Warn when zero-prefixed numbers are used

Resolves #25

hera/config.py

@@ -0,0 +1,16 @@
+LINES = None
+
+
+# ANSI color codes (https://stackoverflow.com/questions/4842424/)
+# When the --no-color flag is specified, these constants are set to the empty
+# string, so they can be used unconditionally in your code but will still obey
+# the flag value.
+
+
+def _make_ansi(*params):
+    return "\033[" + ";".join(map(str, params)) + "m"
+
+
+ANSI_RED_BOLD = _make_ansi(31, 1)
+ANSI_MAGENTA_BOLD = _make_ansi(35, 1)
+ANSI_RESET = _make_ansi(0)

hera/main.py

@@ -18,15 +18,15 @@
 
 from docopt import docopt
 
-from . import utils
+from . import config
 from .parser import parse
 from .preprocessor import preprocess
 from .typechecker import typecheck
-from .utils import print_register_debug, HERAError
+from .utils import emit_error, print_register_debug, HERAError
 from .vm import VirtualMachine
 
 
-lines = None
+LINES = None
 
 
 def main(argv=None, vm=None):
@@ -41,7 +41,7 @@ def main(argv=None, vm=None):
     path = arguments["<path>"]
 
     if arguments["--no-color"]:
-        utils.ANSI_MAGENTA_BOLD = utils.ANSI_RED_BOLD = utils.ANSI_RESET = ""
+        config.ANSI_MAGENTA_BOLD = config.ANSI_RED_BOLD = config.ANSI_RESET = ""
 
     if path == "-":
         try:
@@ -86,42 +86,28 @@ def execute_program(program, *, lines_to_exec=None, no_dump_state=False, vm=None
     A virtual machine instance may be passed in for testing purposes. If it is not, a
     new one is instantiated. The virtual machine is returned.
     """
-    lines = program.splitlines()
+    config.LINES = program.splitlines()
 
     if vm is None:
         vm = VirtualMachine()
 
     try:
         program = parse(program)
     except HERAError as e:
-        report_hera_error(e, lines)
+        emit_error(str(e), line=e.line, column=e.column, exit=True)
 
     # TODO: Seems like typechecking should happen after preprocessing.
     errors = typecheck(program)
     if errors:
         for error in errors:
-            # TODO: Remove duplication with report_hera_error and error_and_exit.
-            if error.line:
-                if error.column:
-                    caret = align_caret(lines[error.line - 1], error.column) + "^"
-                    msg = "{0.msg}, line {0.line} col {0.column}\n\n  {1}\n  {2}\n".format(
-                        error, lines[error.line - 1], caret
-                    )
-                else:
-                    msg = "{0.msg}, line {0.line}\n\n  {1}\n".format(
-                        error, lines[error.line - 1]
-                    )
-            else:
-                msg = error.msg
-            sys.stderr.write(utils.ANSI_RED_BOLD + "Error" + utils.ANSI_RESET + ": ")
-            sys.stderr.write(msg + "\n")
+            emit_error(error.msg, line=error.line, column=error.column)
         sys.exit(3)
 
     try:
         program = preprocess(program)
         vm.exec_many(program, lines=lines_to_exec)
     except HERAError as e:
-        report_hera_error(e, lines)
+        emit_error(str(e), line=e.line, column=e.column, exit=True)
     else:
         if not no_dump_state:
             dump_state(vm)
@@ -161,30 +147,3 @@ def dump_state(vm):
     nprint("\tOverflow flag is " + ("ON" if vm.flag_overflow else "OFF"))
     nprint("\tCarry flag is " + ("ON" if vm.flag_carry else "OFF"))
     nprint("\tCarry block flag is " + ("ON" if vm.flag_carry_block else "OFF"))
-
-
-def report_hera_error(exc, lines):
-    if exc.line:
-        if exc.column:
-            caret = align_caret(lines[exc.line - 1], exc.column) + "^"
-            msg = "{0}, line {0.line} col {0.column}\n\n  {1}\n  {2}\n".format(
-                exc, lines[exc.line - 1], caret
-            )
-        else:
-            msg = "{0}, line {0.line}\n\n  {1}\n".format(exc, lines[exc.line - 1])
-    else:
-        msg = str(exc)
-    error_and_exit(msg)
-
-
-def error_and_exit(msg, *, exitcode=3):
-    sys.stderr.write(utils.ANSI_RED_BOLD + "Error" + utils.ANSI_RESET + ": ")
-    sys.stderr.write(msg + "\n")
-    sys.exit(exitcode)
-
-
-def align_caret(line, col):
-    """Return the whitespace necessary to align a caret to underline the desired
-    column in the line of text. Mainly this means handling tabs.
-    """
-    return "".join("\t" if c == "\t" else " " for c in line[: col - 1])

