From 7dcee06e99439f14b9916acc85c872ed5480f937 Mon Sep 17 00:00:00 2001
From: Phodal Huang <h@phodal.com>
Date: Mon, 7 Nov 2022 22:31:36 +0800
Subject: [PATCH] feat: try compare with exprtk #13

---
 extensions/ext-computing/Cargo.toml           |  1 +
 .../ext-computing/src/expr/grammar.pest       |  2 +-
 extensions/ext-computing/src/expr/parser.rs   | 22 ++++++++++++++++---
 extensions/ext-computing/src/expr/token.rs    |  3 +++
 4 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/extensions/ext-computing/Cargo.toml b/extensions/ext-computing/Cargo.toml
index eed7e94..1d77c6d 100644
--- a/extensions/ext-computing/Cargo.toml
+++ b/extensions/ext-computing/Cargo.toml
@@ -22,3 +22,4 @@ lazy_static = "1.4.0"
 actix-web = "4"
 tokio = { version = "1", features = ["full"] }
 futures = "0.3.18"
+exprtk_rs="0.1.0"
diff --git a/extensions/ext-computing/src/expr/grammar.pest b/extensions/ext-computing/src/expr/grammar.pest
index 1108fcb..c02d9b1 100644
--- a/extensions/ext-computing/src/expr/grammar.pest
+++ b/extensions/ext-computing/src/expr/grammar.pest
@@ -3,7 +3,7 @@ program     = _{ SOI ~ expr ~ EOI }
 stmt        = _{ assign | expr }
 assign      = { ident ~ "=" ~ expr }
 expr        = { prefix* ~ primary ~ postfix* ~ (infix ~ prefix* ~ primary ~ postfix* )* }
-primary     = _{ constants | function | variable | num | "(" ~ expr ~ ")"  }
+primary     = _{ (num ~ constants) | constants | function | variable | num | "(" ~ expr ~ ")" }
 infix       = _{ sub | add | mul | div | pow | percentOf | percentOn | rightShift | leftShift | modulus }
 prefix      = _{ neg }
 postfix     = _{ fac }
diff --git a/extensions/ext-computing/src/expr/parser.rs b/extensions/ext-computing/src/expr/parser.rs
index ce1797b..a982d49 100644
--- a/extensions/ext-computing/src/expr/parser.rs
+++ b/extensions/ext-computing/src/expr/parser.rs
@@ -18,6 +18,7 @@ lazy_static! {
           .op(Op::infix(Rule::mul, Assoc::Left) | Op::infix(Rule::div, Assoc::Left))
           .op(Op::infix(Rule::pow, Assoc::Right))
           .op(Op::postfix(Rule::fac))
+          .op(Op::postfix(Rule::e))
           .op(Op::prefix(Rule::neg))
     };
 }
@@ -27,6 +28,7 @@ pub fn parse(input: &str, vars: &BTreeMap<String, Instruction>) -> f64 {
   match Calculator::parse(Rule::program, input) {
     Ok(mut pairs) => {
       let expr = parse_expr(pairs.next().unwrap().into_inner());
+      println!("expr: {:?}", expr);
       namespace.eval(expr)
     }
     Err(err) => {
@@ -102,6 +104,11 @@ fn parse_expr(pairs: Pairs<Rule>) -> Instruction {
       Rule::pow => Instruction::Pow { lhs: Box::from(lhs), rhs: Box::from(rhs) },
       _ => panic!("unimplemented: {:?}", op),
     })
+    .map_postfix(|lhs, op: Pair<Rule>| match op.as_rule() {
+      Rule::fac => Instruction::Fac { val: Box::from(lhs) },
+      Rule::e => Instruction::Mul { lhs: Box::from(lhs), rhs: Box::from(Instruction::Const(std::f64::consts::E)) },
+      _ => panic!("unimplemented: {:?}", op),
+    })
     .parse(pairs)
 }
 
@@ -154,13 +161,22 @@ mod tests {
   }
 
   #[test]
-  fn function_sqrt() {
+  fn function_demo() {
     assert_eq!(parse("sqrt(4)", &Default::default()), 2.0);
     let vars = BTreeMap::from_iter(vec![("x".to_string(), Instruction::Const(2.0))]);
     assert_eq!(parse("sqrt(1 - (3 / x^2))", &vars), 0.5);
     assert_eq!(parse("sqrt(1 - (3 / 3^2))", &vars), 0.816496580927726);
+  }
+
+  #[test]
+  fn const_e() {
+    let vars2 = BTreeMap::from_iter(vec![("x".to_string(), Instruction::Const(2.0))]);
+    assert_eq!(parse("sin(2.34e-3 * x)", &vars2), 0.004679982916146709);
+
+    let mut symbol_table = exprtk_rs::SymbolTable::new();
+    symbol_table.add_variable("x", 2.0).unwrap().unwrap();
+    let mut expr = exprtk_rs::Expression::new("sin(2.34e-3 * x)", symbol_table).unwrap();
 
-    let vars2 = BTreeMap::from_iter(vec![("x".to_string(), Instruction::Const(3.0))]);
-    assert_eq!(parse("sin(2.34e-x *2)", &vars2), 0.00467998291);
+    assert_eq!(expr.value(), 0.004679982916146709);
   }
 }
diff --git a/extensions/ext-computing/src/expr/token.rs b/extensions/ext-computing/src/expr/token.rs
index f6e93e9..380c335 100644
--- a/extensions/ext-computing/src/expr/token.rs
+++ b/extensions/ext-computing/src/expr/token.rs
@@ -96,6 +96,9 @@ pub enum Instruction {
   // Functions
   FuncSin,
   FuncCos,
+  Fac {
+    val: Box<Instruction>,
+  },
 
   // Others
   // with Builtin Types?