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author | Juan J. Martinez <jjm@usebox.net> | 2024-04-19 20:21:56 +0100 |
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committer | Juan J. Martinez <jjm@usebox.net> | 2024-04-19 20:25:26 +0100 |
commit | 044360219f2e4e0b5b5a95cb7ede00753340d61d (patch) | |
tree | 4c2341a6e4941b3c3b70ca9941699e8f84353901 | |
download | funco-044360219f2e4e0b5b5a95cb7ede00753340d61d.tar.gz funco-044360219f2e4e0b5b5a95cb7ede00753340d61d.zip |
Initial import
-rw-r--r-- | .gitignore | 5 | ||||
-rw-r--r-- | README.md | 110 | ||||
-rw-r--r-- | TODO.md | 5 | ||||
-rw-r--r-- | examples/fact.fco | 14 | ||||
-rw-r--r-- | examples/fib.fco | 13 | ||||
-rw-r--r-- | examples/for.fco | 11 | ||||
-rwxr-xr-x | funco | 356 | ||||
-rw-r--r-- | gpl-3.0.txt | 674 |
8 files changed, 1188 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..9d67b10 --- /dev/null +++ b/.gitignore @@ -0,0 +1,5 @@ +*.pyc +build +*.swp +*~ +.mypy_cache diff --git a/README.md b/README.md new file mode 100644 index 0000000..8815658 --- /dev/null +++ b/README.md @@ -0,0 +1,110 @@ +# Funco + +This is a small functional programming language I wrote for fun inspired by [lispy](https://norvig.com/lispy.html) and [Atto](https://github.com/zesterer/atto/tree/master). + +Still, it has a lexer and a parser, and some optimizations (like recursive tail calls, although they need to be tagged). + +The only requirement is Python 3.10 or later. + +There are lots of limitations, but check [TODO](TODO.md) for some ideas to contribute. + +## The language + +An example: + +```ruby +# example of a factorial function +def fact(n acc) + if =(n 1) + acc + else + # tagging a tail call with "@" so it can be optimized + @fact(-(n 1) *(acc n)) + end +end + +# main is the entry point of a program +def main() + display("Running fact(50)...") + display(fact(50. 1)) +end + +# output: +# Running fact(50)... +# 3.0414093201713376e+64 +``` + +A program can have: + +* line comments, with `#` +* function definitions +* expressions + +A `main()` function is required and will be executed as entry point for the program. + +Function definition: + +```text +def ident([param1 [param2] [...]]) + [...] +end +``` + +Expressions can be: + +* function calls +* conditionals with `if [elif [elif] [...]] [else]` +* literals + +Literals include: + +* numbers (int or float): `1`, `1.5` +* strings: `"this is a string"` +* booleans (true or false), as result of some logical functions; although 0 is false and non-zero is true +* lists +* functions +* none for "no value" + +Operators are functions, that includes: + +* `+`, `-`, `*`, `/` +* `>`, `<`, `>=`, `<=`, `=`, `!=` +* `and`, `or`, `not` + +For example, adding two numbers: + +```ruby ++(1 1) # should be 2 +``` + +Other built-in functions are: + +* `int(value)`: convert a value into a integer +* `float(value)`: convert a value into a float +* `string(value)`: convert a value into a string +* `list(a b c d)`: convert its arguments into a list, for example `list(1 2 3 4)` +* `int?(value)`: returns true if a value is a integer +* `float?(value)`: returns true if a value is a float +* `string?(value)`: returns true if a value is a string +* `list?(value)`: returns true if a values is a list +* `none?(value)`: returns true if a value is none +* `boolean?(value)`: returns true if a value is a boolean +* `function?(value)`: returns true if a value is a function +* `head(list)`: returns the first element of a list +* `tail(list)`: returns the end of a list excluding the first element +* `empty?(list)`: returns true if a list is empty +* `size(list)`: returns the size of a list +* `min(list)`: returns the smaller value in a list +* `max(list)`: returns the larger value in a list +* `contains(value list)`: returns true if a list contains a value +* `map(fn list)`: applies a list to a function +* `filter(fn list)`: applies a list to a function, excluding the items for which the function returns true +* `fold(initial fn list)`: folds using a function the receives the accumulator and the value, and returns the updated accumulator +* `take(n list)`: return the first n elements of a list +* `drop(n list)`: return the list dropping the n first elements +* `display(value)`: prints its arguments to the screen, for example `display("hello" "world")` + +## Licence + +* This project is licensed [GPL 3.0](gpl-3.0.txt). + @@ -0,0 +1,5 @@ +* improve error reporting + * probably wrapping the tokens in an object -- what will be the impact in performance? +* write tests? +* more examples +* an Funco interpreter in Funco? diff --git a/examples/fact.fco b/examples/fact.fco new file mode 100644 index 0000000..6eccca9 --- /dev/null +++ b/examples/fact.fco @@ -0,0 +1,14 @@ +# Factorial of a number +def fact(n acc) + if =(n 1) + acc + else + # tagging a tail call with "@" so it can be optimized + @fact(-(n 1) *(acc n)) + end +end + +def main() + display("Running fact(50)...") + display(fact(50. 