Working seq

Author: Francis Murillo

seq/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "seq"
 version = "0.1.0"
-authors = ["GrayJack <gr41.j4ck@gmail.com>", "FrancisMurillo <francisavmurillo@gmail.com>"]
+authors = ["GrayJack <gr41.j4ck@gmail.com>" , "FrancisMurillo <francisavmurillo@gmail.com>"]
 build = "build.rs"
 edition = "2018"
 

seq/src/main.rs

@@ -1,13 +1,98 @@
 use std::process;
 
-use clap::{load_yaml, App};
+use clap::{load_yaml, App, AppSettings};
+
+#[derive(Clone,Debug)]
+pub struct Seq {
+    current: f64,
+    stop: f64,
+    step: f64,
+}
+
+impl Iterator for Seq {
+    type Item = f64;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.step.is_sign_positive() && self.current <= self.stop {
+            let result = self.current.clone();
+
+            self.current += self.step;
+
+            Some(result)
+        } else if self.step.is_sign_negative() && self.current >= self.stop
+{
+            let result = self.current.clone();
+
+            self.current += self.step;
+
+            Some(result)
+        } else {
+            None
+        }
+    }
+}
+
+
+fn parse_number(text: &str) -> Result<f64, ()> {
+    text
+        .parse::<f64>()
+        .map_err(|_| ())
+}
+
+fn check_nan(value: f64) -> Result<f64, ()> {
+    if value.is_nan() { Err(()) } else { Ok(value)}
+}
+
+fn check_zero(value: f64) -> Result<f64, ()> {
+    if value == 0.0 { Err(()) } else { Ok(value)}
+}
 
 fn main() {
     let yaml = load_yaml!("seq.yml");
-    let matches = App::from_yaml(yaml).get_matches();
+    let matches = App::from_yaml(yaml)
+        .setting(AppSettings::AllowNegativeNumbers)
+        .get_matches();
+
+    let (raw_first, raw_increment, raw_last) = match  (matches.value_of("FIRST"), matches.value_of("SECOND"), matches.value_of("THIRD")) {
+        (Some(last), None, None) =>
+            ("1", "1", last),
+        (Some(first), Some(last), None) =>
+            (first, "1", last),
+        (Some(first), Some(increment), Some(last)) =>
+            (first, increment, last),
+        _ => {
+            eprintln!("seq: Missing operands.\nTry 'seq --help' for more information.");
+            process::exit(1);
+        }
+    };
+
+    let first = parse_number(raw_first)
+        .and_then(check_nan)
+        .unwrap_or_else(|_| {
+            eprintln!("seq: Invalid FIRST.\nTry 'sleep --help' for more information.");
+            process::exit(1);
+        });
+
+    let last = parse_number(raw_last)
+        .and_then(check_nan)
+        .unwrap_or_else(|_| {
+            eprintln!("seq: Invalid LAST.\nTry 'sleep --help' for more information.");
+            process::exit(1);
+        });
+
+    let increment = parse_number(raw_increment)
+        .and_then(check_nan)
+        .and_then(check_zero)
+        .unwrap_or_else(|_| {
+            eprintln!("seq: Invalid INCREMENT.\nTry 'sleep --help' for more information.");
+            process::exit(1);
+        });
 
+    let iter = Seq { current: first, stop: last, step: increment};
 
-    std::dbg!(matches);
+    for index in iter {
+        println!("{}", index);
+    }
 
     // let numbers = match matches.values_of("NUMBER") {
     //     Some(values) => values,

seq/src/seq.yml

@@ -20,7 +20,8 @@ args:
 
 
           This must not be NaN. If omitted, defaults to 1.
-    - INCREMENT:
+        required: true
+    - SECOND:
         help: >
           The step/increment added after each preceeding number in the
           sequence.
@@ -33,7 +34,8 @@ args:
           number; if less than, this should be a negative number. This
           must not be 0 or NaN. If omitted, defaults to 1 even if FIRST
           is greater than LAST.
-    - LAST:
+        required: false
+    - THIRD:
         help: >
           The limit of the sequence.
         long_help: >
@@ -43,3 +45,4 @@ args:
           If the next number in a sequence exceeds above or falls below
           LAST whether STEP is positive or negative respectively, the
           sequence ends. This must not be NaN.
+        required: false

sleep/src/main.rs

@@ -11,7 +11,7 @@ fn main() {
         Some(values) => values,
         None => {
             eprintln!("sleep: Missing operand.\nTry 'sleep --help' for more information.");
-            process::exit(1);
+            process::exit(1);2
         }
     };