Make consts accessible from AbleScript code

src/consts.rs

@@ -1,19 +1,47 @@
-// NOTE(Able): Number constants
-pub const TAU: i32 = 6;
-pub const PI: i32 = 3;
-pub const E: i32 = 3;
-pub const M: i32 = 70; // @Kev#6900's weight in kilograms
-pub const PHI: i32 = 2;
-pub const GOLDEN_RATIO: i32 = 2;
-pub const WUA: i32 = 1;
-pub const EULERS_CONSTANT: i32 = 0;
-pub const GRAVITY: i32 = 10;
-pub const RNG: i32 = 12; // Kixiron#5289 Randomly rolled dice
-pub const STD_RNG: i32 = 4; //The standard random number is 4 (source: https://xkcd.com/221/)
-pub const INF: i32 = i32::max_value();
-pub const INTERESSANT: i32 = 114514; // HTGAzureX1212.#5959 interessant number
-pub const FUNNY: i32 = 69; // HTGAzureX1212.#5959 funny number
-pub const NEVERGONNAGIVEYOUUP: &str = "1452251871514141792252515212116";
+//! Number constants.
+
+use std::{cell::RefCell, collections::HashMap, rc::Rc};
+
+use crate::variables::{Value, Variable};
+
+/// Initialize a HashMap between the constant names and values
+/// accessible from within AbleScript.
+pub fn ablescript_consts() -> HashMap<String, Variable> {
+    use Value::*;
+
+    let mut map = HashMap::new();
+    for (name, value) in &[
+        ("TAU", Int(6)),                // Circumference / radius
+        ("PI", Int(3)),                 // Deprecated, do not use
+        ("EULER", Int(3)),              // Mathematical constant e
+        ("MASS", Int(70)),              // @Kev#6900's weight in kilograms
+        ("PHI", Int(2)),                // Golden ratio
+        ("WUA", Int(1)),                // 1
+        ("EULERS_CONSTANT", Int(0)),    // ???
+        ("GRAVITY", Int(10)),           // Earth surface gravity, m/s
+        ("RNG", Int(12)),               // Kixiron#5289 Randomly rolled dice
+        ("STD_RNG", Int(4)),            // The standard random number is 4 (https://xkcd.com/221/)
+        ("INF", Int(i32::max_value())), // The biggest number
+        ("INTERESSANT", Int(114514)),   // HTGAzureX1212.#5959 intéressant number
+        ("FUNNY", Int(69)),             // HTGAzureX1212.#5959 funny number
+        (
+            // Never gonna let you down
+            "NEVERGONNAGIVEYOUUP",
+            Str("1452251871514141792252515212116".to_owned()),
+        ),
+        ("OCTOTHORPE", Str("#".to_owned())), // It's an octothorpe
+        ("ANSWER", Int(ANSWER)),
+    ] {
+        map.insert(
+            (*name).to_owned(),
+            Variable {
+                melo: false,
+                value: Rc::new(RefCell::new(value.to_owned())),
+            },
+        );
+    }
+
+    map
+}
 
-pub const OCTOTHORPE: char = '#';
 pub const ANSWER: i32 = 42;

src/interpret.rs

@@ -20,7 +20,8 @@ use rand::random;
 
 use crate::{
     ast::{Expr, ExprKind, Iden, Stmt, StmtKind},
-    base_55, consts,
+    base_55,
+    consts::{self, ablescript_consts},
     error::{Error, ErrorKind},
     variables::{Functio, Value, Variable},
 };
@@ -42,12 +43,17 @@ pub struct ExecEnv {
 
 /// A set of visible variable and function definitions in a single
 /// stack frame.
-#[derive(Default)]
 struct Scope {
     /// The mapping from variable names to values.
     variables: HashMap<String, Variable>,
-    // In the future, this will store functio definitions and possibly
-    // other information.
+}
+
+impl Default for Scope {
+    fn default() -> Self {
+        Self {
+            variables: ablescript_consts(),
+        }
+    }
 }
 
 /// The reason a successful series of statements halted.