README.md

Envy compiler

Variable times

Compilation flow

Character stream -> grapheme stream -> Token stream -> Syntax tree -> Client code

Character stream

var secret: str

["v", "a", "r", " ", "s", "e", "c", "r", "e", "t", ":", " ", "s", "t", "r", "i", "n", "g"]

Grapheme stream

A grapheme is the smallest unit in language. A char to your average programming language is a single unicode character code point. The difference is that a grapheme is a single character as understood by humans. For example, an emoji like 💆🏽‍♀ is made of multiple unicode characters but understood as one. This is also true for \r\n for example that is 2 unicode characters that represent a single newline.

var 🔑: str

["v", "a", "r", " ", "🔑", ":", " ", "s", "t", "r", "i", "n", "g"]

Token stream

var something: str

pub var something: int

pub var something: url { description = "wow so useful, thanks!" protocol = "https" }

[
Token { kind: "VarKeyword" }, Token { kind: "Identifier", value: "something" }, Token { kind: "VarAssignmentColon" }, Token { kind: "VarType", value: "str" },
Token { kind: "PubKeyword" }, Token { kind: "VarKeyword" }, Token { kind: "Identifier", value: "something" }, Token { kind: "VarAssignmentColon" }, Token { kind: "VarType", value: "int" },
Token { kind: "VarKeyword" }, Token { kind: "Identifier", value: "something" }, Token { kind: "VarAssignmentColon" }, Token { kind: "VarType", value: "url" }, Token { kind: "BlockOpenCurly" }
Token { kind: "AttributeName", value: "description" }, Token { kind: "AttributeAssignmentEquals" }, Token { kind: "StringLiteral", value: "wow so useful, thanks!" },
Token { kind: "AttributeName", value: "protocol" }, Token { kind: "AttributeAssignmentEquals" }, Token { kind: "StringLiteral", value: "https" },
Token { kind: "BlockCloseCurly" }
]

Syntax tree

var secret: str

var some_url_with_api_key: url

pub var some_public_value: int

var some_url_with_api_key_and_description: url { description = "wow so useful, thanks!" protocol = "https" }

SourceFile {
  declarations: [
    Declaration {
      identifier: Identifier { name: "secret" },
      type: "str",
      attributes: None,
      modifiers: None,
    },

    Declaration {
        identifier: Identifier { name: "some_url_with_api_key" },
        type: "url",
        attributes: None,
        modifiers: None,
    },

    Declaration {
        identifier: Identifier { name: "some_public_value" },
        type: "int",
        attributes: None,
        modifiers: [PublicVar { .. }]
    },

    Declaration {
        identifier: Identifier { name: "some_url_with_api_key_and_description" },
        type: "url",
        modifiers: None,
        attributes:  [
            Attribute {
                name = "description",
                value = "wow so useful, thanks!"
            },
            Attribute {
                name = "protocol",
                value = "https"
            }
          ]
    }
    ]

}

Client code

Envy aims to compile into multiple target languages to make integration easy and to allow envy to be opinionated (and useful) throughout the development lifecycle.

Currently you don't see any references to "providers", here is your first introduction. Still WIP, providers allow developers to specify the data sources of various config values. These could be pulled from a central envy config service, or it could be a third party or external secret management system like AWS Secrets Manager or HasiCorp Vault.

By generating client code, we can also handle the fetching of these values at runtime, which is crucial in particular for private values. A private value provided at any point before the runtime is likely easily recoverable by at least a dev team, which makes it recoverable by bad actors.

We could also generate other declarative formats like JSON, YAML, dotenv, etc.

TypeScript

export const secret = () => "some_string_at_build_time";
export const moduleName = {
  otherSecret: () => "some_other_string_at_jit_time",
};
export const asyncModuleName = {
  otherAsyncSecret: async () =>
    await getProvider("some_provider").getValue("other_async_runtime_secret"),
};

const providers = {
  some_provider: class SomeProvider {
    async getValue(key: string) {
      return "value_from_provider";
    }
  },
};

export const getProvider = async (providerName: string) => {
  return new providers[providerName]();
};

Rust

pub fn secret() -> String {
"some_string_at_build_time".to_string()
}

pub struct ModuleName {
pub fn other_secret() -> String {
"some_other_string_at_build_time".to_string()
}

    pub async fn other_async_secret() -> Result<String> {
        get_provider("some_provider").get_value("other_async_scret").await
    }

}

struct SomeProvider {
async fn get_value(&self, key: &str) -> Result<String> {
Ok("value_from_provider".to_string())
}
}

fn get\*provider(provider_name: &str) -> Result<Box<dyn Provider>, Error> {
match provider_name {
"some_provider" => Ok(Box::new(SomeProvider)),

- => Err(Error::new(format!("Provider {} not found", provider_name)))
  }
  }

Rust blocking

For use in syncronous programs, a blocking/non-async/non-tokio version of envy rust client.

// TBC

Python

import asyncio

def secret():
return "some_string_at_build_time"

class ModuleName:
@staticmethod
def other_secret():
return "some_other_string_at_jit_time"

class SomeProvider:
async def get_value(self, key):
return "value_from_provider"

providers = {
"some_provider": SomeProvider
}

async def get_provider(provider_name):
provider_class = providers.get(provider_name)
if provider_class:
return provider_class()
else:
raise ValueError(f"Provider {provider_name} not found")

class AsyncModuleName:
@staticmethod
async def other_async_secret():
provider = await get_provider('some_provider')
return await provider.get_value('other_async_runtime_secret')

Go

// TBC

C

// TBC

Swift

// TBC

Java

// TBC