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rhs production

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greg 2015-07-24 02:23:18 -07:00
parent a97cce184c
commit 05238bced3
1 changed files with 21 additions and 14 deletions
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35
src/parser.rs
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@ -104,20 +104,10 @@ fn let_expression(input: &mut Tokens) -> ParseResult {
if let Some(&Identifier(ref name)) = input.next() { if let Some(&Identifier(ref name)) = input.next() {
if let Some(&Identifier(ref s)) = input.next() { if let Some(&Identifier(ref s)) = input.next() {
if s == "=" { if s == "=" {
let next = input.next(); if let ParseResult::Ok(rhs) = rhs(input) {
if let Some(&Identifier(ref value)) = next { return ParseResult::Ok(
let ast = AST::Binding(name.clone(), Box::new(AST::Name(value.clone()))); AST::Binding(name.clone(),
return ParseResult::Ok(ast); Box::new(rhs)));
}
if let Some(&StrLiteral(ref value)) = next {
let ast = AST::Binding(name.clone(), Box::new(AST::LangString(value.clone())));
return ParseResult::Ok(ast);
}
if let Some(&NumLiteral(n)) = next {
let ast = AST::Binding(name.clone(), Box::new(AST::Number(n)));
return ParseResult::Ok(ast);
} }
} }
} }
@ -125,3 +115,20 @@ fn let_expression(input: &mut Tokens) -> ParseResult {
return ParseResult::Err("Bad parse in let_expression()".to_string()); return ParseResult::Err("Bad parse in let_expression()".to_string());
} }
fn rhs(input: &mut Tokens) -> ParseResult {
let next = input.next();
if let Some(&Identifier(ref value)) = next {
return ParseResult::Ok(AST::Name(value.clone()));
}
if let Some(&StrLiteral(ref value)) = next {
return ParseResult::Ok(AST::LangString(value.clone()));
}
if let Some(&NumLiteral(n)) = next {
return ParseResult::Ok(AST::Number(n));
}
return ParseResult::Err("Bad parse in rhs()".to_string());
}