ground_fork/docs/syntax.md

Ground Syntax Guide

General syntax

Ground uses simple instructions and arguments to run code.

  instruction arg1 arg2 arg3

As an example:

  stdout "Hello, World!"

Reference a variable's value (a value reference) with a dollar sign:

  stdout $myVar

Reference a variable itself (a direct reference) with an and sign:

  stdin &myVar

Reference a line (a line reference) with a percent symbol before a line number:

  jump %10

Alternatively, set a label:

  @myLabel   # The '@' symbol denotes setting a label

and jump to that (setting labels will be discussed below):

  jump %myLabel

Reference a list (a list reference) with an asterisk:

  setlist *myList $value1 $value2 # and so on

Keywords

Note: &var can be replaced with any direct reference. $value can be replaced with a literal value or a value reference. %1 can be replaced with a line reference.

Note: In most of these functions, if a direct reference is used, the value outputted by that function will be avaliable at that variable. Any existing value inside that variable will be overwritten.

Control Flow

if

Make a decision based on a boolean. If the boolean is true, jumps to the line referenced.

Usage: if $value %1

jump

Jumps to the line referenced.

Usage: jump %1

end

Ends the program. Requires an integer for a status code.

Usage: end $intvalue

I/O

stdin

Allows input from the console.

Usage: stdin &var

stdout

Allows output to the console.

Usage: stdout $value

stdlnout

Allows output to the console, appending a new line at the end.

Usage: stdlnout $value

Variables and Lists

set

Allows you to set a variable to a value.

Usage: set &var $value

setlist

Allows you to initialize a list.

Usage: setlist *list $value1 $value2 $value3...

setlistat

Sets a list item at an index. The item at the index must already exist. Lists are index 0.

Usage: setlistat *list $intvalue $value

getlistat

Gets a list item at an index, and puts it in the variable provided. The item at the index must already exist. Lists are index 0.

Usage: getlistat *list $intvalue &var

getlistsize

Gets the size of a list and puts it in the variable provided.

Usage: getlistsize *list &var

listappend

Appends an item to a list.

Usage: listappend *list $var

String Operations (ALL WORK IN PROGRESS)

getstrsize

Gets the size of a string and puts it in the variable provided.

Usage: getstrsize $stringvalue &var

getstrcharat

Gets a character at a certain position in a string and saves it to a variable.

Usage: getstrcharat $stringvalue $intvalue &var

Maths

add

Adds two numbers. Numbers mean an integer or a double. Outputs to a direct reference.

Usage: add $value $value &var

subtract

Subtracts two numbers. Numbers mean an integer or a double. Outputs to a direct reference.

Usage: subtract $value $value &var

multiply

Multiplies two numbers. Numbers mean an integer or a double. Outputs to a direct reference.

Usage: multiply $value $value &var

divide

Divides two numbers. Numbers mean an integer or a double. Outputs to a direct reference.

Usage: divide $value $value &var

Comparisons

equal

Checks if two values are equal. Outputs a boolean to a direct reference.

Usage: equal $value $value &var

inequal

Checks if two values are not equal. Outputs a boolean to a direct reference.

Usage: inequal $value $value &var

greater

Checks if the left value is greater than the right value. Outputs a boolean to a direct reference.

Usage: greater $value $value &var

lesser

Checks if the left value is lesser than the right value. Outputs a boolean to a direct reference.

Usage: lesser $value $value &var

Type Conversions

stoi

Converts a string to an integer. Throws an error if the string cannot be turned into an integer.

Usage: stoi $stringvalue &var

stod

Converts a string to a double. Throws an error if the string cannot be turned into a double.

Usage: stod $stringvalue &var

tostring

Converts any type to a string.

Usage: tostring $value &var

Functions and function specific features (ALL WORK IN PROGRESS)

Some symbols specific to this category:

• !function: A function reference

• -type: A type reference. Can be one of the following: "-string", "-char", "-int", "-double", "-bool"

fun

Defines a function. All code between fun and endfun will be included in the function.

Usage: fun !functionname -type &var -type &var -type &var # and so on...

endfun

Ends a function definition. When a function reaches the end the argument list will be cleared.

Usage: endfun

pusharg

Adds a value to the argument list which will be passed to the function when it is called.

Usage: pusharg $value

call

Calls a function, with all the arguments in the argument list.

Usage: call !function