46 lines
1.2 KiB
Rust
46 lines
1.2 KiB
Rust
export as_prec;
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export unop_prec;
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export token_to_binop;
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use token::*;
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use token::token;
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use ast::*;
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/// Unary operators have higher precedence than binary
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const unop_prec: uint = 100u;
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/**
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* Precedence of the `as` operator, which is a binary operator
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* but is not represented in the precedence table.
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*/
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const as_prec: uint = 11u;
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/**
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* Maps a token to a record specifying the corresponding binary
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* operator and its precedence
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*/
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fn token_to_binop(tok: token) -> Option<ast::binop> {
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match tok {
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BINOP(STAR) => Some(mul),
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BINOP(SLASH) => Some(div),
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BINOP(PERCENT) => Some(rem),
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// 'as' sits between here with 11
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BINOP(PLUS) => Some(add),
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BINOP(MINUS) => Some(subtract),
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BINOP(SHL) => Some(shl),
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BINOP(SHR) => Some(shr),
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BINOP(AND) => Some(bitand),
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BINOP(CARET) => Some(bitxor),
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BINOP(OR) => Some(bitor),
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LT => Some(lt),
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LE => Some(le),
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GE => Some(ge),
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GT => Some(gt),
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EQEQ => Some(eq),
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NE => Some(ne),
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ANDAND => Some(and),
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OROR => Some(or),
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_ => None
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}
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}
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