shannon_brush_parser/
test_command.rs

1//! Parser for shell test commands.
2
3use crate::{ast, error};
4
5/// Parses a test command expression.
6///
7/// # Arguments
8///
9/// * `input` - The test command expression to parse, in string form.
10pub fn parse<S: AsRef<str>>(input: &[S]) -> Result<ast::TestExpr, error::TestCommandParseError> {
11    let expr =
12        test_command::full_expression(&input.iter().map(AsRef::as_ref).collect::<Vec<&str>>())?;
13
14    Ok(expr)
15}
16
17peg::parser! {
18    grammar test_command<'a>() for [&'a str] {
19        pub(crate) rule full_expression() -> ast::TestExpr =
20            end() { ast::TestExpr::False } /
21            e:one_arg_expr() end() { e } /
22            e:two_arg_expr() end()  { e } /
23            e:three_arg_expr() end()  { e } /
24            e:four_arg_expr() end()  { e } /
25            expression()
26
27        rule one_arg_expr() -> ast::TestExpr =
28            [s] { ast::TestExpr::Literal(s.to_owned()) }
29
30        rule two_arg_expr() -> ast::TestExpr =
31            ["!"] e:one_arg_expr() { ast::TestExpr::Not(Box::from(e)) } /
32            op:unary_op() [s] { ast::TestExpr::UnaryTest(op, s.to_owned()) }
33
34        rule three_arg_expr() -> ast::TestExpr =
35            [left] ["-a"] [right] { ast::TestExpr::And(Box::from(ast::TestExpr::Literal(left.to_owned())), Box::from(ast::TestExpr::Literal(right.to_owned()))) } /
36            [left] ["-o"] [right] { ast::TestExpr::Or(Box::from(ast::TestExpr::Literal(left.to_owned())), Box::from(ast::TestExpr::Literal(right.to_owned()))) } /
37            [left] op:binary_op() [right] { ast::TestExpr::BinaryTest(op, left.to_owned(), right.to_owned()) } /
38            ["!"] e:two_arg_expr() { ast::TestExpr::Not(Box::from(e)) } /
39            ["("] e:one_arg_expr() [")"] { e }
40
41        rule four_arg_expr() -> ast::TestExpr =
42            ["!"] e:three_arg_expr() { ast::TestExpr::Not(Box::from(e)) }
43
44        rule expression() -> ast::TestExpr = precedence! {
45            left:(@) ["-a"] right:@ { ast::TestExpr::And(Box::from(left), Box::from(right)) }
46            left:(@) ["-o"] right:@ { ast::TestExpr::Or(Box::from(left), Box::from(right)) }
47            --
48            ["("] e:expression() [")"] { ast::TestExpr::Parenthesized(Box::from(e)) }
49            --
50            ["!"] e:@ { ast::TestExpr::Not(Box::from(e)) }
51            --
52            [left] op:binary_op() [right] { ast::TestExpr::BinaryTest(op, left.to_owned(), right.to_owned()) }
53            --
54            op:unary_op() [operand] { ast::TestExpr::UnaryTest(op, operand.to_owned()) }
55            --
56            [s] { ast::TestExpr::Literal(s.to_owned()) }
57        }
58
59        rule unary_op() -> ast::UnaryPredicate =
60            ["-a"] { ast::UnaryPredicate::FileExists } /
61            ["-b"] { ast::UnaryPredicate::FileExistsAndIsBlockSpecialFile } /
62            ["-c"] { ast::UnaryPredicate::FileExistsAndIsCharSpecialFile } /
63            ["-d"] { ast::UnaryPredicate::FileExistsAndIsDir } /
64            ["-e"] { ast::UnaryPredicate::FileExists } /
65            ["-f"] { ast::UnaryPredicate::FileExistsAndIsRegularFile } /
66            ["-g"] { ast::UnaryPredicate::FileExistsAndIsSetgid } /
67            ["-h"] { ast::UnaryPredicate::FileExistsAndIsSymlink } /
68            ["-k"] { ast::UnaryPredicate::FileExistsAndHasStickyBit } /
69            ["-n"] { ast::UnaryPredicate::StringHasNonZeroLength } /
70            ["-o"] { ast::UnaryPredicate::ShellOptionEnabled } /
71            ["-p"] { ast::UnaryPredicate::FileExistsAndIsFifo } /
72            ["-r"] { ast::UnaryPredicate::FileExistsAndIsReadable } /
73            ["-s"] { ast::UnaryPredicate::FileExistsAndIsNotZeroLength } /
74            ["-t"] { ast::UnaryPredicate::FdIsOpenTerminal } /
75            ["-u"] { ast::UnaryPredicate::FileExistsAndIsSetuid } /
76            ["-v"] { ast::UnaryPredicate::ShellVariableIsSetAndAssigned } /
77            ["-w"] { ast::UnaryPredicate::FileExistsAndIsWritable } /
78            ["-x"] { ast::UnaryPredicate::FileExistsAndIsExecutable } /
79            ["-z"] { ast::UnaryPredicate::StringHasZeroLength } /
80            ["-G"] { ast::UnaryPredicate::FileExistsAndOwnedByEffectiveGroupId } /
81            ["-L"] { ast::UnaryPredicate::FileExistsAndIsSymlink } /
82            ["-N"] { ast::UnaryPredicate::FileExistsAndModifiedSinceLastRead } /
83            ["-O"] { ast::UnaryPredicate::FileExistsAndOwnedByEffectiveUserId } /
84            ["-R"] { ast::UnaryPredicate::ShellVariableIsSetAndNameRef } /
85            ["-S"] { ast::UnaryPredicate::FileExistsAndIsSocket }
86
87        rule binary_op() -> ast::BinaryPredicate =
88            ["=="]  { ast::BinaryPredicate::StringExactlyMatchesString } /
89            ["-ef"] { ast::BinaryPredicate::FilesReferToSameDeviceAndInodeNumbers } /
90            ["-eq"] { ast::BinaryPredicate::ArithmeticEqualTo } /
91            ["-ge"] { ast::BinaryPredicate::ArithmeticGreaterThanOrEqualTo } /
92            ["-gt"] { ast::BinaryPredicate::ArithmeticGreaterThan } /
93            ["-le"] { ast::BinaryPredicate::ArithmeticLessThanOrEqualTo } /
94            ["-lt"] { ast::BinaryPredicate::ArithmeticLessThan } /
95            ["-ne"] { ast::BinaryPredicate::ArithmeticNotEqualTo } /
96            ["-nt"] { ast::BinaryPredicate::LeftFileIsNewerOrExistsWhenRightDoesNot } /
97            ["-ot"] { ast::BinaryPredicate::LeftFileIsOlderOrDoesNotExistWhenRightDoes } /
98            ["="]   { ast::BinaryPredicate::StringExactlyMatchesString } /
99            ["!="]  { ast::BinaryPredicate::StringDoesNotExactlyMatchString } /
100            ["<"]   { ast::BinaryPredicate::LeftSortsBeforeRight } /
101            [">"]   { ast::BinaryPredicate::LeftSortsAfterRight }
102
103        rule end() = ![_]
104    }
105}
shannon_brush_parser/test_command.rs

shannon_brush_parser/
test_command.rs
