python_ast/ast/tree/
try_stmt.rs

1use proc_macro2::TokenStream;
2use pyo3::{Bound, FromPyObject, PyAny, PyResult, prelude::PyAnyMethods};
3use quote::quote;
4use serde::{Deserialize, Serialize};
5
6use crate::{
7    CodeGen, CodeGenContext, ExprType, Node, PythonOptions, Statement, SymbolTableScopes,
8    extract_list,
9};
10
11/// Try statement (try/except/else/finally)
12#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
13pub struct Try {
14    /// The main body of the try block
15    pub body: Vec<Statement>,
16    /// Exception handlers (except clauses)
17    pub handlers: Vec<ExceptHandler>,
18    /// Optional else clause body (executed when no exception occurs)
19    pub orelse: Vec<Statement>,
20    /// Optional finally clause body (always executed)
21    pub finalbody: Vec<Statement>,
22    /// Position information
23    pub lineno: Option<usize>,
24    pub col_offset: Option<usize>,
25    pub end_lineno: Option<usize>,
26    pub end_col_offset: Option<usize>,
27}
28
29/// Exception handler (except clause)
30#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
31pub struct ExceptHandler {
32    /// The exception type to catch (None means catch all)
33    pub exception_type: Option<ExprType>,
34    /// Variable name to bind the exception to (optional)
35    pub name: Option<String>,
36    /// Body of the except clause
37    pub body: Vec<Statement>,
38    /// Position information
39    pub lineno: Option<usize>,
40    pub col_offset: Option<usize>,
41    pub end_lineno: Option<usize>,
42    pub end_col_offset: Option<usize>,
43}
44
45impl<'a> FromPyObject<'a> for Try {
46    fn extract_bound(ob: &Bound<'a, PyAny>) -> PyResult<Self> {
47        // Extract body
48        let body: Vec<Statement> = extract_list(ob, "body", "try body")?;
49        
50        // Extract handlers
51        let handlers: Vec<ExceptHandler> = extract_list(ob, "handlers", "try handlers")?;
52        
53        // Extract orelse (optional)
54        let orelse: Vec<Statement> = extract_list(ob, "orelse", "try orelse").unwrap_or_default();
55        
56        // Extract finalbody (optional)
57        let finalbody: Vec<Statement> = extract_list(ob, "finalbody", "try finalbody").unwrap_or_default();
58        
59        Ok(Try {
60            body, 
61            handlers,
62            orelse,
63            finalbody,
64            lineno: ob.lineno(),
65            col_offset: ob.col_offset(),
66            end_lineno: ob.end_lineno(),
67            end_col_offset: ob.end_col_offset(),
68        })
69    }
70}
71
72impl<'a> FromPyObject<'a> for ExceptHandler {
73    fn extract_bound(ob: &Bound<'a, PyAny>) -> PyResult<Self> {
74        // Extract exception type (optional)
75        let exception_type: Option<ExprType> = if let Ok(type_attr) = ob.getattr("type") {
76            if type_attr.is_none() {
77                None
78            } else {
79                Some(type_attr.extract()?)
80            }
81        } else {
82            None
83        };
84        
85        // Extract name (optional)
