Difference between revisions of "TeaScript Syntax"

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====Comparing Operators====
 
====Comparing Operators====
 
Note that all <code>comparative operators</code> require both sides use the same data type. (You can compare numbers with other numbers and strings with other strings, but you cannot compare numbers with strings)
 
Note that all <code>comparative operators</code> require both sides use the same data type. (You can compare numbers with other numbers and strings with other strings, but you cannot compare numbers with strings)
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! colspan="3" style="font-size:large; background-color:#9b59b6; color:#ffffff;" |Comparitive Operators
 
! colspan="3" style="font-size:large; background-color:#9b59b6; color:#ffffff;" |Comparitive Operators
 
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<code>Logical operators</code> only work on numbers. They are commonly used with -1 and 0 to represent true and false respectively. Other numbers can be used but it may yield different patterns.
 
<code>Logical operators</code> only work on numbers. They are commonly used with -1 and 0 to represent true and false respectively. Other numbers can be used but it may yield different patterns.
  
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! colspan="9" style="font-size:large; background-color:#9b59b6; color:#ffffff;" |Logical Operators
 
! colspan="9" style="font-size:large; background-color:#9b59b6; color:#ffffff;" |Logical Operators
 
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Revision as of 07:43, 22 December 2019

Data Types and Variables

User Variables

User variables can be access in the variable menu or by pressing ctrl+i. All of these variables must be created using this interface.

Doubles & Strings

By clicking the Add button in the variable interface you create a user variable.

You may also select if the variable is a global user variable. Local user variables can only exist in a single level and the value is reset every time the level begins. Global variables save the value per level and remembers the value even after quitting the game.

Variable Naming Standard

  • Names are not case sensitive.
  • Names must not contain spaces.
  • Names must be made using a combination of using letters and numbers.
  • Names must start with a letter

User variables work in an unusual way compared to other scripting languages. A user variable has two sides, a double and a string. There are different methods to access each side

' By creating a variable called "myVar" in the interface you can...
' === Access doubles
'Local
val(myVar) or v(myVar)

'Global
gval(myVar) or gv(myVar)

'Local Concatenation in TXTCreate and Event Messages
&val(myVar)

'Global Concatenation in TXTCreate and Event Messages
&gval(myVar)

' === Access strings
'Local
str(myVar)

'Global
gstr(myVar)

'Local Concatenation in TXTCreate and Event Messages
$val(myVar)

'Global Concatenation in TXTCreate and Event Messages
$gvl(myVar)


 1 ' === Example
 2 
 3 v(myVar) = 5
 4 str(myVar) = "Hello"
 5 
 6 v(myVar) = v(myVar) + 2
 7 str(myVar) =  str(myVar) & " World"
 8 
 9 ' v(myVar) now has the value of 7
10 ' str(myVar) now has the value of "Good Morning"
11 ' Notice how a user variable simultaneously hold a double and a string at the same time. The double side does not interfere with the string side and vice versa.

Note how a user variable simultaneously can hold a double and a string.

Arrays

By clicking Add while holding shift in the variable interface you create a user array. Currently, user arrays can only contain double values. User arrays must first be initialized using the redim function before usage.

' By creating an array called "myArr" in the interface you can... 
' Initialize the array using redim 
' Read documentation on redim for more information on usage 
call redim(0, myArr, ARRAY_LENGHT) 
' Access value of an array at an index 
array(myArr(index))
' === Example call 
redim(0, myArr, 3) 
array(myArr(1)) = 5 
array(myArr(2)) = 7 
array(myArr(3)) = array(myArr(1)) + array(myArr(2)) 
' The array now has the following values of [5, 7, 12]

Dim Variables

Dim variables are a different way of creating and interacting with variables than user variables. A dim variable can only have a single type of data that must be defined on creation. Variable naming standards are the same as user variables, except you may not use the same name of other existing functions and keywords.

