Command-Line Manipulator of 𝜑-Calculus Expressions

This is a command-line normalizer, rewriter, and dataizer of 𝜑-calculus expressions.

Install Cabal first and then:

cabal update
cabal install phino
phino --version

Then, you write a simple 𝜑-calculus expression in the hello.phi file:

Φ ↦ ⟦ φ ↦ ⟦ Δ ⤍ 68-65-6C-6C-6F ⟧, t ↦ ξ.k, k ↦ ⟦⟧ ⟧

Then, you dataize it (under development):

$ phino dataize hello.phi
"hello"

You can rewrite this expression (under development) with the help of rules defined in the my-rule.yml YAML file (here, the !b is a capturing group, similar to regular expressions):

name: My custom rule
pattern: Δ ⤍ !b
result: Δ ⤍ 62-79-65

Then, rewrite:

$ phino rewrite --rule=my-rule.yml --phi-input=hello.phi
Φ ↦ ⟦ φ ↦ ⟦ Δ ⤍ 62-79-65 ⟧, t ↦ ξ.k, k ↦ ⟦⟧ ⟧

If you want to use many rules, just use --rule as many times as you need:

phino rewrite --rule=rule1.yaml --rule=rule2.yaml ...

If --phi-input is not provided, the 𝜑-expression is taken from stdin:

$ echo 'Φ ↦ ⟦ φ ↦ ⟦ Δ ⤍ 68-65-6C-6C-6F ⟧ ⟧' | phino rewrite --rule=my-rule.yml
Φ ↦ ⟦ φ ↦ ⟦ Δ ⤍ 62-79-65 ⟧ ⟧

You can also use built-in rules, which are designed to normalize expressions (under development):

$ phino rewrite --normalize --phi-input=hello.phi
Φ ↦ ⟦ φ ↦ ⟦ Δ ⤍ 68-65-6C-6C-6F ⟧, t ↦ ⟦⟧, k ↦ ⟦⟧ ⟧

Also phino supports 𝜑-expressions in ASCII format and with syntax sugar. The rewrite command also allows you to desugar the expression and print it in canonical syntax:

$ echo 'Q -> [[ @ -> QQ.io.stdout("hello") ]]' | phino rewrite --nothing
Φ ↦ ⟦
  φ ↦ Φ.org.eolang.io.stdout(
    α0 ↦ Φ.org.eolang.string(
      α0 ↦ Φ.org.eolang.bytes(
        α0 ↦ ⟦ Δ ⤍ 68-65-6C-6C-6F ⟧
      )
    )
  )
⟧

Rule structure

This is BNF-like yaml rule structure:

Rule:
  name: String?
  pattern: String
  result: String
  when: Condition?

Condition:
  - and: [Condition]  # logical AND
  - or:  [Condition]  # logical OR
  - not: Condition    # logical NOT
  - alpha: Attribute  # check if given attribute is alpha
  - in:               # check if attributes exist in bindings
      - [Attribute]   # list of attributes
      - [Binding]     # list of bindings

Check this to find pre defined normalization rules.

Meta variables

The phino supports meta variables to write 𝜑-expression patterns for capturing attributes, bindings, etc.

This is the list of supported meta variables:

• !a || 𝜏 - attribute
• !e || 𝑒 - any expression
• !B || 𝐵 - list of bindings
• !t - tail after expression, sequence of applications and/or dispatches
• !b - bytes in meta delta binding
• !F - function name in meta lambda binding

Every meta variable may also be used with an integer index, like !B1 or 𝜏0.

Incorrect usage of meta variables in 𝜑-expression patterns leads to parsing errors.

How to Contribute

Fork repository, make changes, then send us a pull request. We will review your changes and apply them to the master branch shortly, provided they don't violate our quality standards. To avoid frustration, before sending us your pull request please make sure all your tests pass:

cabal build all
cabal test

You will need GHC and Cabal ≥3.0 or Stack ≥ 3.0 installed.