hy/tests/test_lex.py

# Copyright 2018 the authors.
# This file is part of Hy, which is free software licensed under the Expat
# license. See the LICENSE.

from math import isnan
from hy.models import (HyExpression, HyInteger, HyFloat, HyComplex, HySymbol,
                       HyString, HyDict, HyList, HySet, HyKeyword)
from hy.lex import LexException, PrematureEndOfInput, tokenize
import pytest

def peoi(): return pytest.raises(PrematureEndOfInput)
def lexe(): return pytest.raises(LexException)


def test_lex_exception():
    """ Ensure tokenize throws a fit on a partial input """
    with peoi(): tokenize("(foo")
    with peoi(): tokenize("{foo bar")
    with peoi(): tokenize("(defn foo [bar]")
    with peoi(): tokenize("(foo \"bar")


def test_unbalanced_exception():
    """Ensure the tokenization fails on unbalanced expressions"""
    with lexe(): tokenize("(bar))")
    with lexe(): tokenize("(baz [quux]])")


def test_lex_single_quote_err():
    "Ensure tokenizing \"' \" throws a LexException that can be stringified"
    # https://github.com/hylang/hy/issues/1252
    with lexe() as e: tokenize("' ")
    assert "Could not identify the next token" in str(e.value)


def test_lex_expression_symbols():
    """ Make sure that expressions produce symbols """
    objs = tokenize("(foo bar)")
    assert objs == [HyExpression([HySymbol("foo"), HySymbol("bar")])]


def test_lex_expression_strings():
    """ Test that expressions can produce strings """
    objs = tokenize("(foo \"bar\")")
    assert objs == [HyExpression([HySymbol("foo"), HyString("bar")])]


def test_lex_expression_integer():
    """ Make sure expressions can produce integers """
    objs = tokenize("(foo 2)")
    assert objs == [HyExpression([HySymbol("foo"), HyInteger(2)])]


def test_lex_symbols():
    """ Make sure that symbols are valid expressions"""
    objs = tokenize("foo ")
    assert objs == [HySymbol("foo")]


def test_lex_strings():
    """ Make sure that strings are valid expressions"""
    objs = tokenize('"foo"')
    assert objs == [HyString("foo")]
    # Make sure backslash-escaped newlines work (see issue #831)
    objs = tokenize(r"""
"a\
bc"
""")
    assert objs == [HyString("abc")]


def test_lex_strings_exception():
    """ Make sure tokenize throws when codec can't decode some bytes"""
    with lexe() as execinfo:
        tokenize('\"\\x8\"')
    assert "Can't convert \"\\x8\" to a HyString" in str(execinfo.value)


def test_lex_bracket_strings():

    objs = tokenize("#[my delim[hello world]my delim]")
    assert objs == [HyString("hello world")]
    assert objs[0].brackets == "my delim"

    objs = tokenize("#[[squid]]")
    assert objs == [HyString("squid")]
    assert objs[0].brackets == ""


def test_lex_integers():
    """ Make sure that integers are valid expressions"""
    objs = tokenize("42 ")
    assert objs == [HyInteger(42)]


def test_lex_fractions():
    """ Make sure that fractions are valid expressions"""
    objs = tokenize("1/2")
    assert objs == [HyExpression([HySymbol("fraction"), HyInteger(1),
                                  HyInteger(2)])]


def test_lex_expression_float():
    """ Make sure expressions can produce floats """
    objs = tokenize("(foo 2.)")
    assert objs == [HyExpression([HySymbol("foo"), HyFloat(2.)])]
    objs = tokenize("(foo -0.5)")
    assert objs == [HyExpression([HySymbol("foo"), HyFloat(-0.5)])]
    objs = tokenize("(foo 1.e7)")
    assert objs == [HyExpression([HySymbol("foo"), HyFloat(1.e7)])]


def test_lex_big_float():
    # https://github.com/hylang/hy/issues/1448
    assert tokenize("1e900") == [HyFloat(1e900)]
    assert tokenize("1e900-1e900j") == [HyComplex(1e900, -1e900)]


def test_lex_nan_and_inf():

