Allow implicit variable dependencies (#379)

* Allow implicit variable dependencies

* Aug-14 12h01: core.rs, Cargo.toml, Cargo.lock

* Aug-14 12h04: cases.cheat

* Aug-14 12h08: cases.cheat

Cargo.lock

@@ -174,7 +174,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "navi"
-version = "2.7.2"
+version = "2.8.0"
 dependencies = [
  "anyhow 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "dirs 2.0.2 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "navi"
-version = "2.7.2"
+version = "2.8.0"
 authors = ["Denis Isidoro <denis_isidoro@live.com>"]
 edition = "2018"
 description = "An interactive cheatsheet tool for the command-line"

README.md

@@ -237,10 +237,22 @@ The command for generating possible inputs can refer previous variables:
 # If you select "hello" for <x>, the possible values of <y> will be "hello foo" and "hello bar"
 echo <x> <y>
 
+# If you want to ignore the contents of <x> and only print <y>
+: <x>; echo <y>
+
 $ x: echo "hello hi" | tr ' ' '\n'
 $ y: echo "$x foo;$x bar" | tr ';' '\n'
 ```
 
+If you want to have implicit variable dependency, you can use the `<varname>` syntax inside a variable command:
+```sh
+# Should print /my/pictures/wallpapers
+echo "<wallpaper_folder>"
+
+$ pictures_folder: echo "/my/pictures"
+$ wallpaper_folder: echo "<pictures_folder>/wallpapers"
+```
+
 ### Multiline snippets
 
 Commands may be multiline:

src/flows/core.rs

@@ -151,10 +151,18 @@ fn replace_variables_from_snippet(
                 .get(&tags, &variable_name)
                 .ok_or_else(|| anyhow!("No suggestions"))
                 .and_then(|suggestion| {
+                    let mut new_suggestion = suggestion.clone();
+                    new_suggestion.0 = replace_variables_from_snippet(
+                        &new_suggestion.0,
+                        tags,
+                        variables.clone(),
+                        config,
+                    )?;
+
                     prompt_with_suggestions(
                         variable_name,
                         &config,
-                        suggestion,
+                        &new_suggestion,
                         interpolated_snippet.clone(),
                     )
                 })

src/structures/cheat.rs

@@ -8,6 +8,7 @@ fn gen_key(tags: &str, variable: &str) -> u64 {
     format!("{};{}", tags, variable).hash_line()
 }
 
+#[derive(Clone)]
 pub struct VariableMap(HashMap<u64, Suggestion>);
 
 impl VariableMap {

tests/no_prompt_cheats/cases.cheat

@@ -28,15 +28,26 @@ echo "<language2> is cool"
 # multiple words -> "lorem foo bar ipsum"
 echo "lorem <multiword> ipsum"
 
-# variable dependency -> "2 12 a 2"
+# variable dependency, full -> "2 12 a 2"
 echo "<x> <x2> <y> <x>"
 
+# variable dependency, we can ignore intermediate values -> "12"
+: <x>; echo "<x2>"
+
+# nested used value -> "path: /my/pictures/wallpapers"
+echo "path: <wallpaper_folder>"
+
+# nested unused value -> "path: /my/pictures"
+echo "path: <pictures_folder>"
+
 $ x: echo '2'
 $ x2: echo "$((x+10))"
 $ y: echo 'a'
 $ language: echo '0  rust      rust-lang.org' --- --column 2
 $ language2: echo '1;clojure;clojure.org' --- --column 2 --delimiter ';'
 $ multiword: echo 'foo bar'
+$ pictures_folder: echo "/my/pictures"
+$ wallpaper_folder: echo "<pictures_folder>/wallpapers"
 
 # this should be displayed -> "hi"
 echo hi