86        let name: Option<String> = if let Ok(name_attr) = ob.getattr("name") {
87            if name_attr.is_none() {
88                None
89            } else {
90                Some(name_attr.extract()?)
91            }
92        } else {
93            None
94        };
95        
96        // Extract body
97        let body: Vec<Statement> = extract_list(ob, "body", "except handler body")?;
98        
99        Ok(ExceptHandler {
100            exception_type,
101            name,
102            body,
103            lineno: ob.lineno(),
104            col_offset: ob.col_offset(),
105            end_lineno: ob.end_lineno(),
106            end_col_offset: ob.end_col_offset(),
107        })
108    }
109}
110
111impl Node for Try {
112    fn lineno(&self) -> Option<usize> { self.lineno }
113    fn col_offset(&self) -> Option<usize> { self.col_offset }
114    fn end_lineno(&self) -> Option<usize> { self.end_lineno }
115    fn end_col_offset(&self) -> Option<usize> { self.end_col_offset }
116}
117
118impl Node for ExceptHandler {
119    fn lineno(&self) -> Option<usize> { self.lineno }
120    fn col_offset(&self) -> Option<usize> { self.col_offset }
121    fn end_lineno(&self) -> Option<usize> { self.end_lineno }
122    fn end_col_offset(&self) -> Option<usize> { self.end_col_offset }
123}
124
125impl CodeGen for Try {
126    type Context = CodeGenContext;
127    type Options = PythonOptions;
128    type SymbolTable = SymbolTableScopes;
129
130    fn find_symbols(self, symbols: Self::SymbolTable) -> Self::SymbolTable {
131        // Process body, handlers, orelse, and finalbody
132        let symbols = self.body.into_iter().fold(symbols, |acc, stmt| stmt.find_symbols(acc));
133        let symbols = self.handlers.into_iter().fold(symbols, |acc, handler| {
134            let symbols = handler.body.into_iter().fold(acc, |acc, stmt| stmt.find_symbols(acc));
135            if let Some(exception_type) = handler.exception_type {
136                exception_type.find_symbols(symbols)
137            } else {
138                symbols
139            }
140        });
141        let symbols = self.orelse.into_iter().fold(symbols, |acc, stmt| stmt.find_symbols(acc));
142        self.finalbody.into_iter().fold(symbols, |acc, stmt| stmt.find_symbols(acc))
143    }
144
145    fn to_rust(
146        self,
147        ctx: Self::Context,
148        options: Self::Options,
149        symbols: Self::SymbolTable,
150    ) -> Result<TokenStream, Box<dyn std::error::Error>> {
151        // Generate the try body
152        let try_body_tokens: Result<Vec<TokenStream>, Box<dyn std::error::Error>> = self.body.into_iter()
153            .map(|stmt| stmt.to_rust(ctx.clone(), options.clone(), symbols.clone()))
154            .collect();
155        let try_body_tokens = try_body_tokens?;
156
157        // Generate catch blocks for each handler
158        let catch_blocks: Result<Vec<TokenStream>, Box<dyn std::error::Error>> = self.handlers.into_iter()
159            .map(|handler| {
160                let handler_body_tokens: Result<Vec<TokenStream>, Box<dyn std::error::Error>> = handler.body.into_iter()
161                    .map(|stmt| stmt.to_rust(ctx.clone(), options.clone(), symbols.clone()))
162                    .collect();
163                let handler_body_tokens = handler_body_tokens?;
164
165                // For now, generate a generic catch block
166                // In a real implementation, you'd want to match specific exception types
167                Ok::<TokenStream, Box<dyn std::error::Error>>(quote! {
168                    // Exception handler - simplified translation
169                    #(#handler_body_tokens)*
170                })
171            })
172            .collect();
173        let catch_blocks = catch_blocks?;
174
175        // Generate else clause if present
176        let else_tokens = if !self.orelse.is_empty() {
177            let else_body_tokens: Result<Vec<TokenStream>, Box<dyn std::error::Error>> = self.orelse.into_iter()
178                .map(|stmt| stmt.to_rust(ctx.clone(), options.clone(), symbols.clone()))
179                .collect();
180            let else_body_tokens = else_body_tokens?;
181            quote! {
182                // Else clause (executed when no exception occurs)
183                #(#else_body_tokens)*
184            }
185        } else {
186            quote!()
187        };
188
189        // Generate finally clause if present
190        let finally_tokens = if !self.finalbody.is_empty() {
191            let finally_body_tokens: Result<Vec<TokenStream>, Box<dyn std::error::Error>> = self.finalbody.into_iter()
192                .map(|stmt| stmt.to_rust(ctx.clone(), options.clone(), symbols.clone()))
193                .collect();
194            let finally_body_tokens = finally_body_tokens?;
195            quote! {
196                // Finally clause (always executed)
197                #(#finally_body_tokens)*
198            }
199        } else {
200            quote!()
201        };
202
203        // Generate a simplified try-catch structure
204        // Note: This is a basic translation - Rust's error handling is quite different from Python's
205        Ok(quote! {
206            {
207                // Try block - simplified translation to Rust
208                // Python's exception handling doesn't map directly to Rust's Result/Option patterns
209                #(#try_body_tokens)*
210                
211                // Catch blocks (simplified)
212                #(#catch_blocks)*
213                
214                // Else clause
215                #else_tokens
216                
217                // Finally clause  
218                #finally_tokens
219            }
220        })
221    }
222}
223
224#[cfg(test)]
225mod tests {
226    // Tests would go here - currently commented out as they need full AST infrastructure
227    // create_parse_test!(test_simple_try, "try:\n    pass\nexcept:\n    pass", "test.py");
228}
python_ast/ast/tree/try_stmt.rs

python_ast/ast/tree/
try_stmt.rs