    assert isnan(tokenize("NaN")[0])
    assert tokenize("Nan") == [HySymbol("Nan")]
    assert tokenize("nan") == [HySymbol("nan")]
    assert tokenize("NAN") == [HySymbol("NAN")]

    assert tokenize("Inf") == [HyFloat(float("inf"))]
    assert tokenize("inf") == [HySymbol("inf")]
    assert tokenize("INF") == [HySymbol("INF")]

    assert tokenize("-Inf") == [HyFloat(float("-inf"))]
    assert tokenize("-inf") == [HySymbol("-inf")]
    assert tokenize("-INF") == [HySymbol("-INF")]


def test_lex_expression_complex():
    """ Make sure expressions can produce complex """

    def t(x): return tokenize("(foo {})".format(x))

    def f(x): return [HyExpression([HySymbol("foo"), x])]

    assert t("2.j") == f(HyComplex(2.j))
    assert t("-0.5j") == f(HyComplex(-0.5j))
    assert t("1.e7j") == f(HyComplex(1e7j))
    assert t("j") == f(HySymbol("j"))
    assert isnan(t("NaNj")[0][1].imag)
    assert t("nanj") == f(HySymbol("nanj"))
    assert t("Inf+Infj") == f(HyComplex(complex(float("inf"), float("inf"))))
    assert t("Inf-Infj") == f(HyComplex(complex(float("inf"), float("-inf"))))
    assert t("Inf-INFj") == f(HySymbol("Inf-INFj"))


def test_lex_digit_separators():

    assert tokenize("1_000_000") == [HyInteger(1000000)]
    assert tokenize("1,000,000") == [HyInteger(1000000)]
    assert tokenize("1,000_000") == [HyInteger(1000000)]
    assert tokenize("1_000,000") == [HyInteger(1000000)]

    assert tokenize("0x_af") == [HyInteger(0xaf)]
    assert tokenize("0x,af") == [HyInteger(0xaf)]
    assert tokenize("0b_010") == [HyInteger(0b010)]
    assert tokenize("0b,010") == [HyInteger(0b010)]
    assert tokenize("0o_373") == [HyInteger(0o373)]
    assert tokenize("0o,373") == [HyInteger(0o373)]

    assert tokenize('1_2.3,4') == [HyFloat(12.34)]
    assert tokenize('1_2e3,4') == [HyFloat(12e34)]
    assert (tokenize("1,2/3_4") ==
            [HyExpression([HySymbol("fraction"),
             HyInteger(12), HyInteger(34)])])
    assert tokenize("1,0_00j") == [HyComplex(1000j)]

    assert tokenize("1,,,,___,____,,__,,2__,,,__") == [HyInteger(12)]
    assert (tokenize("_1,,,,___,____,,__,,2__,,,__") ==
            [HySymbol("_1,,,,___,____,,__,,2__,,,__")])
    assert (tokenize("1,,,,___,____,,__,,2__,q,__") ==
            [HySymbol("1,,,,___,____,,__,,2__,q,__")])


def test_lex_bad_attrs():
    with lexe(): tokenize("1.foo")
    with lexe(): tokenize("0.foo")
    with lexe(): tokenize("1.5.foo")
    with lexe(): tokenize("1e3.foo")
    with lexe(): tokenize("5j.foo")
    with lexe(): tokenize("3+5j.foo")
    with lexe(): tokenize("3.1+5.1j.foo")
    assert tokenize("j.foo")
    with lexe(): tokenize("3/4.foo")
    assert tokenize("a/1.foo")
    assert tokenize("1/a.foo")
    with lexe(): tokenize(":hello.foo")


def test_lex_line_counting():
    """ Make sure we can count lines / columns """
    entry = tokenize("(foo (one two))")[0]

    assert entry.start_line == 1
    assert entry.start_column == 1

    assert entry.end_line == 1
    assert entry.end_column == 15

    entry = entry[1]
    assert entry.start_line == 1
    assert entry.start_column == 6

    assert entry.end_line == 1
    assert entry.end_column == 14


def test_lex_line_counting_multi():
    """ Make sure we can do multi-line tokenization """
    entries = tokenize("""
(foo (one two))
(foo bar)
""")

    entry = entries[0]

