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ELC language reference

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ELC language reference

Index
CONSTANT
FOR
FUNCTION
GLOBAL
IF
LET
LOCAL
RETURN
WHILE

Arrays
Comments
Function calls
TRUE and FALSE
GLOSSARY

See the glossary below for definitions of terms such as nvariable, wvariable$, etc

CONSTANT
Define a constant value to contant name that will not change as the code runs. The value can be a number (eg CONSTANT Count = 5), some words enclosed in quote marks (eg CONSTANT Result$ = "All okay"), or the enumerated boolean numbers TRUE or FALSE (eg CONSTANT Result = TRUE).

CONSTANT nvariable = number
CONSTANT wvariable$ = words

Note: Constants can only be defined outside of any functions, usually best placed at top of code for visibility

FOR
Loop through the code between { and } changing a variable from a start value to an end value. The way the variable changes can be by a specified step value each time, otherwise it will change by +1 if a step value is not specified.

FOR nvariable = nvariable|number TO nvariable|number
{
...
}

FOR nvariable = nvariable|number TO nvariable|number STEP nvariable|number
{
...
}

Note: FOR loops can only be used inside functions

FUNCTION
Define a new function whose code is contained between { and }.

FUNCTION funcname()
{
  ...
}

FUNCTION funcname(parameter)
{
  ...
}

FUNCTION funcname(parameter,parameter,...)
{
  ...
}

Note: Functions can only be defined outside of any other functions

GLOBAL
Define a new variable to be accessible from any function.

GLOBAL variable
GLOBAL variable,variable,...

Note: Global variables can only be defined outside of any functions, usually best placed at top of code for visibility

IF
Check a condition and if it is true run code between { and }.

IF wvariable$ = wvariable$|words
{
  ...
}

IF nvariable condition nvariable|number
{
  ...
}

IF test AND test ...
{
  ...
}

IF test OR test ...
{
  ...
}

IF ...
{
  ...
}
ELSE
{
  ...
}

IF ...
{
  ...
}
ELSEIF ...
{
  ...
}
ELSE
{
  ...
}

Notes:
- IF statements can only be used inside functions
- You can check more than one test in one IF or ELSEIF statement using AND and OR keywords
- You cannot mix AND's and OR's in one IF or ELSEIF statement, they must be all AND's or all OR
- You can have as many ELSEIF statements as you like
- IF/ELSEIF/ELSE statements can only be used inside functions

LET
Assign a value to a variable or perform operations on variables.

LET wvariable$ = wvariable$|words
LET wvariable$ = wvariable$|words + wvariable$|words + ...

LET nvariable = nvariable|number
LET nvariable = nvariable|number operator nvariable|number operator ...

Notes:
- Add words or word variables together to join them and make longer word sentances
- The operators are done in the order they appear in the code, just like a calculator would run them
- Local variables can only be defined inside of functions

LOCAL
Define a new variable to be accessible only in the function in which it is defined.

LOCAL variable
LOCAL variable,variable,...

Note: Local variables can only be defined inside a function

RETURN
Stop executing code from the current function and return to the calling function, or stop the app if the current function is START().

RETURN

Note: This statement can only be used inside a function

WHILE
While a condition is true and run code between { and }, checking the condition each time around the loop.

WHILE nvariable condition nvariable|number
{
  ...
}

WHILE test AND test ...
{
  ...
}

WHILE test OR test ...
{
  ...
}

Notes:
- WHILE loops can only be used inside functions
- You can check more than one test in one WHILE statement using AND and OR keywords
- You cannot mix AND's and OR's in one WHILE statement, they must be all AND's or all OR

Arrays
Arrays can be one dimensional or two dimensional.

One-dimensional arrays take the form variable[columns] and their elements are accessed using variable[column] where column is 1 to columns.

Two-dimensional arrays take the form variable[rows, columns] and their elements are accessed using variable [row,column] where row is 1 to rows and column is 1 to columns.

Both local variables and global variables can be arrays.

Comments
A comment is a line of code intended for the person reading the source code of the program. It doesn't change how the app works.

To start a comment line use // and the rest of the line is ignored by the app.

Function calls
To "call" a function (stop running code at the current position, run the called function code instead, and then come back to the current position when the called function finishes) you simply put its name on a line by itself followed by a pair of brackets.

If the function needs to be passed parameters then put these in the right order, and of the right type (numbers or words) inside the brackets separated by commas.

To ensure the program is as readable as possible function calls need to be on a line by themselves - they cannot be used in other statements like FOR, IF, LET, WHILE, etc.

For this reason if functions need to return a number they use the system global variable RETVAL, and if they need to return words they use the system global variable RETVAL$, and they can even use RETVAL and RETVAL$ to return both numbers and words. You don't need to declare RETVAL or RETVAL$ - they are declared for you by the YOUSRC runtime.

TRUE and FALSE
The values TRUE and FALSE are defined by the system ("enumerated") to have the values 1 (TRUE) and 0 (FALSE). You can use TRUE and FALSE in statements like CONSTANT, FOR, IF, LET, WHILE, etc in place of numbers.

Glossary

column	is a n number or number variable column index into an array starting at 1
columns	is the number of columns that should be stored in the array
condition	is one of the following < (smaller than) <= (smaller than or equals) = (equals) != (not equals) > (greater than) >= (greater than or equals)
funcname	is a function name (eg AskPlayersAge)
nvariable	is a number variable (eg Age)
number	is a decimal number (eg 42)
operator	is one of the following + (add) - (subtract) * (multiply) / (divide) % (modulus)
parameter	is a number parameter (eg Age) or word parameter (eg Name$)
row	is a n number or number variable row index into an array starting at 1
rows	is the number of rows that should be stored in the array
test	is a test made by an IF or ELSEIF statement, either wvariable$ = wvariable$\|words or nvariable condition nvariable\|number
variable	is a number variable (eg Age) or word variable (eg Name$)
words	is a word string in quote marks (eg "hello world")
wvariable$	is a word variable (eg Name$)

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