flatlang: example script

example

(flatlang.Program) {
 Stmts: ([]flatlang.Stmt) (len=10 cap=16) {
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Assign,
   Name: (string) (len=2) "db",
   Exprs: ([]flatlang.Expr) (len=1 cap=1) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.StringNode) {
       Val: (string) (len=17) "sqlite://:memory:"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Assign,
   Name: (string) (len=9) "all_posts",
   Exprs: ([]flatlang.Expr) (len=1 cap=1) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=4 cap=4) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "sql"
      },
      (flatlang.IdentNode) {
       Val: (string) (len=2) "db"
      },
      (flatlang.StringNode) {
       Val: (string) (len=47) "select * from posts limit :limit offset :offset"
      },
      (flatlang.StringNode) {
       Val: (string) (len=5) "posts"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Assign,
   Name: (string) (len=9) "find_post",
   Exprs: ([]flatlang.Expr) (len=1 cap=1) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=4 cap=4) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "sql"
      },
      (flatlang.IdentNode) {
       Val: (string) (len=2) "db"
      },
      (flatlang.StringNode) {
       Val: (string) (len=34) "select * from posts where id = :id"
      },
      (flatlang.StringNode) {
       Val: (string) (len=4) "post"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Assign,
   Name: (string) (len=8) "new_post",
   Exprs: ([]flatlang.Expr) (len=1 cap=1) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=4 cap=4) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "sql"
      },
      (flatlang.IdentNode) {
       Val: (string) (len=2) "db"
      },
      (flatlang.StringNode) {
       Val: (string) (len=75) "insert into posts (author, content) values (:author, :content) returning id"
      },
      (flatlang.StringNode) {
       Val: (string) (len=2) "id"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Assign,
   Name: (string) (len=13) "expanded_form",
   Exprs: ([]flatlang.Expr) (len=1 cap=1) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "sql"
      },
      (flatlang.MapNode) {
       Fields: ([]flatlang.Field) (len=3 cap=4) {
        (flatlang.Field) {
         Key: (string) (len=2) "db",
         Val: (flatlang.IdentNode) {
          Val: (string) (len=2) "db"
         }
        },
        (flatlang.Field) {
         Key: (string) (len=5) "query",
         Val: (flatlang.StringNode) {
          Val: (string) (len=47) "select * from posts limit :limit offset :offset"
         }
        },
        (flatlang.Field) {
         Key: (string) (len=3) "set",
         Val: (flatlang.StringNode) {
          Val: (string) (len=5) "posts"
         }
        }
       }
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Assign,
   Name: (string) (len=8) "paginate",
   Exprs: ([]flatlang.Expr) (len=3 cap=4) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=7) "default"
      },
      (flatlang.MapNode) {
       Fields: ([]flatlang.Field) (len=2 cap=2) {
        (flatlang.Field) {
         Key: (string) (len=6) "offset",
         Val: (flatlang.IntNode) {
          Val: (int64) 0
         }
        },
        (flatlang.Field) {
         Key: (string) (len=5) "limit",
         Val: (flatlang.IntNode) {
          Val: (int64) 1024
         }
        }
       }
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=7) "require"
      },
      (flatlang.MapNode) {
       Fields: ([]flatlang.Field) (len=2 cap=2) {
        (flatlang.Field) {
         Key: (string) (len=6) "offset",
         Val: (flatlang.UnaryNode) {
          Type: (flatlang.TokenType) >=,
          Right: (flatlang.IntNode) {
           Val: (int64) 0
          }
         }
        },
        (flatlang.Field) {
         Key: (string) (len=5) "limit",
         Val: (flatlang.BinaryNode) {
          Left: (flatlang.UnaryNode) {
           Type: (flatlang.TokenType) >=,
           Right: (flatlang.IntNode) {
            Val: (int64) 0
           }
          },
          Type: (flatlang.TokenType) &,
          Right: (flatlang.UnaryNode) {
           Type: (flatlang.TokenType) <=,
           Right: (flatlang.IntNode) {
            Val: (int64) 1024
           }
          }
         }
        }
       }
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "set"
      },
      (flatlang.ListNode) {
       Items: ([]flatlang.Node) (len=2 cap=2) {
        (flatlang.StringNode) {
         Val: (string) (len=5) "limit"
        },
        (flatlang.StringNode) {
         Val: (string) (len=6) "offset"
        }
       }
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Call,
   Name: (string) "",
   Exprs: ([]flatlang.Expr) (len=4 cap=4) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "get"
      },
      (flatlang.StringNode) {
       Val: (string) (len=6) "/posts"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=8) "paginate"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=9) "find_post"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=6) "encode"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Call,
   Name: (string) "",
   Exprs: ([]flatlang.Expr) (len=3 cap=4) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "get"
      },
      (flatlang.StringNode) {
       Val: (string) (len=10) "/posts/:id"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=9) "find_post"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=6) "encode"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Call,
   Name: (string) "",
   Exprs: ([]flatlang.Expr) (len=4 cap=4) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=4) "post"
      },
      (flatlang.MapNode) {
       Fields: ([]flatlang.Field) (len=2 cap=2) {
        (flatlang.Field) {
         Key: (string) (len=4) "path",
         Val: (flatlang.StringNode) {
          Val: (string) (len=6) "/posts"
         }
        },
        (flatlang.Field) {
         Key: (string) (len=13) "max_body_size",
         Val: (flatlang.IntNode) {
          Val: (int64) 128
         }
        }
       }
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=6) "decode"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=8) "new_post"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=6) "encode"
      }
     }
    }
   }
  },
  (flatlang.Stmt) {
   Type: (flatlang.StmtType) Call,
   Name: (string) "",
   Exprs: ([]flatlang.Expr) (len=3 cap=4) {
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "get"
      },
      (flatlang.StringNode) {
       Val: (string) (len=7) "/health"
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=2 cap=2) {
      (flatlang.IdentNode) {
       Val: (string) (len=3) "set"
      },
      (flatlang.MapNode) {
       Fields: ([]flatlang.Field) (len=1 cap=1) {
        (flatlang.Field) {
         Key: (string) (len=6) "status",
         Val: (flatlang.StringNode) {
          Val: (string) (len=2) "ok"
         }
        }
       }
      }
     }
    },
    (flatlang.Expr) {
     Nodes: ([]flatlang.Node) (len=1 cap=1) {
      (flatlang.IdentNode) {
       Val: (string) (len=6) "encode"
      }
     }
    }
   }
  }
 }
}

example.fbs

// Database URL.

db = 'sqlite://:memory:';

// SQL query handlers.

all_posts = sql db 'select * from posts limit :limit offset :offset' 'posts';
find_post = sql db 'select * from posts where id = :id' 'post';
new_post  = sql db 'insert into posts (author, content) values (:author, :content) returning id' 'id';

// An example expanded-form of a SQL query.

expanded_form = sql {db: db, query: 'select * from posts limit :limit offset :offset', set: 'posts'};

// Pagination helper.

paginate =
    > default {offset: 0, limit: 1024}
    > require {offset: >=0, limit: >=0 & <=1024}
    > set ['limit', 'offset'];

// GET "/posts" returns at most 1024 posts.

get "/posts"
	> paginate
	> find_post
	> encode;

// GET "/posts/:id" returns a post with a specific id = ":id".

get "/posts/:id"
    > find_post
    > encode;

// POST "/posts" creates a new post. Author and content must be provided.

post {path: "/posts", max_body_size: 128}
	> decode
	> new_post
	> encode;

// A simple health check endpoint that returns {status: "ok"}.

get "/health" > set {status: "ok"} > encode;