from efilter import api
api.apply("5 + 5") # => 10

# Returns [{"name": "Alice"}, {"name": "Eve"}]
api.apply("SELECT name FROM users WHERE age > 10",
          vars={"users": ({"age": 10, "name": "Bob"},
                          {"age": 20, "name": "Alice"},
                          {"age": 30, "name": "Eve"}))

# Step 1: have a custom class.

class MyUser(object):
    ...

# Step 2: Implement a protocol (like an interface).

from efilter.protocols import structured
structured.IStructured.implement(
    for_type=MyUser,
    implementations: {
        structured.resolve: lambda user, key: getattr(user, key)
    }
)

# Step 3: EFILTER can now use my class!
from efilter import api
api.apply("SELECT name FROM users WHERE age > 10 ORDER BY age",
          vars={"users": [MyUser(...), MyUser(...)]})

# Replacements are applied before the query is compiled.
search_term = dangerous_user_input["name"]
api.apply("SELECT * FROM users WHERE name = ?",
          vars={"users": [...]},
          replacements=[search_term])

# We also support keyword replacements.
api.apply("SELECT * FROM users WHERE name = {name}",
          vars={"users": [...]},
          replacements={"name": search_term})

# Builtin IO functions need to be explicitly enabled.
api.apply("SELECT * FROM csv(users.csv) WHERE name = 'Bob'", allow_io=True)