Andrew Branscom: /* Action Commands */

2025-09-20T22:41:26Z

Action Commands

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	<div class="CodeBlockHeader">Code:</div>		<div class="CodeBlockHeader">Code:</div>
	<syntaxhighlight lang="c#">		<syntaxhighlight lang="agi">
	assign.v(v50,0);		assign.v(v50,0);

Andrew Branscom: /* Action Commands */

2025-09-20T22:40:59Z

Action Commands

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	assign.v(v50,0);		assign.v(v50,0);

Andrew Branscom at 00:09, 2 April 2025

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	This article describes the '''logic syntax''' for the C-like "official" AGI syntax described in the [[Adventure Game Interpreter Specifications\|AGI Specifications]] and supported by [[~~agiw:~~AGI Studio\|AGI Studio]] and [[~~agiw:~~WinAGI\|WinAGI]].		This article describes the '''logic syntax''' for the C-like "official" AGI syntax described in the [[Adventure Game Interpreter Specifications\|AGI Specifications]] and supported by [[AGI Studio\|AGI Studio]] and [[WinAGI\|WinAGI]].
	<!--		<!--
	'''Note:''' The [[~~agiw:~~WinAGI\|WinAGI]] development environment supports an [[VB Logic Syntax\|alternate syntax]], that is based on Microsoft's Visual Basic language, rather than the C language. At this time, the C-based syntax described in this article is the most widely-supported AGI logic syntax. -->		'''Note:''' The [[WinAGI\|WinAGI]] development environment supports an [[VB Logic Syntax\|alternate syntax]], that is based on Microsoft's Visual Basic language, rather than the C language. At this time, the C-based syntax described in this article is the most widely-supported AGI logic syntax. -->

	==<br /> Action Commands ==		==<br /> Action Commands ==

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[[Category:AGI Pages]]
<div align="center"><span style="font-size: 22pt">Logic Syntax</span></div>

 

This article describes the '''logic syntax''' for the C-like "official" AGI syntax described in the [[Adventure Game Interpreter Specifications|AGI Specifications]] and supported by [[agiw:AGI Studio|AGI Studio]] and [[agiw:WinAGI|WinAGI]].


==<br /> Action Commands ==

Normal action commands are specified by the command name followed by parentheses which contain the arguments, separated by commas. A semicolon is placed after the parentheses. The parentheses are required even if there are no arguments. The arguments given must have the correct prefix for that type of argument as explained later in this document (this is to make sure the programmer does not use a [[Variable (AGI)|variable]], for example, when they think they are using a [[Flag (AGI)|flag]]).

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
assign.v(v50,0);

program.control();
</syntaxhighlight>

Multiple commands may be placed on the one line:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
reset(f6); reset(f7);
</syntaxhighlight>

Substitutions for the following action commands are available:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
increment(v30); v30++;
decrement(v30); v30--;
assignn(v30,4); v30 = 4;
assignv(v30,v32); v30 = v32;
addn(v30,4); v30 = v30 + 4; or v30 += 4;
addv(v30,v32); v30 = v30 + v32; or v30 += v32;
subn(v30,4); v30 = v30 - 4; or v30 -= 4;
subv(v30,v32); v30 = v30 - v32; or v30 -= v32;
mul.n(v30,4); v30 = v30 * 4; or v30 *= 4;
mul.v(v30,v32); v30 = v30 * v32; or v30 *= v32;
div.n(v30,4); v30 = v30 / 4; or v30 /= 4;
div.v(v30,v32); v30 = v30 / v32; or v30 /= v32;

lindirectn(v30,4); *v30 = 4;
lindirectv(v30,v32); *v30 = v32;
rindirect(v30,v32); v30 = *v32;
</syntaxhighlight>

==<br /> If structures and test commands ==

An if structure looks like this:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (test commands) {
action commands
}
</syntaxhighlight>

or like this

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (test commands) {
action commands
}
else {
more action commands
}
</syntaxhighlight>

Carriage returns are not necessary:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (test commands) { action Commands } else { more action commands }
</syntaxhighlight>

Test commands are coded like action commands except there is no semicolon. They are separated by <code>&&</code> or <code>||</code> for AND and OR, respectively:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (isset(f5) &&
greatern(v5,6)) { ......
</syntaxhighlight>

Again, carriage returns are not necessary within the if statement:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (lessn(v5,6) && (greatern(v5,2)) { .......

if (isset(f90) && equalv(v32,v34) &&
greatern(v34,20)) { .......
</syntaxhighlight>

A ! placed in front of a command signifies a NOT.

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (!isset(f7)) {
......
</syntaxhighlight>

Boolean expressions are not necessarily simplified so they must follow the rules set down by the file format. If test commands are to be ORred together, they must be placed in brackets.

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if ((isset(f1) || isset(f2)) {
......

if (isset(f1) && (isset(f2) || isset(f3))) {
......

if (isset(1) || (isset(2) && isset(3))) { is NOT legal
</syntaxhighlight>

Depending on the compiler, simplification of boolean expressions may be supported, so the above may not apply in all cases (although if these are rules are followed then the logic will work with all compilers).

