Delta: An Incremental Compiler
Step 1: Decimal Integer Literals

Description

Add support for integer literals in base 10. A decimal integer literal is a sequence of one or more decimal digits.

The range of these literals should be: \([0, 2^{31})\). Anything outside this range should raise a delta.SemanticMistake exception.

Example

The Delta program:

42

should produce the following WAT code:

(module
  (func
    (export "_start")
    (result i32)
    i32.const 42
  )
)

The above WAT function’s return value should be:

42

Unit Tests

# File: tests/test_01_decimal.py

from unittest import TestCase
from delta import Compiler, SyntaxMistake
from delta.semantics import SemanticMistake


class TestIntLiteral(TestCase):

    def setUp(self):
        self.c = Compiler('program')

    def test_syntax_mistake(self):
        with self.assertRaises(SyntaxMistake):
            self.c.realize('$1')

    def test_0(self):
        self.assertEqual(
            0,
            self.c.realize('0'))

    def test_42(self):
        self.assertEqual(
            42,
            self.c.realize('42'))

    def test_1000000(self):
        self.assertEqual(
            1000000,
            self.c.realize('1000000'))

    def test_max_int(self):
        self.assertEqual(
            2147483647,
            self.c.realize('2147483647'))

    def test_int_overflow(self):
        with self.assertRaises(SemanticMistake):
            self.c.realize('2147483648')

    def test_int_huge_overflow(self):
        with self.assertRaises(SemanticMistake):
            self.c.realize('340282366920938463463374607431768211455')