Initial commit

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*.cr]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true

.gitignore

@@ -0,0 +1,9 @@
+/docs/
+/lib/
+/bin/
+/.shards/
+*.dwarf
+
+# Libraries don't need dependency lock
+# Dependencies will be locked in applications that use them
+/shard.lock

LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2021 grimmigerFuchs <dominic.grimm@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

@@ -0,0 +1,41 @@
+# sexpr
+
+A small s-expression parser based on [fast-sexpr](https://www.npmjs.com/package/fast-sexpr).
+
+## Installation
+
+1. Add the dependency to your `shard.yml`:
+
+   ```yaml
+   dependencies:
+     sexpr:
+       github: grimmigerfuchs/sexpr
+   ```
+
+2. Run `shards install`
+
+## Usage
+
+```crystal
+require "sexpr"
+
+source = "
+(test (arg1 arg2) something else)
+(another object (with (nests (too))))
+"
+
+pp Sexpr.parse(source)
+"
+```
+
+## Contributing
+
+1. Fork it (<https://github.com/grimmigerfuchs/sexpr/fork>)
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create a new Pull Request
+
+## Contributors
+
+- [grimmigerFuchs](https://github.com/grimmigerfuchs) - creator and maintainer

shard.yml

@@ -0,0 +1,11 @@
+name: sexpr
+description: |
+  A small s-expression parser based on fast-sexpr
+version: 0.1.0
+
+authors:
+  - grimmigerFuchs <dominic.grimm@gmail.com>
+
+crystal: 1.2.0
+
+license: MIT

src/sexpr.cr

@@ -0,0 +1,71 @@
+# Based on fast-sexpr (https://www.npmjs.com/package/fast-sexpr)
+
+module Sexpr
+  extend self
+
+  VERSION = {{ `shards version`.stringify.chomp }}
+
+  alias Node = String | Body
+  alias Body = Array(String) | Array(Node)
+
+  private class Wrapper
+    private property i = 0
+    private property source : String
+
+    private module Terms
+      STRING = /"/
+      SPACE  = /\s/
+      LIST   = /(#{SPACE})|[()]/
+    end
+
+    def initialize(@source : String)
+    end
+
+    private def get_char : Char?
+      if @i == @source.size
+        return nil
+      end
+
+      char = @source[@i]
+      @i += 1
+      char
+    end
+
+    private def read_value(is_terminator : Regex) : String
+      value = ""
+      while !is_terminator.matches?(strChar = get_char.to_s)
+        value += strChar
+      end
+
+      value
+    end
+
+    private def un_get_char
+      @i -= 1
+    end
+
+    def parse : Body
+      body = [] of Node
+
+      while char = get_char
+        if char == ')'
+          break
+        elsif char == '('
+          body << parse
+        elsif char == '"'
+          body << read_value(Terms::STRING)
+        elsif !Terms::SPACE.matches?(char.to_s)
+          un_get_char
+          body << read_value(Terms::LIST)
+          un_get_char
+        end
+      end
+
+      body
+    end
+  end
+
+  def parse(source : String) : Body
+    Wrapper.new(source).parse
+  end
+end