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mirror of https://github.com/kanaka/mal.git synced 2024-10-27 14:52:16 +03:00
mal/impls/python.2/step2_eval.py
Nicolas Boulenguez 033892777a Merge eval-ast and macro expansion into EVAL, add DEBUG-EVAL
See issue #587.
* Merge eval-ast and eval into a single conditional.
* Expand macros during the apply phase, removing lots of duplicate
  tests, and increasing the overall consistency by allowing the macro
  to be computed instead of referenced by name (`((defmacro! cond
  (...)))` is currently illegal for example).
* Print "EVAL: $ast" at the top of EVAL if DEBUG-EVAL exists in the
  MAL environment.
* Remove macroexpand and quasiquoteexpand special forms.
* Use pattern-matching style in process/step*.txt.

Unresolved issues:
c.2: unable to reproduce with gcc 11.12.0.
elm: the directory is unchanged.
groovy: sometimes fail, but not on each rebuild.
nasm: fails some new soft tests, but the issue is unreproducible when
  running the interpreter manually.
objpascal: unreproducible with fpc 3.2.2.
ocaml: unreproducible with 4.11.1.
perl6: unreproducible with rakudo 2021.09.

Unrelated changes:
Reduce diff betweens steps.
Prevent defmacro! from mutating functions: c forth logo miniMAL vb.
dart: fix recent errors and warnings
ocaml: remove metadata from symbols.

Improve the logo implementation.
Encapsulate all representation in types.lg and env.lg, unwrap numbers.
Replace some manual iterations with logo control structures.
Reduce the diff between steps.
Use native iteration in env_get and env_map
Rewrite the reader with less temporary strings.
Reduce the number of temporary lists (for example, reverse iteration
with butlast requires O(n^2) allocations).
It seems possible to remove a few exceptions: GC settings
(Dockerfile), NO_SELF_HOSTING (IMPLS.yml) and step5_EXCLUDES
(Makefile.impls) .
2024-08-05 11:40:49 -05:00

67 lines
2.0 KiB
Python

import readline
from typing import Dict
import reader
from mal_types import MalExpression, MalSymbol
from mal_types import MalFunctionCompiled, MalInt
from mal_types import MalList, MalVector, MalHash_map
from mal_types import MalUnknownSymbolException, MalSyntaxException
repl_env = {
"+": MalFunctionCompiled(lambda a: MalInt(a[0].native() + a[1].native())),
"-": MalFunctionCompiled(lambda a: MalInt(a[0].native() - a[1].native())),
"*": MalFunctionCompiled(lambda a: MalInt(a[0].native() * a[1].native())),
"/": MalFunctionCompiled(lambda a: MalInt(int(a[0].native() / a[1].native()))),
}
def READ(x: str) -> MalExpression:
return reader.read(x)
def EVAL(ast: MalExpression, env: Dict[str, MalFunctionCompiled]) -> MalExpression:
# print("EVAL: " + str(ast))
if isinstance(ast, MalSymbol):
try:
return env[str(ast)]
except KeyError:
raise MalUnknownSymbolException(str(ast))
if isinstance(ast, MalVector):
return MalVector([EVAL(x, env) for x in ast.native()])
if isinstance(ast, MalHash_map):
new_dict = {} # type: Dict[str, MalExpression]
for key in ast.native():
new_dict[key] = EVAL(ast.native()[key], env)
return MalHash_map(new_dict)
if not isinstance(ast, MalList):
return ast
if len(ast.native()) == 0:
return ast
f, *args = (EVAL(form, env) for form in ast.native())
return f.call(args)
def PRINT(exp: MalExpression) -> str:
return str(exp)
def rep(x: str) -> str:
return PRINT(EVAL(READ(x), repl_env))
if __name__ == "__main__":
# repl loop
eof: bool = False
while not eof:
try:
line = input("user> ")
readline.add_history(line)
try:
print(rep(line))
except MalUnknownSymbolException as e:
print("'" + e.func + "' not found")
except MalSyntaxException as e:
print("ERROR: invalid syntax: " + str(e))
except EOFError:
eof = True