Substitutions for the following test commands are available:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
equaln(v30,4) v30 == 4
equalv(v30,v32) v30 == v32
greatern(v30,4) v30 4
greaterv(v30,v32) v30 v32
lessn(v30,4) v30 4
lessv(v30,v32) v30 v32
!equaln(v30,4) v30 != 4
!equalv(v30,v32) v30 != v32
!greatern(v30,4) v30 = 4
!greaterv(v30,v32) v30 = v32
!lessn(v30,4) v30 = 4
!lessv(v30,v32) v30 = v32
</syntaxhighlight>

Also, flags can be tested for by just using the name of the flag:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (f6) { .....

if (v7 > 0 && !f6) { .....
</syntaxhighlight>

which is equivalent to:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (isset(f6)) { .....

if (v7 > 0 && !isset(f6)) { .....
</syntaxhighlight>

==<br /> Argument types ==

There are 9 different types of arguments that commands use:

{| border="1" cellpadding="5"
! Type!! Prefix
|-
| Number|| (no prefix)
|-
|[[Variable (AGI)|Variable]]||v
|-
|[[Flag (AGI)|Flag]]|| f
|-
|[[Message (AGI)|Message]]|| m
|-
|[[AGI Animated Object|Object]]|| o
|-
|[[Inventory Item (AGI)|Inventory Item]]|| i
|-
|[[String (AGI)|String]]|| s
|-
|[[Word (AGI)|Word]]|| w
|-
|[[Controllers (AGI)|Controller]]|| c
|}

The [[Said|said]] test command uses its own special arguments which will be described later.

Each of these types of arguments is given by the prefix and then a number from 0-255, e.g. <code>v5</code>, <code>f6</code>, <code>m27</code>, <code>o2</code>.

The word type represents words that the player has typed in (as opposed to words that are stored in the [[WORDS.TOK|WORDS.TOK]] file). Strings are the temporary string variables stored in memory, not to be confused with messages (that are stored in the logic resources). Controllers are menu items and keys.

Compilers can enforce type checking, so that the programmer must use the correct prefix for an argument so that they know they are using the right type. Decoders should display arguments with the right type.

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
move.obj(o4, 80, 120, 2, f66);

if (obj.in.box(o2, 30, 60, 120, 40)) { .....
</syntaxhighlight>

For a complete list of the commands and their argument types, see [[AGI Logic Commands by Name|Logic commands by name]].

Messages and inventory items may be given in either numerical or text format:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
print("He's not here.");

print(m12);

if (has("Jetpack")) { .....

if (has(i9)) { .....

</syntaxhighlight>

Messages can also be split over multiple lines:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
print("This message is split "
"over multiple lines.");
</syntaxhighlight>

Quote marks must be used around messages and inventory item names. This is important because some messages or inventory item names may contain parentheses or commas, which could confuse the compiler. This is also the case for the said command which will be described shortly.

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (has("Buckazoid(s)")) { ..... // no ambiguity here about where
// the argument ends
</syntaxhighlight>

If quote marks are part of the message or inventory object, a \ should be placed in front of these. To use a \, \\ should be used. \n can also be used for a new line.

The said test command uses different parameters to all the other commands. Where as the others use 8 bit arguments (0-255), said takes 16 bit arguments (0-65535). Also, the number of arguments in a said command can vary. The numbers given in the arguments are the word group numbers from the WORDS.TOK file.

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (said(4, 80)) { .....
</syntaxhighlight>

Words can also be given in place of the numbers:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
if (said("look")) { .....

if (said("open","door")) { .....
</syntaxhighlight>

Quote marks must also be used around the words.

== <br />Labels and the <code>goto</code> command ==

Labels are given like this:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
Label1:
</syntaxhighlight>

The label name can contain letters, numbers, and the characters '_' and '.'. No spaces are allowed.

The [[AGI goto|goto]] command takes on parameter, the name of a label:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
goto(Label1);
</syntaxhighlight>

== Comments ==

There are three ways that comments can be used.

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
// - rest of line is ignored

[ - rest of line is ignored

/* Text between these are ignored */
</syntaxhighlight>
The /*...*/ can be nested:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
/* comment start

print("Hello"); // won't be run

/* // a new comment start (will be ignored!)

v32 = 15; // won't be run

*/ // uncomments the most inner comment

print("Hey!"); // won't be run, still inside comments

*/ // uncomments
</syntaxhighlight>

'''Note:''' the fact that these comments can be nested is very different from almost every other language that uses these types of comments, including C, C , and Java.

==<br /> Defines ==

See [[Defines (AGI)|Defines]].

==<br /> Including files ==

See [[AGI Includes|Includes]].

==<br /> More on messages ==

In some cases you may want to assign a specific number to a message so you can refer to it in other places. This is done by using the #message command, followed by the number of the message then the message itself:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
#message 4 "You can't do that now."
</syntaxhighlight>

Then you can give the message number as the parameter in commands:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
print(m4);
</syntaxhighlight>

Or embed the message in commands as normal and the number you assigned to it before will be used:

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
print("You can't do that now.");
</syntaxhighlight>

<nowiki>#message can be used anywhere in the file, so you do not have to set the message before you use it.</nowiki>

For more details, see [[Message (AGI)|Message]].

==<br /> The <code>return</code> command ==

The [[AGI Return|return]] command is just a normal action command (command number 0), with no arguments. This must be the last command in every [[AGI Logic Resource|logic resource]].

==<br /> See also ==

* [[AGI Logic Language Reference]]

==<br /> Sources ==

* [[AGI Studio Help File]]

==<br /> References ==

<references />

==<br /> Also See ==

*

 

[[Category:Technical Info]]
[[Category:References]]
[[Category:AGI References]]
[[Category:AGI Logic]]
[[Category:AGI Variables]]
[[Category:AGI Syntax]]

AGI Logic Syntax - Revision history

Andrew Branscom: /* Action Commands */

Andrew Branscom: /* Action Commands */

Andrew Branscom at 00:09, 2 April 2025

Andrew Branscom: 2 revisions imported

Andrew Branscom: 1 revision imported

sierraw>Andrew Branscom at 01:28, 7 February 2022