1)) +end diff --git a/examples/fib.fco b/examples/fib.fco new file mode 100644 index 0000000..d459341 --- /dev/null +++ b/examples/fib.fco @@ -0,0 +1,13 @@ +# fibonacci number +def fib(n) + if <(n 2) + n + else + +(fib(- (n 1)) fib(- (n 2))) + end +end + +def main() + display("Running fib(20)...") + display(fib(20)) +end diff --git a/examples/for.fco b/examples/for.fco new file mode 100644 index 0000000..9710fe2 --- /dev/null +++ b/examples/for.fco @@ -0,0 +1,11 @@ +# recursive for loop +def for(n fn) + if >(n 0) + fn(n) + @for(-(n 1) fn) + end +end + +def main() + for(10000 display) +end @@ -0,0 +1,356 @@ +#!/usr/bin/python3 + +import operator +import itertools +from argparse import ArgumentParser + +__version__ = "0.1" + +Ident = str +List = list +Number = (int, float) + + +class String(str): + pass + + +class TailRec(Exception): + def __init__(self, ident, args): + self.ident = ident + self.args = args + + +class Env(dict): + def __init__(self, parms=(), args=(), parent=None): + self.update(zip(parms, args)) + self.parent = parent + + def find(self, var: str): + if var in self: + return self + else: + if self.parent: + return self.parent.find(var) + else: + raise ValueError(f"not found: {var}") + + +class Function(object): + def __init__(self, ident, parms, body): + self.ident = ident + self.parms = parms + self.body = body + self.env = None + + def with_env(self, env): + self.env = env + return self + + def __repr__(self): + return f"Function {self.ident} {self.parms} = {self.body}" + + def __call__(self, *args): + while True: + try: + call_env = Env(self.parms, args, self.env) + return eval_block(self.body, call_env) + except TailRec as tr: + if self.env.find(tr.ident)[tr.ident] != self: + raise RuntimeError("tagged tail call can't be optimized") + args = [eval(expr, call_env) for expr in tr.args] + + +class Call(object): + def __init__(self, ident, args): + self.ident = ident + self.args = args + self.tail_rec = False + + def __repr__(self): + return f"Call {self.ident} {self.args} (tail_rec: {self.tail_rec})" + + +class If(object): + def __init__(self, conds: list[list], otherwise=None): + self.conds = conds + self.otherwise = otherwise + + def __repr__(self): + out = "If" + for c, e in self.conds: + out += f" {c} -> {e}" + if self.otherwise: + out += f" else -> {self.otherwise}" + return out + + +def tokenize(program: str) -> list[str]: + single: str = "():@" + + i = 0 + while i < len(program): + if program[i].isspace(): + while i < len(program) and program[i].isspace(): + i += 1 + continue + + c = program[i] + if program[i] in single: + yield c + i += 1 + elif c == '"': + j = i + 1 + while j < len(program) and program[j] != '"': + j += 1 + if j == len(program): + raise SyntaxError('EOF in open string') + yield program[i:j + 1] + i = j + 1 + elif c == '#': + j = i + 1 + while j < len(program) and program[j] != '\n': + j += 1 + i = j + 1 + else: + j = i + while j < len(program) and ( + not program[j].isspace() and program[j] not in single + ): + j += 1 + yield program[i:j] + i = j + + +class Parser(object): + def __init__(self, tokens): + self.tokens = tokens + + def next(self): + return next(self.tokens) + + def peek(self): + n = self.next() + self.tokens = itertools.chain([n], self.tokens) + return n + + def expect(self, expected: str): + if self.next() != expected: + raise SyntaxError(f"{expected} expected") + + def parse_parms(self) -> list: + parms = [] + while True: + param = self.next() + if param == ")": + break + if param.isdigit() or not param.isalnum(): + raise SyntaxError("ident expected") + parms.append(param) + return parms + + def parse_function(self): + ident = self.next() + self.expect("(") + parms = self.parse_parms() + return Function(ident, parms, self.parse(in_block=True)) + + def parse_call(self, ident): + self.expect("(") + args = [] + while