add some examples; move some examples

crystal/README.md

@@ -20,6 +20,11 @@
 
 ## Ideas for slides
 
+
+What are these ? and ! mean at the end of the functions and sometimes end of various statements?
+What does   !something.empty? and why don't you write ¡empty! anyway? That would at least make sense...
+
+
 The need to recompile the whole thing before I run it and the fact that compilation is slow makes life of a (web) developer hard.
 The Jinja Template system of Johannes that does not need to be compiled makes at least the HTML development much faster.
 
@@ -39,6 +44,7 @@ What is "flag?"  ? I saw it in the source code of Kemal, but I don't see it defi
 
 GitHub Actions configurators: https://crystal-lang.github.io/install-crystal/configurator.html
 
+
 Yak Shaving
 
 https://forum.crystal-lang.org/ has around 500 users.

crystal/directories.md

@@ -5,18 +5,18 @@
 {id: list-directory}
 {i: Dir}
 
-![](examples/list_dir.cr)
+![](examples/filesystem/list_dir.cr)
 
 ## List directory tree
 {id: directory-tree}
 {i: Dir}
 {i: glob}
-![](examples/traverse_tree.cr)
+![](examples/filesystem/traverse_tree.cr)
 
 ## Get Current workding directory (cwd, pwd)
 {id: current-working-directory}
 
-![](examples/cwd.cr)
+![](examples/filesystem/cwd.cr)
 
 ## Temporary directory
 {id: temporary-directory}
@@ -27,9 +27,9 @@
 {i: rm_rf}
 {i: cd}
 
-![](examples/tempdir.cr)
+![](examples/filesystem/tempdir.cr)
 
 ## Tempdir function
 {id: tempdir}
 
-![](examples/tempdir_function.cr)
+![](examples/filesystem/tempdir_function.cr)

crystal/examples/regexes/gsub.cr

@@ -0,0 +1,5 @@
+puts "The cat is here".gsub("cat", "dog")
+puts "The cat is here".gsub("cat") {"dog"}
+
+puts "The cat is here".gsub("cat") {|match| match.reverse }
+puts "The cat is here".gsub(/c../) {|match| match.reverse }

crystal/examples/strings/split_characters.cr

@@ -1,3 +1,6 @@
 text = "black cat"
 puts text.split("")
 puts text.split("").sort
+
+
+puts text.chars

crystal/examples/strings/split_characters.out

@@ -1,2 +1,3 @@
 ["b", "l", "a", "c", "k", " ", "c", "a", "t"]
 [" ", "a", "a", "b", "c", "c", "k", "l", "t"]
+['b', 'l', 'a', 'c', 'k', ' ', 'c', 'a', 't']

crystal/examples/use_yaml.cr → crystal/examples/yaml/use_yaml.cr

@@ -1,6 +1,6 @@
 require "yaml"
 
-data = File.open("examples/crystal.yml") do |file|
+data = File.open("examples/yaml/crystal.yml") do |file|
   YAML.parse(file)
 end
 puts data

crystal/other.md

@@ -289,3 +289,10 @@ require "some_name"         # Find it somewhere (standard library, src directory
 
 ![](examples/int64_zero.cr)
 
+## Resources
+{id: resources}
+
+* [Crystal Programming](https://www.youtube.com/watch?v=DxFP-Wjqtsc) by Derek Banas from 2018
+* [LuckyCast](https://luckycasts.com/)
+
+

crystal/regexes.md

@@ -18,3 +18,8 @@
 ![](examples/regexes/substitute.cr)
 ![](examples/regexes/substitute.out)
 
+## gsub
+{id: gsub}
+
+![](examples/regexes/gsub.cr)
+

crystal/strings.md

@@ -130,6 +130,8 @@
 
 ## Split characters
 {id: split-characters}
+{i: split}
+{i: chars}
 
 ![](examples/strings/split_characters.cr)
 ![](examples/strings/split_characters.out)

crystal/yaml.md

@@ -7,8 +7,8 @@
 
 * [YAML](https://crystal-lang.org/api/YAML.html)
 
-![](examples/crystal.yml)
-![](examples/use_yaml.cr)
+![](examples/yaml/crystal.yml)
+![](examples/yaml/use_yaml.cr)