truecalc_core/eval/context/
mod.rs

1use std::collections::HashMap;
2use crate::types::Value;
3
4/// Holds the named variable bindings for a formula evaluation.
5///
6/// All keys are stored and looked up in uppercase, so variable names are
7/// case-insensitive (`A1`, `a1`, and `A1` all refer to the same binding).
8pub struct Context {
9    pub vars: HashMap<String, Value>,
10    /// Pinned "now" for volatile date functions (`NOW`, `TODAY`), as a
11    /// local-time spreadsheet serial datetime (integer part = day serial,
12    /// fraction = time of day). `None` ⇒ the functions read the ambient
13    /// local clock. Set via [`crate::Engine::evaluate_at`] (P1.4, issue #526).
14    pub now_serial: Option<f64>,
15}
16
17impl Context {
18    /// Create a `Context` from a map of variable name → value.
19    /// Keys are normalised to uppercase on insertion.
20    pub fn new(vars: HashMap<String, Value>) -> Self {
21        let normalized = vars.into_iter()
22            .map(|(k, v)| (k.to_uppercase(), v))
23            .collect();
24        Self { vars: normalized, now_serial: None }
25    }
26
27    /// Create an empty `Context` with no variable bindings.
28    pub fn empty() -> Self {
29        Self { vars: HashMap::new(), now_serial: None }
30    }
31
32    /// Look up a variable by name (case-insensitive). Returns `Value::Empty` if not found.
33    pub fn get(&self, name: &str) -> Value {
34        self.vars
35            .get(&name.to_uppercase())
36            .cloned()
37            .unwrap_or(Value::Empty)
38    }
39
40    /// Look up a binding by name (case-insensitive), distinguishing an absent
41    /// binding (`None`) from one explicitly bound to [`Value::Empty`]
42    /// (`Some(Value::Empty)`). Used by the evaluator to decide whether a
43    /// reference should fall through to the resolver.
44    pub fn lookup(&self, name: &str) -> Option<Value> {
45        self.vars.get(&name.to_uppercase()).cloned()
46    }
47
48    /// Insert or overwrite a binding. Returns the previous value if one existed.
49    pub fn set(&mut self, name: String, value: Value) -> Option<Value> {
50        self.vars.insert(name.to_uppercase(), value)
51    }
52
53    /// Remove a binding. Used to restore context after lambda/let evaluation.
54    pub fn remove(&mut self, name: &str) {
55        self.vars.remove(&name.to_uppercase());
56    }
57}
58
59#[cfg(test)]
60mod tests;
truecalc_core/eval/context/mod.rs

truecalc_core/eval/context/
mod.rs
