start on #13

src/app/logic/ctx.rs

@@ -1,24 +1,76 @@
-use std::{collections::HashMap, sync::RwLock};
+use std::{collections::HashMap, process::id, sync::RwLock};
 
 use evalexpr::{error::EvalexprResultValue, *};
 
 use crate::app::logic::calc::Grid;
 
-pub struct CallbackContext<'a, T: EvalexprNumericTypes = DefaultNumericTypes> {
+pub struct CallbackContext<'a> {
     variables: &'a Grid,
     eval_depth: RwLock<usize>,
-    functions: HashMap<String, Function<T>>,
+    functions: HashMap<String, Function<DefaultNumericTypes>>,
 
     /// True if builtin functions are disabled.
     without_builtin_functions: bool,
 }
 
-impl<'a, NumericTypes: EvalexprNumericTypes> CallbackContext<'a, NumericTypes> {
+impl<'a> CallbackContext<'a> {
+    fn get_functions() -> HashMap<String, Function<DefaultNumericTypes>> {
+        let mut functions = HashMap::new();
+
+        functions.insert(
+            "avg".to_string(),
+            Function::new(|arg| {
+                if arg.is_tuple() {
+                    let args = arg.as_tuple()?;
+                    let mut total: f64 = 0.;
+                    let mut count = 0f64;
+                    for i in args {
+                        total += i.as_number()?;
+                        count += 1.;
+                    }
+                    let res = total / count;
+                    Ok(Value::Float(res))
+                } else if arg.is_float() {
+                    Ok(Value::Float(arg.as_float()?))
+                } else {
+                    Err(EvalexprError::TypeError {
+                        expected: vec![ValueType::Float],
+                        actual: arg.clone(),
+                    })
+                }
+            }),
+        );
+
+        functions.insert(
+            "sum".to_string(),
+            Function::new(|arg| {
+                if arg.is_tuple() {
+                    let args = arg.as_tuple()?;
+                    let mut total: f64 = 0.;
+                    for i in args {
+                        total += i.as_number()?;
+                    }
+                    let res = total;
+                    Ok(Value::Float(res))
+                } else if arg.is_float() {
+                    Ok(Value::Float(arg.as_float()?))
+                } else {
+                    Err(EvalexprError::TypeError {
+                        expected: vec![ValueType::Float],
+                        actual: arg.clone(),
+                    })
+                }
+            }),
+        );
+
+        functions
+    }
+
     pub fn new(grid: &'a Grid) -> Self {
         Self {
             eval_depth: RwLock::new(0),
             variables: grid,
-            functions: Default::default(),
+            functions: Self::get_functions(),
             without_builtin_functions: false,
         }
     }
@@ -37,12 +89,11 @@ impl<'a, NumericTypes: EvalexprNumericTypes> CallbackContext<'a, NumericTypes> {
     }
 }
 
-impl<'a> Context for CallbackContext<'a, DefaultNumericTypes> {
+impl<'a> Context for CallbackContext<'a> {
     type NumericTypes = DefaultNumericTypes;
 
     fn get_value(&self, identifier: &str) -> Option<Value<Self::NumericTypes>> {
         if let Some(v) = self.variables.get_cell(identifier) {
-
             match v {
                 super::calc::CellType::Number(n) => return Some(Value::Float(n.to_owned())),
                 super::calc::CellType::String(_) => return None,
@@ -52,12 +103,12 @@ impl<'a> Context for CallbackContext<'a, DefaultNumericTypes> {
                     }
                     if let Ok(depth) = self.eval_depth.read() {
                         if *depth > 10 {
-                            return None
-                        }                        
+                            return None;
+                        }
                     } else {
                         // It would be unsafe to continue to process without knowing how
                         // deep we've gone.
-                        return None
+                        return None;
                     }
                     match eval_with_context(&eq[1..], self) {
                         Ok(e) => return Some(e),
@@ -67,14 +118,14 @@ impl<'a> Context for CallbackContext<'a, DefaultNumericTypes> {
                                     // If the variable isn't found, that's ~~probably~~ because
                                     // of recursive reference, considering all references
                                     // are grabbed straight from the table.
-                                    return None
-                                },
+                                    return None;
+                                }
 
-                               e => panic!("> Error {e}\n> Equation: '{eq}'"),
+                                e => panic!("> Error {e}\n> Equation: '{eq}'"),
                             }
-                        },
+                        }
                     }
-                },
+                }
             }
         }
         return None;
@@ -85,17 +136,18 @@ impl<'a> Context for CallbackContext<'a, DefaultNumericTypes> {
         identifier: &str,
         argument: &Value<Self::NumericTypes>,
     ) -> EvalexprResultValue<Self::NumericTypes> {
-        todo!()
+        if let Some(function) = self.functions.get(identifier) {
+            function.call(argument)
+        } else {
+            Err(EvalexprError::FunctionIdentifierNotFound(identifier.to_string()))
+        }
     }
 
     fn are_builtin_functions_disabled(&self) -> bool {
         self.without_builtin_functions
     }
 
-    fn set_builtin_functions_disabled(
-        &mut self,
-        disabled: bool,
-    ) -> EvalexprResult<(), Self::NumericTypes> {
+    fn set_builtin_functions_disabled(&mut self, disabled: bool) -> EvalexprResult<(), Self::NumericTypes> {
         self.without_builtin_functions = disabled;
         Ok(())
     }