    assert entry.start_line == 2
    assert entry.start_column == 1

    assert entry.end_line == 2
    assert entry.end_column == 15

    entry = entries[1]
    assert entry.start_line == 3
    assert entry.start_column == 1

    assert entry.end_line == 3
    assert entry.end_column == 9


def test_lex_line_counting_multi_inner():
    """ Make sure we can do multi-line tokenization (inner) """
    entry = tokenize("""(foo
    bar)""")[0]
    inner = entry[0]

    assert inner.start_line == 1
    assert inner.start_column == 2

    inner = entry[1]

    assert inner.start_line == 2
    assert inner.start_column == 5


def test_dicts():
    """ Ensure that we can tokenize a dict. """
    objs = tokenize("{foo bar bar baz}")
    assert objs == [HyDict(["foo", "bar", "bar", "baz"])]

    objs = tokenize("(bar {foo bar bar baz})")
    assert objs == [HyExpression([HySymbol("bar"),
                                  HyDict(["foo", "bar",
                                          "bar", "baz"])])]

    objs = tokenize("{(foo bar) (baz quux)}")
    assert objs == [HyDict([
        HyExpression([HySymbol("foo"), HySymbol("bar")]),
        HyExpression([HySymbol("baz"), HySymbol("quux")])
    ])]


def test_sets():
    """ Ensure that we can tokenize a set. """
    objs = tokenize("#{1 2}")
    assert objs == [HySet([HyInteger(1), HyInteger(2)])]
    objs = tokenize("(bar #{foo bar baz})")
    assert objs == [HyExpression([HySymbol("bar"),
                                  HySet(["foo", "bar", "baz"])])]

    objs = tokenize("#{(foo bar) (baz quux)}")
    assert objs == [HySet([
        HyExpression([HySymbol("foo"), HySymbol("bar")]),
        HyExpression([HySymbol("baz"), HySymbol("quux")])
    ])]

    # Duplicate items in a literal set should be okay (and should
    # be preserved).
    objs = tokenize("#{1 2 1 1 2 1}")
    assert objs == [HySet([HyInteger(n) for n in [1, 2, 1, 1, 2, 1]])]
    assert len(objs[0]) == 6

    # https://github.com/hylang/hy/issues/1120
    objs = tokenize("#{a 1}")
    assert objs == [HySet([HySymbol("a"), HyInteger(1)])]


def test_nospace():
    """ Ensure we can tokenize without spaces if we have to """
    entry = tokenize("(foo(one two))")[0]

    assert entry.start_line == 1
    assert entry.start_column == 1

    assert entry.end_line == 1
    assert entry.end_column == 14

    entry = entry[1]
    assert entry.start_line == 1
    assert entry.start_column == 5

    assert entry.end_line == 1
    assert entry.end_column == 13


def test_escapes():
    """ Ensure we can escape things """
    entry = tokenize(r"""(foo "foo\n")""")[0]
    assert entry[1] == "foo\n"

    entry = tokenize(r"""(foo r"foo\s")""")[0]
    assert entry[1] == r"foo\s"


def test_unicode_escapes():
    """Ensure unicode escapes are handled correctly"""
    s = r'"a\xac\u1234\u20ac\U00008000"'
    assert len(s) == 29
    entry = tokenize(s)[0]
    assert len(entry) == 5
    assert [ord(x) for x in entry] == [97, 172, 4660, 8364, 32768]


def test_complex():
    """Ensure we tokenize complex numbers properly"""
    # This is a regression test for #143
    entry = tokenize("(1j)")[0][0]
    assert entry == HyComplex("1.0j")
    entry = tokenize("(j)")[0][0]
    assert entry == HySymbol("j")


def test_tag_macro():
    """Ensure tag macros are handled properly"""
    entry = tokenize("#^()")
    assert entry[0][0] == HySymbol("dispatch-tag-macro")
    assert entry[0][1] == HyString("^")
    assert len(entry[0]) == 3


def test_lex_comment_382():
    """Ensure that we can tokenize sources with a comment at the end"""
    entry = tokenize("foo ;bar\n;baz")
    assert entry == [HySymbol("foo")]


