iframe-proxy | Sunbelt Computer Software

History

167 lines (147 loc) · 4.76 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

//! 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 std::iter;

use crate::ast;

use crate::error::ParseError;

use crate::lexer;

pub use crate::mode::Mode;

use crate::python;

* 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) -> Result<ast::Suite, ParseError> {

parse(source, Mode::Module).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").unwrap();

///

/// assert_eq!(

/// expr,

/// ast::Expr {

/// location: ast::Location::new(1, 3),

/// custom: (),

/// node: ast::ExprKind::BinOp {

/// left: Box::new(ast::Expr {

/// location: 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, 5),

/// custom: (),

/// node: ast::ExprKind::Constant {

/// value: ast::Constant::Int(2.into()),

/// kind: None,

/// }

/// })

/// }

/// },

/// );

///

/// ```

pub fn parse_expression(source: &str) -> Result<ast::Expr, ParseError> {

parse(source, Mode::Expression).map(|top| match top {

ast::Mod::Expression { body } => *body,

_ => unreachable!(),

})

}

// Parse a given source code

pub fn parse(source: &str, mode: Mode) -> Result<ast::Mod, ParseError> {

let lxr = lexer::make_tokenizer(source);

let marker_token = (Default::default(), mode.to_marker(), Default::default());

let tokenizer = iter::once(Ok(marker_token)).chain(lxr);

python::TopParser::new()

.parse(tokenizer)

.map_err(ParseError::from)

}

#[cfg(test)]

mod tests {

use super::*;

#[test]

fn test_parse_empty() {

let parse_ast = parse_program("").unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

#[test]

fn test_parse_print_hello() {

let source = String::from("print('Hello world')");

let parse_ast = parse_program(&source).unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

#[test]

fn test_parse_print_2() {

let source = String::from("print('Hello world', 2)");

let parse_ast = parse_program(&source).unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

#[test]

fn test_parse_kwargs() {

let source = String::from("my_func('positional', keyword=2)");

let parse_ast = parse_program(&source).unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

#[test]

fn test_parse_if_elif_else() {

let source = String::from("if 1: 10\nelif 2: 20\nelse: 30");

let parse_ast = parse_program(&source).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).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).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).unwrap());

}

#[test]

fn test_parse_dict_comprehension() {

let source = String::from("{x1: x2 for y in z}");

let parse_ast = parse_expression(&source).unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

#[test]

fn test_parse_list_comprehension() {

let source = String::from("[x for y in z]");

let parse_ast = parse_expression(&source).unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

#[test]

fn test_parse_double_list_comprehension() {

let source = String::from("[x for y, y2 in z for a in b if a < 5 if a > 10]");

let parse_ast = parse_expression(&source).unwrap();

insta::assert_debug_snapshot!(parse_ast);

}

Sunbelt Computer Software

PL/B Language Development and Support

Navigation Menu

Sunbelt Computer Software

PL/B Language Development and Support

FilesExpand file tree

parser.rs

Latest commit

History

parser.rs

File metadata and controls