' You can initialize a variable 
dim varName as type

' You can initialize a variable with a defined value
dim varName as type = value

'Once initialized you just write the variable name to access it
varName
 1 ' === Example
 2 dim myInt as integer
 3 dim myLng as long
 4 dim myDbl as double = 5
 5 dim myStr as string = "Hello"
 6 
 7 myInt = myDbl*2
 8 myLng = myDbl*5
 9 myStr = myStr & " World"
10 
11 'myInt has the value of 10
12 'myLng has the value of 25
13 'myDbl has the value of 5
14 'myStr has the value of "Hello World"


Expressions

An expression is a line of code that evaluates to an answer. Something as simple as 1 + 1 is an expression. Teascript offers different tools to create diverse expressions that suit what you specifically need.

Operators

Mathematical Operators

Mathematical Symbols
Symbol Name Example
+ Addition
12 + 2 + 3 'returns 17
- Subtraction
12 - 2 - 3 'returns 7
* Multiplication
12*2*5 'returns 120
/ Division
'Note that division by 0 will crash SMBX 
12/2/5 'returns 1.2
\ Division with no remainder
'Note that division by 0 will crash SMBX
12\2\5 'returns 1
^ Power
'Note that 0^0 will return 1
12^2 'returns 144
mod Modulus
'Note that modulating by 0 will crash SMBX
12 mod 5 'returns 2
& Concatenation
"ABC" & ";" & "123" 'returns "ABC;123"
( ) Parenthesis
12*(2 + 5) 'returns 84

Comparing Operators

Note that all comparative operators require both sides use the same data type. (You can compare numbers with other numbers and strings with other strings, but you cannot compare numbers with strings)

Comparitive Operators
Symbol Name Description
= Equal Numbers Returns -1 if both sides are equal, otherwise 0
Strings Returns -1 if both sides are equal, otherwise 0
<> Not equal Numbers Returns -1 if both sides are not equal, otherwise 0
Strings Returns -1 if both sides are not equal, otherwise 0
> Grater than Numbers Returns -1 if the value on the left is larger, otherwise 0
Strings Unknown pattern
< Less than Numbers Returns -1 if the value on the left is smaller, otherwise 0
Strings Unknown pattern
>= Greater than or equal Numbers Returns -1 if the value on the left is larger or equal, otherwise 0
Strings Unknown pattern
<= Less than or equal Numbers Returns -1 if the value on the left is smaller or equal, otherwise 0
Strings Unknown pattern
like Like Numbers Not compatible
Strings https://docs.microsoft.com/en-us/dotnet/visual-basic/language-reference/operators/like-operator

Logical Operators

Logical operators only work on numbers. They are commonly used with -1 and 0 to represent true and false respectively. Other numbers can be used but it may yield different patterns.

Logical Operators
P Q not P P and Q P or Q P xor Q P eqv Q P imp Q
0 0 -1 0 0 0 -1 -1
0 -1 -1 0 -1 -1 0 -1
-1 0 0 0 -1 -1 0 0
-1 -1 0 -1 -1 0 -1 -1


Special Values

These special values behave like numbers.

Special Values
Name Value
pi 3.141592654
e 2.71828182
rnd A random number between 0 and 1. The value changes every time the variable is accessed.

Built-in Functions

Functions are powerful tools that allow you to simplify and expand the flexibility of your scripts. To access a function, you write the function name and in parenthesis write the parameters separated by commas. You can put functions inside an expression just as it were a regular number or string.

myFunc(param1, param2, ..., paramN)
1 ' === Example
2 dim x as integer = -5
3 dim y as integer
4 y = abs(x) + 1  
5 ' x returns -5; y returns 6
6 ' Note how the abs() function is used

These are the the mathematical functions provided in TeaScript.

Parameters can be numbers, strings, and arrays.