def test_discard():
    """Check that discarded terms are removed properly."""
    # empty
    assert tokenize("") == []
    # single
    assert tokenize("#_1") == []
    # multiple
    assert tokenize("#_1 #_2") == []
    assert tokenize("#_1 #_2 #_3") == []
    # nested discard
    assert tokenize("#_ #_1 2") == []
    assert tokenize("#_ #_ #_1 2 3") == []
    # trailing
    assert tokenize("0") == [0]
    assert tokenize("0 #_1") == [0]
    assert tokenize("0 #_1 #_2") == [0]
    # leading
    assert tokenize("2") == [2]
    assert tokenize("#_1 2") == [2]
    assert tokenize("#_0 #_1 2") == [2]
    assert tokenize("#_ #_0 1 2") == [2]
    # both
    assert tokenize("#_1 2 #_3") == [2]
    assert tokenize("#_0 #_1 2 #_ #_3 4") == [2]
    # inside
    assert tokenize("0 #_1 2") == [0, 2]
    assert tokenize("0 #_1 #_2 3") == [0, 3]
    assert tokenize("0 #_ #_1 2 3") == [0, 3]
    # in HyList
    assert tokenize("[]") == [HyList([])]
    assert tokenize("[#_1]") == [HyList([])]
    assert tokenize("[#_1 #_2]") == [HyList([])]
    assert tokenize("[#_ #_1 2]") == [HyList([])]
    assert tokenize("[0]") == [HyList([HyInteger(0)])]
    assert tokenize("[0 #_1]") == [HyList([HyInteger(0)])]
    assert tokenize("[0 #_1 #_2]") == [HyList([HyInteger(0)])]
    assert tokenize("[2]") == [HyList([HyInteger(2)])]
    assert tokenize("[#_1 2]") == [HyList([HyInteger(2)])]
    assert tokenize("[#_0 #_1 2]") == [HyList([HyInteger(2)])]
    assert tokenize("[#_ #_0 1 2]") == [HyList([HyInteger(2)])]
    # in HySet
    assert tokenize("#{}") == [HySet()]
    assert tokenize("#{#_1}") == [HySet()]
    assert tokenize("#{0 #_1}") == [HySet([HyInteger(0)])]
    assert tokenize("#{#_1 0}") == [HySet([HyInteger(0)])]
    # in HyDict
    assert tokenize("{}") == [HyDict()]
    assert tokenize("{#_1}") == [HyDict()]
    assert tokenize("{#_0 1 2}") == [HyDict([HyInteger(1), HyInteger(2)])]
    assert tokenize("{1 #_0 2}") == [HyDict([HyInteger(1), HyInteger(2)])]
    assert tokenize("{1 2 #_0}") == [HyDict([HyInteger(1), HyInteger(2)])]
    # in HyExpression
    assert tokenize("()") == [HyExpression()]
    assert tokenize("(#_foo)") == [HyExpression()]
    assert tokenize("(#_foo bar)") == [HyExpression([HySymbol("bar")])]
    assert tokenize("(foo #_bar)") == [HyExpression([HySymbol("foo")])]
    assert tokenize("(foo :bar 1)") == [HyExpression([HySymbol("foo"), HyKeyword("bar"), HyInteger(1)])]
    assert tokenize("(foo #_:bar 1)") == [HyExpression([HySymbol("foo"), HyInteger(1)])]
    assert tokenize("(foo :bar #_1)") == [HyExpression([HySymbol("foo"), HyKeyword("bar")])]
    # discard term with nesting
    assert tokenize("[1 2 #_[a b c [d e [f g] h]] 3 4]") == [
        HyList([HyInteger(1), HyInteger(2), HyInteger(3), HyInteger(4)])
    ]
    # discard with other prefix syntax
    assert tokenize("a #_'b c") == [HySymbol("a"), HySymbol("c")]
    assert tokenize("a '#_b c") == [HySymbol("a"), HyExpression([HySymbol("quote"), HySymbol("c")])]
    assert tokenize("a '#_b #_c d") == [HySymbol("a"), HyExpression([HySymbol("quote"), HySymbol("d")])]
    assert tokenize("a '#_ #_b c d") == [HySymbol("a"), HyExpression([HySymbol("quote"), HySymbol("d")])]