partiql/sql/
field.rs

1use std::str::FromStr;
2
3use crate::parser;
4use crate::sql::Env;
5use crate::sql::Expr;
6use crate::value::PqlValue;
7
8#[derive(Debug, Default, Clone, PartialEq)]
9pub struct Field {
10    pub expr: Expr,
11    pub alias: Option<String>,
12}
13
14impl FromStr for Field {
15    type Err = anyhow::Error;
16
17    fn from_str(s: &str) -> anyhow::Result<Self> {
18        match parser::expressions::parse_field(s) {
19            Ok((_, field)) => Ok(field),
20            Err(nom::Err::Error(err)) => {
21                eprint!("{}", err);
22                anyhow::bail!("failed")
23            }
24            _ => todo!(),
25        }
26    }
27}
28
29impl Field {
30    pub fn expand_fullpath(&self, env: &Env) -> Self {
31        Self {
32            expr: env.expand_fullpath(&self.expr),
33            alias: self.alias.to_owned(),
34        }
35    }
36
37    pub fn evaluate(self, env: &Env) -> PqlValue {
38        let value = self.expr.eval(&env);
39        value
40    }
41
42    pub fn rename(self) -> (String, Expr) {
43        if let Some(alias) = self.alias {
44            (alias, self.expr)
45        } else {
46            let alias = match &self.expr {
47                Expr::Selector(selector) => selector.to_vec().last().unwrap().to_string(),
48                _ => todo!(),
49            };
50            (alias, self.expr)
51        }
52    }
53}
partiql/sql/field.rs

partiql/sql/
field.rs
