trilogy-parser/src/syntax/assignment_statement.rs at string-repr-callable

Actually just three programming languages in a trenchcoat
trilogy / trilogy-parser / src / syntax / assignment_statement.rs
at string-repr-callable 201 lines 13 kB view raw
wrap content
  1use super::*;
  2use crate::{Parser, Spanned};
  3use source_span::Span;
  4use trilogy_scanner::{
  5    Token,
  6    TokenType::{self, *},
  7};
  8
  9/// An assignment statement. An assignment may have one of many "strategies".
 10///
 11/// [`FunctionAssignment`][] is parsed separately.
 12///
 13/// ```trilogy
 14/// lhs = rhs
 15/// ```
 16#[derive(Clone, Debug, PrettyPrintSExpr)]
 17pub struct AssignmentStatement {
 18    pub lhs: Expression,
 19    pub strategy: AssignmentStrategy,
 20    pub rhs: Expression,
 21    span: Span,
 22}
 23
 24impl Spanned for AssignmentStatement {
 25    fn span(&self) -> Span {
 26        self.span
 27    }
 28}
 29
 30impl AssignmentStatement {
 31    pub(crate) const ASSIGNMENT_OPERATOR: [TokenType; 24] = [
 32        OpEq,
 33        OpAmpAmpEq,
 34        OpPipePipeEq,
 35        OpAmpEq,
 36        OpPipeEq,
 37        OpCaretEq,
 38        OpShrEq,
 39        OpShlEq,
 40        OpShrExEq,
 41        OpShlExEq,
 42        OpShrConEq,
 43        OpShlConEq,
 44        OpGlueEq,
 45        OpPlusEq,
 46        OpMinusEq,
 47        OpStarEq,
 48        OpSlashEq,
 49        OpSlashSlashEq,
 50        OpPercentEq,
 51        OpStarStarEq,
 52        OpLtLtEq,
 53        OpGtGtEq,
 54        OpColonEq,
 55        OpDotEq,
 56    ];
 57
 58    pub(crate) fn parse(parser: &mut Parser, lhs: Expression) -> SyntaxResult<Self> {
 59        let strategy = AssignmentStrategy::parse(parser)?;
 60        let rhs = Expression::parse(parser)?;
 61        Ok(Self {
 62            span: lhs.span().union(rhs.span()),
 63            lhs,
 64            strategy,
 65            rhs,
 66        })
 67    }
 68}
 69
 70/// The strategy of an assignment statement.
 71#[derive(Clone, Debug, Spanned, PrettyPrintSExpr)]
 72pub enum AssignmentStrategy {
 73    Direct(Token),
 74    And(Token),
 75    Or(Token),
 76    Add(Token),
 77    Subtract(Token),
 78    Multiply(Token),
 79    Divide(Token),
 80    Remainder(Token),
 81    Power(Token),
 82    IntDivide(Token),
 83    BitwiseAnd(Token),
 84    BitwiseOr(Token),
 85    BitwiseXor(Token),
 86    LeftShift(Token),
 87    RightShift(Token),
 88    LeftShiftExtend(Token),
 89    RightShiftExtend(Token),
 90    LeftShiftContract(Token),
 91    RightShiftContract(Token),
 92    Glue(Token),
 93    Compose(Token),
 94    RCompose(Token),
 95    Access(Token),
 96    Cons(Token),
 97}
 98
 99impl AssignmentStrategy {
100    fn parse(parser: &mut Parser) -> SyntaxResult<Self> {
101        let token = parser
102            .expect(AssignmentStatement::ASSIGNMENT_OPERATOR)
103            .map_err(|token| {
104                parser.expected(token, "expected assignment operator (ending with `=`)")
105            })?;
106        Ok(match token.token_type {
107            OpEq => Self::Direct(token),
108            OpAmpAmpEq => Self::And(token),
109            OpPipePipeEq => Self::Or(token),
110            OpAmpEq => Self::BitwiseAnd(token),
111            OpPipeEq => Self::BitwiseOr(token),
112            OpCaretEq => Self::BitwiseXor(token),
113            OpShlEq => Self::LeftShift(token),
114            OpShrEq => Self::RightShift(token),
115            OpShlExEq => Self::LeftShiftExtend(token),
116            OpShrExEq => Self::RightShiftExtend(token),
117            OpShlConEq => Self::LeftShiftContract(token),
118            OpShrConEq => Self::RightShiftContract(token),
119            OpGlueEq => Self::Glue(token),
120            OpPlusEq => Self::Add(token),
121            OpMinusEq => Self::Subtract(token),
122            OpStarEq => Self::Multiply(token),
123            OpSlashEq => Self::Divide(token),
124            OpSlashSlashEq => Self::IntDivide(token),
125            OpPercentEq => Self::Remainder(token),
126            OpStarStarEq => Self::Power(token),
127            OpLtLtEq => Self::RCompose(token),
128            OpGtGtEq => Self::Compose(token),
129            OpColonEq => Self::Cons(token),
130            OpDotEq => Self::Access(token),
131            _ => unreachable!(),
132        })
133    }
134}
135
136#[cfg(test)]
137mod test {
138    use super::*;
139
140    test_parse!(assignment_direct: "x = 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
141    test_parse!(assignment_and: "x &&= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::And _) _))");
142    test_parse!(assignment_or: "x ||= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Or _) _))");
143    test_parse!(assignment_add: "x += 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Add _) _))");
144    test_parse!(assignment_subtract: "x -= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Subtract _) _))");
145    test_parse!(assignment_multiply: "x *= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Multiply _) _))");
146    test_parse!(assignment_divide: "x /= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Divide _) _))");
147    test_parse!(assignment_remainder: "x %= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Remainder _) _))");
148    test_parse!(assignment_power: "x **= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Power _) _))");
149    test_parse!(assignment_int_divide: "x //= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::IntDivide _) _))");
150    test_parse!(assignment_bitwise_and: "x &= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::BitwiseAnd _) _))");
