26 lines
669 B
Rust
26 lines
669 B
Rust
use parser::AST;
|
|
use parser::AST::*;
|
|
|
|
pub fn evaluate(ast: AST) -> String {
|
|
match reduce(ast) {
|
|
None => return "error".to_string(),
|
|
Some(DoNothing) => "".to_string(),
|
|
Some(Number(n)) => return format!("{}", n),
|
|
Some(LangString(s)) => return format!("\"{}\"", s),
|
|
_ => return "not implemented".to_string()
|
|
}
|
|
}
|
|
|
|
fn reduce(ast: AST) -> Option<AST> {
|
|
match ast {
|
|
Statements(stmts) => {
|
|
let mut reduction = Some(DoNothing);
|
|
for stmt in stmts.into_iter() {
|
|
reduction = reduce(stmt);
|
|
}
|
|
reduction
|
|
},
|
|
other_ast => Some(other_ast)
|
|
}
|
|
}
|