python_ast/ast/tree/
while_stmt.rs

1use proc_macro2::TokenStream;
2use pyo3::{Bound, FromPyObject, PyAny, PyResult, types::PyAnyMethods};
3use quote::quote;
4use serde::{Deserialize, Serialize};
5
6use crate::{
7    CodeGen, CodeGenContext, ExprType, PythonOptions, SymbolTableScopes,
8    Node, impl_node_with_positions, PyAttributeExtractor, extract_list
9};
10
11use super::Statement;
12
13#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
14pub struct While {
15    pub test: ExprType,
16    pub body: Vec<Statement>,
17    pub orelse: Vec<Statement>,
18    pub lineno: Option<usize>,
19    pub col_offset: Option<usize>,
20    pub end_lineno: Option<usize>,
21    pub end_col_offset: Option<usize>,
22}
23
24impl<'a> FromPyObject<'a> for While {
25    fn extract_bound(ob: &Bound<'a, PyAny>) -> PyResult<Self> {
26        let test = ob.extract_attr_with_context("test", "while test condition")?;
27        let test = test.extract().expect("getting while test");
28        
29        let body: Vec<Statement> = extract_list(ob, "body", "while body statements")?;
30        let orelse: Vec<Statement> = extract_list(ob, "orelse", "while else statements")?;
31        
32        Ok(While {
33            test,
34            body,
35            orelse,
36            lineno: ob.lineno(),
37            col_offset: ob.col_offset(),
38            end_lineno: ob.end_lineno(),
39            end_col_offset: ob.end_col_offset(),
40        })
41    }
42}
43
44impl_node_with_positions!(While { lineno, col_offset, end_lineno, end_col_offset });
45
46impl CodeGen for While {
47    type Context = CodeGenContext;
48    type Options = PythonOptions;
49    type SymbolTable = SymbolTableScopes;
50
51    fn find_symbols(self, symbols: Self::SymbolTable) -> Self::SymbolTable {
52        let symbols = self.test.find_symbols(symbols);
53        let symbols = self.body.into_iter().fold(symbols, |acc, stmt| stmt.find_symbols(acc));
54        self.orelse.into_iter().fold(symbols, |acc, stmt| stmt.find_symbols(acc))
55    }
56
57    fn to_rust(
58        self,
59        ctx: Self::Context,
60        options: Self::Options,
61        symbols: Self::SymbolTable,
62    ) -> Result<TokenStream, Box<dyn std::error::Error>> {
63        let test = self.test.to_rust(ctx.clone(), options.clone(), symbols.clone())?;
64        
65        let body_stmts: Result<Vec<_>, _> = self.body
66            .into_iter()
67            .map(|stmt| stmt.to_rust(ctx.clone(), options.clone(), symbols.clone()))
68            .collect();
69        let body_stmts = body_stmts?;
70        
71        if self.orelse.is_empty() {
72            Ok(quote! {
73                while #test {
74                    #(#body_stmts)*
75                }
76            })
77        } else {
78            // Note: Rust doesn't have while-else, so we need to track completion
79            let else_stmts: Result<Vec<_>, _> = self.orelse
80                .into_iter()
81                .map(|stmt| stmt.to_rust(ctx.clone(), options.clone(), symbols.clone()))
82                .collect();
83            let else_stmts = else_stmts?;
84            
85            Ok(quote! {
86                {
87                    let mut broke = false;
88                    while #test {
89                        #(#body_stmts)*
90                    }
91                    if !broke {
92                        #(#else_stmts)*
93                    }
94                }
95            })
96        }
97    }
98}
99
100#[cfg(test)]
101mod tests {
102    use super::*;
103    use crate::create_parse_test;
104
105    create_parse_test!(test_simple_while, "while x > 0:\n    x -= 1", "while_test.py");
106    create_parse_test!(test_while_else, "while x > 0:\n    x -= 1\nelse:\n    print('done')", "while_test.py");
107    create_parse_test!(test_while_true, "while True:\n    break", "while_test.py");
108}
python_ast/ast/tree/while_stmt.rs

python_ast/ast/tree/
while_stmt.rs
