597,7 +624,7 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b584a330336237c1eecd3e94266efb216c56ed91225d634cb2991c5f3fd1aeab"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.4",
  "subtle",
 ]
 
@@ -638,13 +665,22 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4d0e2d24e5ee3b23a01de38eefdcd978907890701f08ffffd4cb457ca4ee8d6"
 
+[[package]]
+name = "digest"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3d0c8c8752312f9713efd397ff63acb9f85585afbf179282e720e7704954dd5"
+dependencies = [
+ "generic-array 0.12.3",
+]
+
 [[package]]
 name = "digest"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3dd60d1080a57a05ab032377049e0591415d2b31afd7028356dbf3cc6dcb066"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.4",
 ]
 
 [[package]]
@@ -717,6 +753,12 @@ version = "2.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f7531096570974c3a9dcf9e4b8e1cede1ec26cf5046219fb3b9d897503b9be59"
 
+[[package]]
+name = "fake-simd"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
+
 [[package]]
 name = "fastrand"
 version = "1.4.0"
@@ -872,6 +914,15 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "generic-array"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c68f0274ae0e023facc3c97b2e00f076be70e254bc851d972503b328db79b2ec"
+dependencies = [
+ "typenum",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.14.4"
@@ -956,7 +1007,7 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fe1149865383e4526a43aee8495f9a325f0b806c63ce6427d06336a590abbbc9"
 dependencies = [
- "digest",
+ "digest 0.9.0",
  "hmac",
 ]
 
@@ -967,7 +1018,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "126888268dcc288495a26bf004b38c5fdbb31682f992c84ceb046a1f0fe38840"
 dependencies = [
  "crypto-mac",
- "digest",
+ "digest 0.9.0",
 ]
 
 [[package]]
@@ -1177,6 +1228,12 @@ dependencies = [
  "cfg-if 0.1.10",
 ]
 
+[[package]]
+name = "maplit"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d"
+
 [[package]]
 name = "matches"
 version = "0.1.8"
@@ -1421,6 +1478,14 @@ dependencies = [
  "tide",
 ]
 
+[[package]]
+name = "otto-parser"
+version = "0.1.0"
+dependencies = [
+ "pest",
+ "pest_derive",
+]
+
 [[package]]
 name = "parking"
 version = "2.0.0"
@@ -1433,6 +1498,49 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
 
+[[package]]
+name = "pest"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10f4872ae94d7b90ae48754df22fd42ad52ce740b8f370b03da4835417403e53"
+dependencies = [
+ "ucd-trie",
+]
+
+[[package]]
+name = "pest_derive"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "833d1ae558dc601e9a60366421196a8d94bc0ac980476d0b67e1d0988d72b2d0"
+dependencies = [
+ "pest",
+ "pest_generator",
+]
+
+[[package]]
+name = "pest_generator"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "99b8db626e31e5b81787b9783425769681b347011cc59471e33ea46d2ea0cf55"
+dependencies = [
+ "pest",
+ "pest_meta",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "pest_meta"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54be6e404f5317079812fc8f9f5279de376d8856929e21c184ecf6bbd692a11d"
+dependencies = [
+ "maplit",
+ "pest",
+ "sha-1",
+]
+
 [[package]]
 name = "pin-project"
 version = "0.4.27"
@@ -1830,6 +1938,18 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "sha-1"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7d94d0bede923b3cea61f3f1ff57ff8cdfd77b400fb8f9998949e0cf04163df"
+dependencies = [
+ "block-buffer 0.7.3",
+ "digest 0.8.1",
+ "fake-simd",
+ "opaque-debug 0.2.3",
+]
+
 [[package]]
 name = "sha1"
 version = "0.6.0"
@@ -1842,10 +1962,10 @@ version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2933378ddfeda7ea26f48c555bdad8bb446bf8a3d17832dc83e380d444cfb8c1"
 dependencies = [
- "block-buffer",
+ "block-buffer 0.9.0",
  "cfg-if 0.1.10",
  "cpuid-bool",
- "digest",
+ "digest 0.9.0",
  "opaque-debug 0.3.0",
 ]
 
@@ -2203,6 +2323,12 @@ version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "373c8a200f9e67a0c95e62a4f52fbf80c23b4381c05a17845531982fa99e6b33"
 
+[[package]]
+name = "ucd-trie"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
+
 [[package]]
 name = "unarchive-step"
 version = "0.1.0"
@@ -2258,7 +2384,7 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8326b2c654932e3e4f9196e69d08fdf7cfd718e1dc6f66b347e6024a0c961402"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.4",
  "subtle",
 ]
 

Cargo.toml

@@ -5,6 +5,8 @@ members = [
 
     "osp",
 
+    "parser",
+
     "services/auctioneer",
     "services/eventbus",
     "services/object-store",

parser/.gitignore

@@ -0,0 +1 @@
+target/

parser/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "otto-parser"
+version = "0.1.0"
+authors = ["R. Tyler Croy <rtyler@brokenco.de>"]
+edition = "2018"
+
+[dependencies]
+pest = "~2.1.3"
+pest_derive = "~2.1.0"

parser/src/lib.rs

@@ -0,0 +1,39 @@
+extern crate pest;
+#[macro_use]
+extern crate pest_derive;
+
+use pest::Parser;
+
+#[derive(Parser)]
+#[grammar = "pipeline.pest"]
+struct Pipeline;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let pipeline = Pipeline::parse(Rule::pipeline,
+            r#"
+            pipeline {
+                stages {
+                    stage {
+                        name = 'Build'
+                        steps {
+                            sh 'ls'
+                            sh 'env'
+                        }
+                    }
+
+                    stage {
+                        name = 'Deploy'
+                        steps {
+                            sh 'make deploy'
+                        }
+                    }
+                }
+            }
+            "#).unwrap().next().unwrap();
+    }
+}

parser/src/pipeline.pest

@@ -0,0 +1,25 @@
+// The pipeline PEG 
+
+pipeline = _{ SOI ~ "pipeline" ~ BLOCK_BEGIN ~ stages+ ~ BLOCK_END ~ EOI }
+
+stages = _{ "stages" ~ BLOCK_BEGIN ~ stage+ ~ BLOCK_END }
+stage = _{ "stage" ~
+        BLOCK_BEGIN ~ 
+        ("name" ~ "=" ~ STR) ~
+        steps ~
+        BLOCK_END }
+
+
+steps = _{ "steps" ~ BLOCK_BEGIN ~ step+ ~ BLOCK_END }
+step = _{ ident ~ STR }
+
+ident = @{ ASCII_ALPHA ~ (ASCII_ALPHANUMERIC | "_")* }
+
+
+BLOCK_BEGIN = _{ "{" }
+BLOCK_END = _{ "}" }
+STR = @{ "'" ~ ( "''" | (!"'" ~ ANY) )* ~ "'" }
+
+
+WHITESPACE = _{ (" " | NEWLINE) }
+COMMENT = _{ "#" }