Update Syntax and README

README.md

@@ -2,30 +2,70 @@
 
 A pseudocode interpreter designed to be compatible with the Cambridge IGCSE and A level pseudocode [syntax](./Syntax.md)
 
-![PseudoEngine2](https://user-images.githubusercontent.com/44658109/220901152-5a794d58-de15-4028-91b0-fbebee033a70.png)
+![Demo](./HelloWorld.gif)
 
 ## The REPL
-The REPL stands for Read Execute Print Loop and is an interface where pseudocode statements can be entered. The statement is immediately executed after it is entered and the result is printed to the console(if any)
+The REPL stands for **R**ead **E**xecute **P**rint **L**oop and is an interface where pseudocode statements can be entered. The statement is immediately executed after it is entered and the result or potential errors are printed to the console to make it easy for debugging.
+
+```
+> 5 + 2 * 3
+11
+> LEFT("ABCD", 2)
+"AB"
+> x <- 1 / 0
+
+Runtime Error in file <stdin>:
+Division by 0
+
+Traceback:
+Program, line 1, column 9
+```
 
 ## Usage
-- Run the following commands in terminal/powershell in the directory of the executable.
+### Launching the REPL
+Lanuch the program directly by double clicking the [executable](https://github.com/SingularityT3/PseudoEngine2/releases) \
+**OR** \
+Run it in the terminal with no arguements
+
+### Running files in the REPL
+The REPL can be used to run files using `RUNFILE <file>`. \
+For example, here is a simple hello world program stored in the file `hello.pseudo`
+```
+OUTPUT "Hello World!"
+```
+\
+Run it with `RUNFILE hello.pseudo` \
+Example output:
+```
+PseudoEngine2 v1.0.0 REPL
+Enter 'EXIT' to quit
+> RUNFILE hello.pseudo
+Running file hello.pseudo
+Hello World!
+
+Program exited successfully
+>
+```
+> Tip:
+> The program must be stored in the _same folder_ as the executable **or** the full path of the program has to be mentioned when using `RUNFILE`
+
 
-  Windows:
-  ```
-  PseudoEngine2.exe [filename]
-  ```
-  Linux/Unix:
-  ```
-  ./PseudoEngine2 [filename]
-  ```
-  NOTE: `PseudoEngine2` would be replaced by the name of the executable which may be something like `Pseudoengine2-v0.5.exe` if it is downloaded from the [releases](https://github.com/SingularityT3/PseudoEngine2/releases)
+### Running files from the terminal
+Navigate to the executable and run it providing the path of the program file as an arguement similar to `RUNFILE`
 
-  Filename is an optional arguement. If it is provided the program in the corresponding file is run otherwise the REPL is launched.
+Windows:
+```
+PseudoEngine2.exe <filepath>
+```
+Linux/Unix:
+```
+./PseudoEngine2 <filepath>
+```
 
-- Alternatively, double click the executable file if supported by the OS to directly start the REPL. It is also possible to run files from the REPL using the command `RUNFILE <filename>`.
+Make sure you replace `PseudoEngine2` with the actual name of the executable or rename the executable
 
 ## Examples
-See [examples](./examples) and [tests](./tests)
+See [examples](./examples)
 
 ## Building
 Make sure cmake and a c++ compiler is installed, then clone the repository and inside its folder run the following commands:

Syntax.md

@@ -416,4 +416,5 @@ CLOSEFILE <filename>
 - `CONTINUE` - Skip to next iteration of loop
 - `ELSE IF` - Alternative to reduce nesting
 - Alternate method of type conversion(apart from in-built functions): `<data type>(<value>)`. For example: `INTEGER("57")` 
+- Math functions like `SIN`, `EXP`
 - Character escape codes like `\n`, `\t` etc.