Functions
Name and Parameters Return Type Description and Example
abs(x) Number Returns the absolute value of a number
abs(-3) 'returns 3
exp(x) Number Returns the number to the power of the e constant
exp(5) 'returns e^5
log(x) Number Returns the log of the number with a base of e
log(e) 'returns 1
sgn(x) Number Returns the sign of the number (1, -1, or 0)
sgn(10)  'returns 1
sgn(0)   'returns 0
sgn(-10) 'returns -1
int(x) Number Returns the number rounded up. Similar to the common ceiling function
int(2.1) 'returns 3
fix(x) Number Returns the number rounded down. Similar to the common floor function
fix(2.9) 'returns 2
sqr(x) Number Returns the square root of a number
sqr(9) 'returns 3
sin(x) Number Returns the sine of the number. Uses radians
sin(pi) 'returns 0
cos(x) Number Returns the cosine of the number. Uses radians
cos(pi) 'returns 1
tan(x) Number Returns the tangent of the number Uses radians
tan(pi/4) 'returns 1
atn(x) Number Returns the inverse tangent of the number. Uses radians
atn(1) 'returns pi/4
getangle(x, y) Number Returns the angle (from 0 to 1) formed between the triangle. Similar to the common atan2 function.
getangle(1, 0)  'returns 0
getangle(1, 1)  'returns .125
getangle(0, 1)  'returns .25
getangle(-1, 0) 'returns 0.5
getangle(0, -1) 'returns 0.75
rgba(red, green, blue, alpha) Number Returns an SMBX color value. Parameters must be between 0 and 255
rgba(255, 255, 255, 255) 'returns -1
round(x, decimal place) Number Returns the number rounded
round(1.3456, 2) 'returns 1.35
len(txt) Number Returns the length of the text
 len("ABC") 'returns 3
left(txt, len) String Returns the text cropped from the string inputted. The crop begins from the start and ends with the length specified.
left("Hello", 2) ' Returns "He"
right(txt, len) String Returns the text cropped from the string inputted. The crop ends from the end and begins with the length specified.
right("Hello", 3) ' Returns "llo"
mid(txt, start, len) String Returns the text cropped at the specified start and has the specified length provided.
mid("Hello", 2, 3) ' Returns "ell"
replace("txt", "search", "replacement", #start, #count, #case_insensitive) String Replaces a part of the text with a new one.


start Where in the txt should the search start
count The number of replacements. Set to -1 to disable
case_insensitive Set to 1 to make the search case-insensitive, otherwise use 0

asc(char) Double Returns the ANSI code. It will use the first character if more than one is passed
chr(code) String Returns a string using the ANSI code. Accepts 0-255
ascw(char") Double Returns the unicode code. It will use the first character if more than one is passed
chrw(code) String Returns a string using the unicode code. Accepts 0-65535
cstr(num) String Converts the number to a string
cdbl(txt) Double Converts the string into a number
instr(start, txt, search) Double To return the point of the first appearance of a given string in another string.


start To specify the start point of the search
string1 The original string
string2 The string to be searched

ubound(array) Number Returns the length of the array
call redim(0, myArr, 3)
ubound(myArr) ' Returns 3

Control Flow

When a script is run in TeaScript it will start reading the script from top to bottom, left to right. It will read and execute the code in that order. the following is a list of ways to customize and manipulate what code gets executed in your scripts.

Conditions

Conditions represent "true" and "false". In Teascript -1 and 0 represents true and false. Any number that is not 0 may also represent true, but use -1 and 0 for consistency reasons.

 1 -1  ' Represents True
 2 0   ' Represents False
 3 5   ' Represents True (because non-zero numbers represent true)
 4 
 5 dim w as integer = -1
 6 dim x as integer = 5
 7 dim y as integer = 5
 8 dim z as integer = 0
 9 
10 w    ' Represents True (because w has the value of -1)
11 x    ' Represents True (because x has a value of a non-zero number)
12 y    ' Represents True (because y has a value of a non-zero number)
13 z    ' Represents False (because z has a value of 0)
14 
15 z - 1    ' Represent True (because 0 - 1 = -1)
16 w + 1    ' Represent False (because -1 + 1 = 0)
17 
18 ' Using logical operators 
19 not w          ' Represent False
20 not (y and z)  ' Represents True
21 w or z         ' Represents True

If Statements

The if statement is a basic but useful statement. It has one parameter being a condition.