True: + arg = self.next() + if arg == ")": + break + args.append(self.parse_expr(arg)) + return Call(ident, args) + + def parse_tailrec(self): + ident = self.next() + c = self.parse_call(ident) + c.tail_rec = True + return c + + def parse_else(self): + exprs = [] + while True: + expr = self.next() + if expr == "end": + break + exprs.append(self.parse_expr(expr)) + return exprs + + def parse_if(self): + def new_cond(): + return [self.parse_expr(self.next()), []] + + conds = [new_cond()] + otherwise = None + while True: + token = self.next() + if token == "end": + break + if token == "elif": + conds.append(new_cond()) + continue + elif token == "else": + otherwise = self.parse_else() + break + else: + conds[-1][1].append(self.parse_expr(token)) + return If(conds, otherwise) + + def parse_expr(self, expr): + n = self.peek() + if expr == "@": + return self.parse_tailrec() + elif expr[0] == '"': + return String(expr[1:len(expr) - 1]) + elif expr == "if": + return self.parse_if() + elif n == "(": + return self.parse_call(expr) + try: + return int(expr) + except ValueError: + try: + return float(expr) + except ValueError: + return Ident(expr) + + def parse(self, in_block: bool = False) -> list: + try: + self.peek() + except StopIteration: + raise SyntaxError("unexpected EOF") + + out: list = [] + try: + while True: + match self.next(): + case "def": + out.append(self.parse_function()) + case "end": + if in_block: + return out + else: + raise SyntaxError("end not in open block") + case expr: + out.append(self.parse_expr(expr)) + except StopIteration: + return out + + +def eval_block(exprs, env): + for expr in exprs: + result = eval(expr, env) + return result + + +def eval(x, env): + if isinstance(x, String): + return x + elif isinstance(x, Ident): + return env.find(x)[x] + elif isinstance(x, Function): + env[x.ident] = x.with_env(env) + elif isinstance(x, If): + for cond, exprs in x.conds: + if eval(cond, env) != 0: + return eval_block(exprs, env) + if x.otherwise: + return eval_block(x.otherwise, env) + elif isinstance(x, Call): + fn = eval(x.ident, env) + args = [eval(expr, env) for expr in x.args] + if x.tail_rec: + raise TailRec(x.ident, x.args) + else: + return fn(*args) + else: + return x + + +def fold(acc, fn, xs): + for x in xs: + acc = fn(acc, x) + return acc + + +def default_env(): + env = Env() + env.update( + { + "+": operator.add, + "-": operator.sub, + "*": operator.mul, + "/": operator.truediv, + ">": operator.gt, + "<": operator.lt, + ">=": operator.ge, + "<=": operator.le, + "=": operator.eq, + "!=": operator.ne, + "and": operator.and_, + "or": operator.or_, + "not": operator.not_, + + "int": int, + "float": float, + "string": str, + "list": lambda *xs: list(xs), + "int?": lambda x: isinstance(x, int), + "float?": lambda x: isinstance(x, float), + "string?": lambda x: isinstance(x, str), + "list?": lambda x: isinstance(x, list), + "none?": lambda x: x is None, + "boolean?": lambda x: isinstance(x, bool), + "function?": lambda x: isinstance(x, Function), + + "head": lambda xs: xs[0], + "tail": lambda xs: xs[1:], + "empty?": lambda xs: xs == [], + "size": lambda xs: len(xs) if isinstance(xs, list) else None, + "min": lambda xs: min(xs) if isinstance(xs, list) else None, + "max": lambda xs: max(xs) if isinstance(xs, list) else None, + "contains": lambda x, xs: x in xs, + + "map": lambda f, xs: list(map(f, xs)), + "filter": lambda f, xs: list(filter(f, xs)), + "fold": fold, + "take": lambda n, xs: xs[:n], + "drop": lambda n, xs: xs[n:], + "display": print, + } + ) + return env + + +def main(): + parser = ArgumentParser( + description="Funco interpreter", + epilog="Copyright (C) 2024 Juan J. Martinez <jjm@usebox.net>", + ) + parser.add_argument( + "--version", action="version", version="%(prog)s " + __version__ + ) + parser.add_argument("file", help="program to execute") + + args = parser.parse_args() + + with open(args.file, "rt") as fd: + src = fd.read() + + tokens = tokenize(src) + parser = Parser(tokens) + ast = parser.parse() + env = default_env() + for expr in ast: + eval(expr, env) + if "main" not in env: + raise ValueError("main not found") + eval(env["main"](), env) + + +if __name__ == "__main__": + main() diff --git a/gpl-3.0.txt b/gpl-3.0.txt new file mode 100644 index 0000000..f288702 --- /dev/null +++ b/gpl-3.0.txt @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/> + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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No Surrender of Others' Freedom. + + If conditions are imposed on you (whether by court order, agreement or +otherwise) that contradict the conditions of this License, they do not +excuse you from the conditions of this License. If you cannot convey a +covered work so as to satisfy simultaneously your obligations under this +License and any other pertinent obligations, then as a consequence you may +not convey it at all. For example, if you agree to terms that obligate you +to collect a royalty for further conveying from those to whom you convey +the Program, the only way you could satisfy both those terms and this +License would be to refrain entirely from conveying the Program. + + 13. Use with the GNU Affero General Public License. + + Notwithstanding any other provision of this License, you have +permission to link or combine any covered work with a work licensed +under version 3 of the GNU Affero General Public License into a single +combined work, and to convey the resulting work. The terms of this +License will continue to apply to the part which is the covered work, +but the special requirements of the GNU Affero General Public License, +section 13, concerning interaction through a network will apply to the +combination as such. + + 14. Revised Versions of this License. + + The Free Software Foundation may publish revised and/or new versions of +the GNU General Public License from time to time. Such new versions will +be similar in spirit to the present version, but may differ in detail to +address new problems or concerns. + + Each version is given a distinguishing version number. If the +Program specifies that a certain numbered version of the GNU General +Public License "or any later version" applies to it, you have the +option of following the terms and conditions either of that numbered +version or of any later version published by the Free Software +Foundation. If the Program does not specify a version number of the +GNU General Public License, you may choose any version ever published +by the Free Software Foundation. + + If the Program specifies that a proxy can decide which future +versions of the GNU General Public License can be used, that proxy's +public statement of acceptance of a version permanently authorizes you +to choose that version for the Program. + + Later license versions may give you additional or different +permissions. However, no additional obligations are imposed on any +author or copyright holder as a result of your choosing to follow a +later version. + + 15. Disclaimer of Warranty. + + THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY +APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT +HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY +OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, +THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM +IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF +ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + + 16. Limitation of Liability. + + IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS +THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY +GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE +USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF +DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD +PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), +EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF +SUCH DAMAGES. + + 17. Interpretation of Sections 15 and 16. + + If the disclaimer of warranty and limitation of liability provided +above cannot be given local legal effect according to their terms, +reviewing courts shall apply local law that most closely approximates +an absolute waiver of all civil liability in connection with the +Program, unless a warranty or assumption of liability accompanies a +copy of the Program in return for a fee. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + <one line to give the program's name and a brief idea of what it does.> + Copyright (C) <year> <name of author> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + <program> Copyright (C) <year> <name of author> + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +<https://www.gnu.org/licenses/>. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +<https://www.gnu.org/licenses/why-not-lgpl.html>. |