lukcal

lukcal

The Haskell-based toolkit for LukCal language.

Setup

• ./app - Defines the executable lukcal
• ./src - Defines the library/backend for lukcal
  • ./src/CLI - Defines the CLI interface and handling
  • ./src/Language - Defines the LukCal language tooling

Development

🚚 stack build - builds the project

💨 stack run -- [Arguments] - executes a freshly built project

Getting help

$ stack run -- --help
The lukcal program

lukcal [COMMAND] ... [OPTIONS]

Common flags:
  -c --checktypes=ITEM
  -i --infertypes=ITEM
  -? --help             Display help message
  -V --version          Print version information

lukcal exec [OPTIONS]

  -e --eval=ITEM        Expression to evaluate

lukcal file [OPTIONS]

  -e --eval=FILE        File to evaluate

Evaluating expressions

Expression evaluation is based on simple evaluation logic, defined in ./src/Language/Evaluator.hs

$ stack run -- exec --eval "+ 1 (+ 1 2)"
"Right (NumberResult 4)"

$ stack run -- exec --eval "+ cup cake"
"Right (TextResult \"cupcake\")"

$ stack run -- exec --eval "+ 1 cake"
"Left \"Unsupported operator: +, for inputs: Right (NumberResult 1), and Right (TextResult \\\"cake\\\")\""

Type inferrence

Type inference is based on simple inference logic, defined in ./src/Language/TypeChecker.hs

$ stack run -- exec --infer "+ 1 (+ 1 2)"
"Just (STypeHint \"Number\")"

$ stack run -- exec --infer "+ cup cake"
"Just (STypeHint \"Text\")"

$ stack run -- exec --infer "+ 1 cake"
"Nothing"

Type checking

Type inference is based on naive checking logic on top of type-annotated trees, defined in ./src/Language/TypeChecker.hs

$ stack run -- exec --check "+ 1 (+ 1 2)"
"Right (Just (STypeHint \"Number\"),\"Inferred type is: Just (STypeHint \\\"Number\\\")\")"

$ stack run -- exec --check "+ cup cake"
"Right (Just (STypeHint \"Text\"),\"Inferred type is: Just (STypeHint \\\"Text\\\")\")"

$ stack run -- exec --check "+ 1 cake"
"Left (Nothing,\"Inferred type is: Nothing, specified: Nothing\")"

$ stack run -- exec --check "~~ Number + 1 (+ 1 2)"
"Right (Just (STypeHint \"Number\"),\"Inferred type is: Just (STypeHint \\\"Number\\\"), specified: Just (STypeHint \\\"Number\\\")\")"

$ stack run -- exec --check "~~ Text + 1 (+ 1 2)"
"Left (Nothing,\"Inferred type is: Just (STypeHint \\\"Number\\\"), specified: Just (STypeHint \\\"Text\\\")\")"

📦 stack install - to make LukCal available globally

After this, all examples in section above can replace stack run -- with lukcal-cli

🧰 lukcal-cli is available locally after installing

$ lukcal-cli exec --eval "+ cup cake"
"Right (TextResult \"cupcake\")"

$ lukcal-cli exec --infer "+ 1 (+ 1 2)"
"Just (STypeHint \"Number\")"

$ lukcal-cli exec --check "~~ Text + 1 cake"
"Left (Nothing,\"Inferred type is: Nothing, specified: Just (STypeHint \\\"Text\\\")\")"