hera/parser.py

@@ -31,7 +31,11 @@ def value(self, matches):
             return IntToken(matches[0], base=16, line=line, column=column)
         elif matches[0].type == "OCTAL":
             if not matches[0].startswith("0o"):
-                emit_warning("zero-prefixed numbers are interpreted as octal")
+                emit_warning(
+                    "zero-prefixed numbers are interpreted as octal",
+                    line=matches[0].line,
+                    column=matches[0].column,
+                )
             return IntToken(matches[0], base=8, line=line, column=column)
         elif matches[0].type == "BINARY":
             return IntToken(matches[0], base=2, line=line, column=column)

hera/utils.py

@@ -7,6 +7,8 @@
 
 from lark import Token
 
+from . import config
+
 
 class HERAError(Exception):
     def __init__(self, msg, line=None, column=None):
@@ -105,20 +107,34 @@ def is_symbol(s):
     return isinstance(s, Token) and s.type == "SYMBOL"
 
 
-def emit_warning(msg):
-    sys.stderr.write(ANSI_MAGENTA_BOLD + "Warning" + ANSI_RESET + ": " + msg + "\n")
+def emit_error(msg, *, line=None, column=None, exit=False):
+    """Print an error message to stderr."""
+    msg = config.ANSI_RED_BOLD + "Error" + config.ANSI_RESET + ": " + msg
+    _emit_msg(msg, line=line, column=column, exit=exit)
 
 
-# ANSI color codes (https://stackoverflow.com/questions/4842424/)
-# When the --no-color flag is specified, these constants are set to the empty
-# string, so they can be used unconditionally in your code but will still obey
-# the flag value.
+def emit_warning(msg, *, line=None, column=None):
+    """Print a error warning to stderr."""
+    msg = config.ANSI_MAGENTA_BOLD + "Warning" + config.ANSI_RESET + ": " + msg
+    _emit_msg(msg, line=line, column=column, exit=False)
 
 
-def make_ansi(*params):
-    return "\033[" + ";".join(map(str, params)) + "m"
+def _emit_msg(msg, *, line=None, column=None, exit=False):
+    if line is not None and config.LINES is not None:
+        if column is not None:
+            caret = _align_caret(config.LINES[line - 1], column) + "^"
+            msg += ", line {} col {}\n\n  {}\n  {}\n".format(
+                line, column, config.LINES[line - 1], caret
+            )
+        else:
+            msg += ", line {}\n\n  {}\n".format(line, config.LINES[line - 1])
+    sys.stderr.write(msg + "\n")
+    if exit:
+        sys.exit(exit)
 
 
-ANSI_RED_BOLD = make_ansi(31, 1)
-ANSI_MAGENTA_BOLD = make_ansi(35, 1)
-ANSI_RESET = make_ansi(0)
+def _align_caret(line, col):
+    """Return the whitespace necessary to align a caret to underline the desired
+    column in the line of text. Mainly this means handling tabs.
+    """
+    return "".join("\t" if c == "\t" else " " for c in line[: col - 1])

test/test_config.py

@@ -0,0 +1,9 @@
+from hera.config import _make_ansi
+
+
+def test_make_ansi_red():
+    assert _make_ansi(31, 1) == "\033[31;1m"
+
+
+def test_make_ansi_reset():
+    assert _make_ansi(0) == "\033[0m"

test/test_main.py

@@ -1,14 +1,8 @@
-from hera.main import (
-    align_caret,
-    dump_state,
-    op_to_string,
-    program_to_string,
-)
+from hera.main import dump_state, op_to_string, program_to_string
 from hera.parser import Op
 from hera.vm import VirtualMachine
 
 
-
 def test_op_to_string():
     assert op_to_string(Op("SET", ["R1", "top"])) == "SET(R1, top)"
 
@@ -26,10 +20,6 @@ def test_program_to_string():
     assert program_to_string(program) == "SET(R1, 20)\nSET(R2, 22)\nADD(R3, R1, R2)"
 
 
-def test_align_caret():
-    assert align_caret("\t\t  a", 5) == "\t\t  "
-
-
 def test_dump_state(capsys):
     dump_state(VirtualMachine())
 

test/test_utils.py

@@ -1,14 +1,6 @@
 import pytest
 
-from hera.utils import from_u16, make_ansi, register_to_index, to_u16, to_u32
-
-
-def test_make_ansi_red():
-    assert make_ansi(31, 1) == "\033[31;1m"
-
-
-def test_make_ansi_reset():
-    assert make_ansi(0) == "\033[0m"
+from hera.utils import from_u16, register_to_index, to_u16, to_u32, _align_caret
 
 
 def test_to_u16_with_max_negative():
@@ -154,3 +146,7 @@ def test_register_to_index_with_invalid_register():
     with pytest.raises(ValueError) as e:
         register_to_index("R16")
     assert "R16" in str(e)
+
+
+def test_align_caret():
+    assert _align_caret("\t\t  a", 5) == "\t\t  "