RustPython-Parser/parser/src/parser.rs
harupy f260785da4 Remove useless String::from
Signed-off-by: harupy <hkawamura0130@gmail.com>
2023-01-16 21:27:57 +09:00

312 lines
9 KiB
Rust

//! Python parsing.
//!
//! Use this module to parse python code into an AST.
//! There are three ways to parse python code. You could
//! parse a whole program, a single statement, or a single
//! expression.
use crate::lexer::{LexResult, Tok};
pub use crate::mode::Mode;
use crate::{ast, error::ParseError, lexer, python};
use ast::Location;
use itertools::Itertools;
use std::iter;
/*
* Parse python code.
* Grammar may be inspired by antlr grammar for python:
* https://github.com/antlr/grammars-v4/tree/master/python3
*/
/// Parse a full python program, containing usually multiple lines.
pub fn parse_program(source: &str, source_path: &str) -> Result<ast::Suite, ParseError> {
parse(source, Mode::Module, source_path).map(|top| match top {
ast::Mod::Module { body, .. } => body,
_ => unreachable!(),
})
}
/// Parses a python expression
///
/// # Example
/// ```
/// extern crate num_bigint;
/// use rustpython_parser::{parser, ast};
/// let expr = parser::parse_expression("1 + 2", "<embedded>").unwrap();
///
/// assert_eq!(
/// expr,
/// ast::Expr {
/// location: ast::Location::new(1, 0),
/// end_location: Some(ast::Location::new(1, 5)),
/// custom: (),
/// node: ast::ExprKind::BinOp {
/// left: Box::new(ast::Expr {
/// location: ast::Location::new(1, 0),
/// end_location: Some(ast::Location::new(1, 1)),
/// custom: (),
/// node: ast::ExprKind::Constant {
/// value: ast::Constant::Int(1.into()),
/// kind: None,
/// }
/// }),
/// op: ast::Operator::Add,
/// right: Box::new(ast::Expr {
/// location: ast::Location::new(1, 4),
/// end_location: Some(ast::Location::new(1, 5)),
/// custom: (),
/// node: ast::ExprKind::Constant {
/// value: ast::Constant::Int(2.into()),
/// kind: None,
/// }
/// })
/// }
/// },
/// );
///
/// ```
pub fn parse_expression(source: &str, path: &str) -> Result<ast::Expr, ParseError> {
parse_expression_located(source, path, Location::new(1, 0))
}
pub fn parse_expression_located(
source: &str,
path: &str,
location: Location,
) -> Result<ast::Expr, ParseError> {
parse_located(source, Mode::Expression, path, location).map(|top| match top {
ast::Mod::Expression { body } => *body,
_ => unreachable!(),
})
}
// Parse a given source code
pub fn parse(source: &str, mode: Mode, source_path: &str) -> Result<ast::Mod, ParseError> {
parse_located(source, mode, source_path, Location::new(1, 0))
}
// Parse a given source code from a given location
pub fn parse_located(
source: &str,
mode: Mode,
source_path: &str,
location: Location,
) -> Result<ast::Mod, ParseError> {
let lxr = lexer::make_tokenizer_located(source, location);
parse_tokens(lxr, mode, source_path)
}
// Parse a given token iterator.
pub fn parse_tokens(
lxr: impl IntoIterator<Item = LexResult>,
mode: Mode,
source_path: &str,
) -> Result<ast::Mod, ParseError> {
let marker_token = (Default::default(), mode.to_marker(), Default::default());
let tokenizer = iter::once(Ok(marker_token))
.chain(lxr)
.filter_ok(|(_, tok, _)| !matches!(tok, Tok::Comment { .. } | Tok::NonLogicalNewline));
python::TopParser::new()
.parse(tokenizer)
.map_err(|e| crate::error::parse_error_from_lalrpop(e, source_path))
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_parse_empty() {
let parse_ast = parse_program("", "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_string() {
let source = "'Hello world'";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_f_string() {
let source = "f'Hello world'";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_print_hello() {
let source = "print('Hello world')";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_print_2() {
let source = "print('Hello world', 2)";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_kwargs() {
let source = "my_func('positional', keyword=2)";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_if_elif_else() {
let source = "if 1: 10\nelif 2: 20\nelse: 30";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_lambda() {
let source = "lambda x, y: x * y"; // lambda(x, y): x * y";
let parse_ast = parse_program(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_tuples() {
let source = "a, b = 4, 5";
insta::assert_debug_snapshot!(parse_program(source, "<test>").unwrap());
}
#[test]
fn test_parse_class() {
let source = "\
class Foo(A, B):
def __init__(self):
pass
def method_with_default(self, arg='default'):
pass
";
insta::assert_debug_snapshot!(parse_program(source, "<test>").unwrap());
}
#[test]
fn test_parse_dict_comprehension() {
let source = "{x1: x2 for y in z}";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_list_comprehension() {
let source = "[x for y in z]";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_double_list_comprehension() {
let source = "[x for y, y2 in z for a in b if a < 5 if a > 10]";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_generator_comprehension() {
let source = "(x for y in z)";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_named_expression_generator_comprehension() {
let source = "(x := y + 1 for y in z)";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_if_else_generator_comprehension() {
let source = "(x if y else y for y in z)";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_boolop_or() {
let source = "x or y";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_parse_boolop_and() {
let source = "x and y";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_slice() {
let source = "x[1:2:3]";
let parse_ast = parse_expression(source, "<test>").unwrap();
insta::assert_debug_snapshot!(parse_ast);
}
#[test]
fn test_with_statement() {
let source = "\
with 0: pass
with 0 as x: pass
with 0, 1: pass
with 0 as x, 1 as y: pass
with 0 if 1 else 2: pass
with 0 if 1 else 2 as x: pass
with (): pass
with () as x: pass
with (0): pass
with (0) as x: pass
with (0,): pass
with (0,) as x: pass
with (0, 1): pass
with (0, 1) as x: pass
with (*a,): pass
with (*a,) as x: pass
with (0, *a): pass
with (0, *a) as x: pass
with (a := 0): pass
with (a := 0) as x: pass
with (a := 0, b := 1): pass
with (a := 0, b := 1) as x: pass
with (0 as a): pass
with (0 as a,): pass
with (0 as a, 1 as b): pass
with (0 as a, 1 as b,): pass
";
insta::assert_debug_snapshot!(parse_program(source, "<test>").unwrap());
}
#[test]
fn test_with_statement_invalid() {
for source in [
"with 0,: pass",
"with 0 as x,: pass",
"with 0 as *x: pass",
"with *a: pass",
"with *a as x: pass",
"with (*a): pass",
"with (*a) as x: pass",
"with *a, 0 as x: pass",
"with (*a, 0 as x): pass",
"with 0 as x, *a: pass",
"with (0 as x, *a): pass",
"with (0 as x) as y: pass",
"with (0 as x), 1: pass",
"with ((0 as x)): pass",
"with a := 0 as x: pass",
"with (a := 0 as x): pass",
] {
assert!(parse_program(source, "<test>").is_err());
}
}
}