# -- USE CASE:
def parse_number(text):
    return int(text)
parse_number.pattern = r"\d+"  # -- REGULAR EXPRESSION pattern for type.

import parse

@parse.with_pattern(r"\d+")
def parse_number(text):
     return int(text)
assert hasattr(parse_number, "pattern")
assert parse_number.pattern == r"\d+"

# -- USE CASE: Use the type converter with the parse module.
schema = "Hello {number:Number}"
parser = parse.Parser(schema, dict(Number=parse_number))
result = parser.parse("Hello 42")
assert result is not None, "REQUIRE: text matches the schema."
assert result["number"] == 42

result = parser.parse("Hello XXX")
assert result is None, "MISMATCH: text does not match the schema."

# -- USE CASE: Create new type converter with a cardinality constraint.
# CARDINALITY: many := one or more (1..*)
from parse import Parser
from parse_type import TypeBuilder
parse_numbers = TypeBuilder.with_many(parse_number, listsep=",")

schema = "List: {numbers:ManyNumbers}"
parser = Parser(schema, dict(ManyNumbers=parse_numbers))
result = parser.parse("List: 1, 2, 3")
assert result["numbers"] == [1, 2, 3]

# -- USE CASE: Create new type converter with cardinality constraint.
# CARDINALITY: optional := zero or one (0..1)
from parse import Parser
from parse_type import TypeBuilder

parse_optional_number = TypeBuilder.with_optional(parse_number)
schema = "Optional: {number:OptionalNumber}"
parser = Parser(schema, dict(OptionalNumber=parse_optional_number))
result = parser.parse("Optional: 42")
assert result["number"] == 42
result = parser.parse("Optional: ")
assert result["number"] == None

# -- USE CASE: Create a type converter for an enumeration.
from parse import Parser
from parse_type import TypeBuilder

parse_enum_yesno = TypeBuilder.make_enum({"yes": True, "no": False})
parser = Parser("Answer: {answer:YesNo}", dict(YesNo=parse_enum_yesno))
result = parser.parse("Answer: yes")
assert result["answer"] == True

# -- USE CASE: Create a type converter for enum34 enumeration class.
# NOTE: Use Python 3.4 or enum34 backport.
from parse import Parser
from parse_type import TypeBuilder
from enum import Enum

class Color(Enum):
    red   = 1
    green = 2
    blue  = 3

parse_enum_color = TypeBuilder.make_enum(Color)
parser = Parser("Select: {color:Color}", dict(Color=parse_enum_color))
result = parser.parse("Select: red")
assert result["color"] is Color.red

from parse import Parser
from parse_type import TypeBuilder

parse_choice_yesno = TypeBuilder.make_choice(["yes", "no"])
schema = "Answer: {answer:ChoiceYesNo}"
parser = Parser(schema, dict(ChoiceYesNo=parse_choice_yesno))
result = parser.parse("Answer: yes")
assert result["answer"] == "yes"

from parse import Parser, with_pattern
from parse_type import TypeBuilder
from enum import Enum

class Color(Enum):
    red   = 1
    green = 2
    blue  = 3

@with_pattern(r"\d+")
def parse_number(text):
    return int(text)

# -- MAKE VARIANT: Alternatives of different type converters.
parse_color = TypeBuilder.make_enum(Color)
parse_variant = TypeBuilder.make_variant([parse_number, parse_color])
schema = "Variant: {variant:Number_or_Color}"
parser = Parser(schema, dict(Number_or_Color=parse_variant))

# -- TEST VARIANT: With number, color and mismatch.
result = parser.parse("Variant: 42")
assert result["variant"] == 42
result = parser.parse("Variant: blue")
assert result["variant"] is Color.blue
result = parser.parse("Variant: __MISMATCH__")
assert not result

# -- USE CASE: Parser with CardinalityField support.
# NOTE: Automatically adds missing type variants with CardinalityField part.
# USE:  parse_number() type converter from above.
from parse_type.cfparse import Parser

# -- PREPARE: parser, adds missing type variant for cardinality 1..* (many)
type_dict = dict(Number=parse_number)
schema = "List: {numbers:Number+}"
parser = Parser(schema, type_dict)
assert "Number+" in type_dict, "Created missing type variant based on: Number"

# -- USE: parser.
result = parser.parse("List: 1, 2, 3")
assert result["numbers"] == [1, 2, 3]