' Basic if statement
if conditon then
  statement
end if

' Shortcut if statement
if condition then statement

' If statement using one elseif and an else statement
if conditon then
  statement
elseif condition then
  statement
...    ' You can have as many elseif as you want 
else
  statement
end if

When TeaScript reads an if statement it will check each condition from top to bottom until it reaches a condition that is true. When it reaches a condition that is true, it will execute the statements inside and continue the code after the entire if statement. This means that conditions written on the top will have priority over those conditions in the bottom.

The else is special since it does not require any conditions. An else must be written in the bottom after all other elseif statements (if there are any). The code inside the else will only run if every other condition in the if and elseif statements evaluated to false.

' === Example
dim x as integer = 0
dim y as integer = -1
dim z as integer = -1

' Since (x and y) evaluates to 0, this statement is not run.
if x and y then z = 0

' Since (x and z) evaluates to 0, this statement is not run.
if x and z then
  y = 0

' Since (y) evaluates to -1, this statement is run.
elseif y then
  x = -1

' Since the previous elseif has priority and only one statement can be run, this statement is not run
else
  z = -1
end if

Select Case

Select Case lets you easily organize the control flow based on a value. It has one parameter being a value.

select case value
  case -1
    statement ' Will run if value is exactly -1
  case 0 to 1
    statement ' Will run if value is between (inclusive) 0 and 1
  case is < -1
    statement ' Will run if value is less than negative one
  case 2, 3, 4
    statement ' Will run if value is exactly 2, 3 or 4
  case "example"
    statement ' Will run if value is exactly "example".
  case else
    statement ' Will run if value does not match any of the other conditions
end select

Select case at its core is similar to various if statements and behaves similarly to the common "switch" statement in other languages. It will read the value that is passed and executes the first code in which the value matches. It will read the cases from top to bottom giving priority to cases at the top.

The to keyword can be used when checking for a case.

  • Numbers Will be true if the value is between (inclusive) the two numbers provided.
  • Strings Unknown pattern

The is keyword can be used to make comparisons to the value. It can be used with the <, >, <=, or >= logical operators.

You can use commas to check for multiple cases at once. The commas behave similarly to an or logical operator. The case will go through if it matches with any of the cases.

With Statements

With statements are useful to read or write on multiple properties of an object. An object can be for example an NPC, Block, or BGO. Check the classes section for more information on SMBX Objects. You can acess all of the properties by typing a . followed by the property name.

with object
  .property_name
end with


' === Example
with NPC(1)
  .x = 12345
  .y = 54321
  .forecolor = rgba(10, 60, 60, 255)
  v(myVar) = .ysp
end with

' This is equivalent to:
  NPC(1).x = 12345
  NPC(1).y = 54321
  NPC(1).forecolor = rgba(10, 60, 60, 255)
  v(myVar) = NPC(1).ysp

Goto

Using goto will force the script to jump to a specific line using a label.

Example:
[statements]
goto Example

When the script reached "goto Example" it will jump to "Example" and execute the script below it. The labels used with goto statements must: have names that do not contain characters that do not follow variable name rules, there must not be two labels with the same name and there should not be goto statements inside "with" statements either (meaning you can't use them when scripting an npc).

GoSub

Gosub statements are very similar to goto ones, but there is a noticeable difference.

mysub1:
[statement 1]
gosub mysub1
return

mysub2:
[statement 2]
gosub mysub2
return

While goto statements will simply jump into a given line, gosub statement can keep track of where it came from. This means the program won't search through the whole stack to find a given label, instead it will do from the last "return" found. Gosub statements must follow the same rules as goto statements.

Loops

It is important to note that you should avoid an infinite loop. Make sure to either have a "sleep" function (if the script was called by an event) or an "exit" if you set up a for loop to go indefinitely.

Pure

A pure loop is a very simple and basic form of a loop.

'Pure loop:
do
  'Code that will be executed multiple times
loop

The loop will run indefinitely.

While

The game will repeat executing statements inside do statement until condition returns true. The condition be checked at the beginning or either at the end of the loop.

