[ADD] Add complete file for Word counter

source/chapter-3-word-counter.rst

@@ -70,3 +70,12 @@ is present on the system with |os_file_exists|_.
 There is one catch with the |os_read_file|_ function, it returns an ``Option``
 :doc:`type <types>`. This kind of type has to be handled in your code with an
 ``or`` block that allows only specific set of :doc:`keywords <keywords>`.
+
+Once we handle the failing function and remove unnecessary printing to the
+console the program is ready and complete.
+
+Here is a challenge for you as a reader: Currently it handles only a single
+file. Try to make it handle multiple files!
+
+.. include:: vsource/word-counter-complete.v
+   :code: v

source/vsource/word-counter-complete.v

@@ -0,0 +1,53 @@
+import os
+
+struct Mode {
+    name string
+    cli_args []string
+    sep []string
+}
+
+
+const (
+    words = Mode{name: "words", cli_args: ["-w", "--words"], sep: [" ", "\n"]}
+    lines = Mode{cli_args: ["-l", "--lines"], name: "lines", sep: ["\n"]}
+    chars = Mode{name: "chars", cli_args: ["-c", "--chars"], sep: [""]}
+)
+
+
+fn parse_mode(args []string) Mode {
+    mut mode := Mode{}
+
+    if args[1] in words.cli_args {
+        mode = words
+    } else if args[1] in lines.cli_args {
+        mode = lines
+    } else if args[1] in chars.cli_args {
+        mode = chars
+    }
+    return mode
+}
+
+
+fn count(mode Mode, path string) int {
+    mut result := 0
+
+    if !os.file_exists(path) {
+        result = -1
+        return result
+    }
+
+    content := os.read_file(path) or {return result}
+    for item in content {
+        if "" in mode.sep || item.str() in mode.sep {
+            result++
+        }
+    }
+    return result
+}
+
+
+fn main() {
+    mode := parse_mode(os.args)
+    file := os.args[2]
+    println(count(mode, file))
+}