add gpsl bin

.gitignore

@@ -0,0 +1 @@
+target/

src/bin/gpsl.rs

@@ -0,0 +1,29 @@
+use gpsl::{
+    gpsl::GPSL,
+    source::Source,
+    std::*,
+    tokenizer::Tokenizer,
+    parser::Parser
+};
+use std::{fs, env, collections::HashMap};
+fn main() {
+    env::set_var("RUST_LOG", "info");
+    env_logger::init();
+
+    let args: Vec<String> = env::args().collect();
+    let mut source = Source::new(fs::read_to_string(&(args.last().unwrap())).expect("Cannot read file."));
+
+    let mut tokenizer = Tokenizer::new();
+    tokenizer.tokenize(&mut source);
+
+    let mut parser = Parser {
+        tokenizer,
+        local_vars: HashMap::new()
+    };
+
+    let mut gpsl = GPSL::new(source, Some(parser.functions().unwrap()), vec![STD_FUNC]);
+    let res = gpsl.run("main".to_string(), vec![]);
+    if let Err(err) = res {
+        println!("Error: {:?}", err);
+    }
+}

test.gpsl

@@ -0,0 +1,5 @@
+fn main() {
+    let a: String;
+    a = "test";
+    println(a);
+}