84 lines
1.6 KiB
Text
84 lines
1.6 KiB
Text
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import "../option";
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import "../numbers";
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import "../vec";
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import "../string";
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import "../io";
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mod Bolt::Lang {
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pub struct Pos {
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offset: usize,
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line: usize,
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column: usize,
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}
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pub struct Span {
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file: IO::File,
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start: Pos,
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end: Pos,
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}
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define_nodes! {
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Identifier : Symbol {
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text: String,
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},
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Statement,
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ReturnStatement : Statement {
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expression: Option<Expression>,
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},
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ConditionalCase {
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test: Option<Expression>,
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result: Vec<FunctionBodyElement>,
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},
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ConditionalStatement : Statement {
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cases: Vec<ConditionalCase>,
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},
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Expression,
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ReferenceExpression : Expression {
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modulePath: Option<ModulePath>,
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name: Symbol,
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}
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}
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pub type Transformer = fn (node: Node) -> Node;
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fn build_predicate_from_pattern(pattern: Pattern) -> Expression {
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match pattern {
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BindPattern { name } => quote(true).taint(pattern),
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VariantPatten { elements } => quote(or($(elements),*)),
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RecordPattern { members } => quote(and($elements),*)),
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}
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}
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fn eliminate_match_rule(node: Node) {
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match node {
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quote {
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match $value: Expression {
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$patterns @ ( $pattern: Pattern => $expression: Expression ),* (,)?
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}
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} => {
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let cases = patterns.map(|pattern| {
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ConditionalCase::from_node(
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pattern,
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build_predicate_from_pattern(pattern),
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value
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)
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});
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return ConditionalStatement::from_node(node, cases);
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}
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}
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}
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register_transformer!(elminate_match_rule);
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}
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