151    test_parse!(assignment_bitwise_or: "x |= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::BitwiseOr _) _))");
152    test_parse!(assignment_bitwise_xor: "x ^= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::BitwiseXor _) _))");
153    test_parse!(assignment_left_shift: "x <~= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::LeftShift _) _))");
154    test_parse!(assignment_right_shift: "x ~>= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::RightShift _) _))");
155    test_parse!(assignment_left_shift_ex: "x <~~= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::LeftShiftExtend _) _))");
156    test_parse!(assignment_right_shift_ex: "x ~~>= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::RightShiftExtend _) _))");
157    test_parse!(assignment_left_shift_con: "x <<~= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::LeftShiftContract _) _))");
158    test_parse!(assignment_right_shift_con: "x ~>>= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::RightShiftContract _) _))");
159    test_parse!(assignment_glue: "x <>= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Glue _) _))");
160    test_parse!(assignment_compose: "x >>= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Compose _) _))");
161    test_parse!(assignment_rcompose: "x <<= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::RCompose _) _))");
162    test_parse!(assignment_access: "x .= 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Access _) _))");
163    test_parse!(assignment_cons: "x := 5" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Cons _) _))");
164
165    test_parse_error!(assignment_not_fn: "a x = 7" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
166    test_parse_error!(assignment_not_proc: "a!() = 7" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
167    test_parse_error!(assignment_contains_not: "[a, a!()] = 7" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
168
169    test_parse!(assignment_left_access: "a.b = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
170    test_parse!(assignment_proc_but_access: "a!().x = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
171    test_parse!(assignment_left_array: "[a, b, c] = [1, 2, 3]" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
172    test_parse!(assignment_left_array_spread_start: "[..a, b, c] = []" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
173    test_parse!(assignment_left_array_spread_middle: "[a, ..b, c] = []" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
174    test_parse!(assignment_left_array_spread_end: "[a, b, ..c] = []" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
175    test_parse_error!(assignment_left_array_spread_multi: "[..a, b, ..c] = []" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
176    test_parse!(assignment_left_record: "{| \"a\" => a |} = {||}" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
177    test_parse!(assignment_left_record_spread: "{| \"a\" => b, ..c |} = {||}" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
178    test_parse_error!(assignment_left_record_spread_not_last: "{| ..c, \"a\" => b |} = {||}" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
179    test_parse_error!(assignment_left_record_spread_multi: "{| ..a, ..c |} = {||}" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
180    test_parse!(assignment_left_set: "[| a, b |] = [||]" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
181    test_parse!(assignment_left_set_spread: "[| \"a\", ..c |] = [||]" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
182    test_parse_error!(assignment_left_set_spread_not_last: "[| ..c, \"a\" |] = [||]" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
183    test_parse_error!(assignment_left_set_spread_multi: "[| ..a, ..c |] = [||]" => Statement::parse => "cannot assign to an expression that is not a valid assignment target");
184    test_parse!(assignment_left_glue: "\"hello \" <> world = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
185    test_parse!(assignment_left_neg: "-world = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
186    test_parse!(assignment_left_cons: "hello : world = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
187    test_parse!(assignment_left_struct: "'hello(x) = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
188    test_parse!(assignment_left_paren: "(x) = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
189    test_parse!(assignment_left_lit_false: "false = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
190    test_parse!(assignment_left_lit_true: "true = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
191    test_parse!(assignment_left_lit_unit: "unit = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
192    test_parse!(assignment_left_lit_atom: "'atom = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
193    test_parse!(assignment_left_lit_num: "7 = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
194    test_parse!(assignment_left_lit_char: "'7' = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
195    test_parse!(assignment_left_lit_str: "\"7\" = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
196    test_parse!(assignment_left_lit_bits: "0bb0101 = 7" => Statement::parse => "(Statement::Assignment (AssignmentStatement _ (AssignmentStrategy::Direct _) _))");
197
198    test_parse_error!(assignment_left_block: "{ call!() } = 7" => Statement::parse);
199    test_parse_error!(assignment_left_block_empty: "{} = 7" => Statement::parse);
200    test_parse_error!(assignment_left_record_no_paren: "{ x => y } = 7" => Statement::parse);
201}