Added LT, GT, LTE, and GTE functions, and big test coverage

src/segment.rs

@@ -16,7 +16,7 @@
  */
 use std::fmt;
 use std::marker::PhantomData;
-use std::ops::{Add, Sub, Mul, Div, Index};
+use std::ops::{Add, Div, Index, Mul, Sub};
 
 // Container
 #[derive(Debug, Default)]
@@ -321,7 +321,6 @@ impl Sub<Ctr> for Ctr {
     }
 }
 
-
 impl Mul<Ctr> for Ctr {
     type Output = Ctr;
 

src/stl.rs

@@ -291,7 +291,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::EXP_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::exp_callback)),
-        }
+        },
     );
 
     syms.insert(
@@ -302,7 +302,51 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::MOD_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::mod_callback)),
-        }
+        },
+    );
+
+    syms.insert(
+        "gt?".to_string(),
+        Symbol {
+            name: String::from("gt?"),
+            args: Args::Lazy(2),
+            conditional_branches: false,
+            docs: math::ISGT_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(math::isgt_callback)),
+        },
+    );
+
+    syms.insert(
+        "lt?".to_string(),
+        Symbol {
+            name: String::from("lt?"),
+            args: Args::Lazy(2),
+            conditional_branches: false,
+            docs: math::ISLT_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(math::islt_callback)),
+        },
+    );
+
+    syms.insert(
+        "gte?".to_string(),
+        Symbol {
+            name: String::from("gt?"),
+            args: Args::Lazy(2),
+            conditional_branches: false,
+            docs: math::ISGTE_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(math::isgte_callback)),
+        },
+    );
+
+    syms.insert(
+        "lte?".to_string(),
+        Symbol {
+            name: String::from("lt?"),
+            args: Args::Lazy(2),
+            conditional_branches: false,
+            docs: math::ISLTE_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(math::islte_callback)),
+        },
     );
 
     Ok(())

src/stl/math.rs

@@ -264,3 +264,97 @@ pub fn mod_callback(ast: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
 
     Ok(Ctr::Seg(ret))
 }
+
+pub const ISGT_DOCSTRING: &str = "takes two args, which must both evaluate to an Integer or Float.
+Returns true or false according to whether the first argument is bigger than the second argument.
+May panic if an integer larger than a max f64 is compared to a float.";
+
+pub fn isgt_callback(ast: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
+    let first = *ast.car.clone();
+    if !isnumeric(&first) {
+        return Err("first argument must be numeric".to_string());
+    }
+    let second: Ctr;
+    if let Ctr::Seg(ref s) = *ast.cdr {
+        second = *s.car.clone();
+    } else {
+        return Err("impossible error: needs two arguments".to_string());
+    }
+    if !isnumeric(&second) {
+        return Err("second argument must be numeric".to_string());
+    }
+
+    match first {
+        Ctr::Float(lf) => match second {
+            Ctr::Float(rf) => Ok(Ctr::Bool(lf > rf)),
+            Ctr::Integer(ri) => Ok(Ctr::Bool(lf > ri as f64)),
+            _ => Err("gt? not implemented for these arguments".to_string()),
+        },
+        Ctr::Integer(li) => match second {
+            Ctr::Float(rf) => Ok(Ctr::Bool(li as f64 > rf)),
+            Ctr::Integer(ri) => Ok(Ctr::Bool(li > ri)),
+            _ => Err("gt? not implemented for these arguments".to_string()),
+        },
+
+        _ => Err("gt? not implemented for these arguments".to_string()),
+    }
+}
+
+pub const ISLT_DOCSTRING: &str = "takes two args, which must both evaluate to an Integer or Float.
+Returns true or false according to whether the first argument is smaller than the second argument.
+May panic if an integer larger than a max f64 is compared to a float.";
+
+pub fn islt_callback(ast: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
+    let first = *ast.car.clone();
+    if !isnumeric(&first) {
+        return Err("first argument must be numeric".to_string());
+    }
+    let second: Ctr;
+    if let Ctr::Seg(ref s) = *ast.cdr {
+        second = *s.car.clone();
+    } else {
+        return Err("impossible error: needs two arguments".to_string());
+    }
+    if !isnumeric(&second) {
+        return Err("second argument must be numeric".to_string());
+    }
+
+    match first {
+        Ctr::Float(lf) => match second {
+            Ctr::Float(rf) => Ok(Ctr::Bool(lf < rf)),
+            Ctr::Integer(ri) => Ok(Ctr::Bool(lf < ri as f64)),
+            _ => Err("gt? not implemented for these arguments".to_string()),
+        },
+        Ctr::Integer(li) => match second {
+            Ctr::Float(rf) => Ok(Ctr::Bool((li as f64) < rf)),
+            Ctr::Integer(ri) => Ok(Ctr::Bool(li < ri)),
+            _ => Err("gt? not implemented for these arguments".to_string()),
+        },
+
+        _ => Err("gt? not implemented for these arguments".to_string()),
+    }
+}
+
+pub const ISGTE_DOCSTRING: &str = "takes two args, which must both evaluate to an Integer or Float.
+Returns true or false according to whether the first argument is greater than or equal to the second argument.
+May panic if an integer larger than a max f64 is compared to a float.";
+
+pub fn isgte_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
+    if let Ctr::Bool(b) = islt_callback(ast, syms)? {
+        Ok(Ctr::Bool(!b))
+    } else {
+        Err("impossible state: islt returned non-bool".to_string())
+    }
+}
+
+pub const ISLTE_DOCSTRING: &str = "takes two args, which must both evaluate to an Integer or Float.
+Returns true or false according to whether the first argument is less than or equal to the second argument.
+May panic if an integer larger than a max f64 is compared to a float.";
+
+pub fn islte_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
+    if let Ctr::Bool(b) = isgt_callback(ast, syms)? {
+        Ok(Ctr::Bool(!b))
+    } else {
+        Err("impossible state: islt returned non-bool".to_string())
+    }
+}

src/sym.rs

@@ -145,7 +145,7 @@ impl Args {
                 } else {
                     return Err("expected no args".to_string());
                 }
-            },
+            }
 
             Args::Infinite => {
                 if !args.is_empty() {
@@ -153,7 +153,7 @@ impl Args {
                 } else {
                     return Err("expected args but none were provided".to_string());
                 }
-            },
+            }
 
             Args::Lazy(ref num) => {
                 let called_arg_count = args.len();
@@ -168,7 +168,7 @@ impl Args {
                 } else if let Ctr::None = *args.car {
                     return Err(format!("expected {} args. Got 0.", num,));
                 }
-            },
+            }
 
             Args::Strict(ref arg_types) => {
                 let mut idx: usize = 0;
@@ -203,7 +203,7 @@ impl Args {
                         return Err("too few arguments".to_string());
                     }
                 }
-            },
+            }
         }
 
         Ok(())