In this example the game checks the condition at the beginning, meaning if condition is false the game won't execute statements inside "do".

do while condition
  [statement]
loop

In this example the condition is checked at the end of the loop. This means that is condition is false the game will execute anyway statements inside "do" until it reaches "while" and verify the condition.

do
  [statement]
loop while condition

Until

The game will repeat executing statements inside do statement until condition returns false. You can also make the game check the condition at the beginning or at the end of the loop like with "while" statements.

do until condition
  'Code that will be executed multiple times
loop

do
  'Code that will be executed multiple times
loop until condition

For

A "for" loop is a loop that will run a certain amount of times. It has three parameters: "initial_value", "ending_value", and "setp_value".

for v(myCounter) = initial_value to ending_value step step_value
  'code that will be executed multiple times
next

'step_value is optional and if omitted the loop will behave with a step of 1
for v(myCounter) = initial_value to ending_value
  'code that will be executed multiple times
next

An already existing variable must be set to "initial_value". The variable will start the loop with this and increment by the value set in "step_value". You can still manipulate the variable while inside the "for loop".

The loop will continue going until the variable is larger or equal to "ending_value" when the script reaches "next". The loop will also stop if the variable is less than the "initial value" when it reaches next. Once the loop stops it will continue reading the script.

When TeaScript reads an "exit for" while inside a "for loop" it will immediately skip to the next keyword and resume the script.

Exit

An exit will terminate a loop and skip the code after it until it reaches the "loop" or "next" keyword (Depending on what loop it was used on).

'This will work while inside a pure, while, or until loop
exit do

'This will work while inside a for loop
exit for

'This will force the game to stop immediately executing the script
exit script

Script

Using the script keyword, it allows you to make useful custom functions and procedures in Teascript.

v(myvar) = exampleWithReturn(5, "test")
call exampleWithNoReturn()

'A script set up as a function (has a return)
script exampleWithReturn(myDoubleParam as double, myStringParam as string, return double)
  return param(myDoubleParam) + len(strparam(myStringParam))
end script

'A script set up as a procedure (has no return)
script exampleWithNoReturn()
  v(myVar) = v(myVar)*2
end script

When setting up a script, all parameters must be defined by name and type as shown below. You may have as many parameters as needed. Note that return is optional. All script and parameter naming standards are similar to variable naming standards with one exception. Script names must not contain numbers.

script example(name as type, name as type, ..., return type)
  param(name)     'Use param when reading the value of a double
  strparam(name)  'Use strparam when reading the value of a string
end script

Unlike common functions in other languages, TeaScript cannot do the following:

  • Set the value of passed down parameters. All parameters passed down are read-only.
  • Create recursive scripts. You cannot call a script within itself.

The "return" keyword will only in functions. If a function has no return, then it will return 0 or "" (based on the return type that was specified. SMBX will error if you include a return in a procedure.

It is important to note that when called, procedures must have the "call" keyword. This also applies to a function if you do not read the returned value.

Oddities and Quirks

The following is a list of oddities that you may experience when using TeaScript

Negatives to a Non-Integer Power

sqr(x) is equivalent to x^(0.5). Therefore (-1)^(0.5) results in a complex number with a imaginary component. Teascript does not offer complex numbers in its data types.

dim x as integer = -1
dim y as integer

y = (-1)^(0.5) ' This returns an error when run.
y = x^(0.5)    ' This does not error but will evaluate to 0

Writing Double Quotation Marks

Since double quotation marks are reserved for defining string, you must use chr or chrW to write a double quotation mark inside a string.

str(myVar1) = chrW(34) '34 is the ID of the double quotation marks. (ID 34 works too in chr() too)

'You can define a variable as a quotation mark or call the quotation mark directly, both work the same
str(myVar2) = "These are some "&str(myVar1)&"special"&chrW(34)&" marks"

'str(myVar2) is "These are some "special" marks"

> THESE PROBLEMS ARE FIXED in 1.4.5 <

Writing Decimal Numbers
When writing decimal number, you must include a number before the decimal point.

'Wrong
v(myVar) = .1

'Correct
v(myVar) = 0.1


Writing negative numbers
When writing a negative number, make sure there are no other symbols beforehand (except parenthesis).

'Wrong (Teascript errors due to seeing * and - next to each other)
v(myVar) = 5*-4

'Correct
v(myVar) = 5*(-4)
v(myVar) = -4*5