Blingo_vs_CSharp.md

Lingo vs C# Differences

The tables below summarize how BlingoEngine converts Lingo syntax into C#.

Blingo‑specific constructs

Lingo example	C# equivalent
-- comment	// comment
on handler a, b … end	void Handler(type a, type b) { … }
global gVar	GlobalVars singleton injected via DI
property myValue	class field/property
me	this
void	null
sprite(n).locH	Sprite(n).LocH
sprite(n).member = member("Name")	Sprite(n).SetMember("Name");
member("Name").text	Member<BlingoMemberText>("Name").Text
the mouseH	_Mouse.MouseH
the actorList.append(me)	_Movie.ActorList.Add(this)
script("Class").new(args)	new Class(args)
sendSprite 2, #doIt	SendSprite<B2>(2, b2 => b2.doIt());
myMovieHandler	CallMovieScript<M1>(m1 => m1.myMovieHandler());

Classic control flow

Lingo example	C# equivalent
repeat with i = 1 to n	for (int i = 1; i <= n; i++)
repeat with item in list	foreach (var item in list)
repeat while cond	while (cond)
repeat until cond	do { … } while (!cond)
repeat forever	while (true)
exit repeat	break;
exit repeat if cond	if (cond) break;
next repeat	continue;
next repeat if cond	if (cond) continue;
if a > b then … end if	if (a > b) { … }
case v of … end case	switch (v) { … }
exit	return;
[1,2,3]	new[] { 1, 2, 3 }
"A" & "B"	"A" + "B"
<> (not equal)	!=
voidp(x)	x == null

Additional notes:

• Lingo lists and collections are 1‑based, whereas C# arrays and lists are 0‑based.
• Lingo requires then and end if around conditionals; C# uses curly braces.
• To access text members, use the generic Member<T> helper, e.g. member("Name").text becomes Member<BlingoMemberText>("Name").Text.

Constructors and IoC

Lingo scripts are instantiated at runtime using the script("Class").new(args) syntax. When converted to C#, each script becomes a class whose constructor can accept dependencies. The engine resolves these dependencies through the dependency injection container when the script is created.

// Example parent script
public class BlockParent : BlingoParentScript
{
    private readonly GlobalVars _global;

    // IBlingoMovieEnvironment is provided by the runtime; GlobalVars comes
    // from the service container
    public BlockParent(IBlingoMovieEnvironment env, GlobalVars global)
        : base(env)
    {
        _global = global;
    }
}

Scripts are registered with the container using helpers such as AddScriptsFromAssembly() or AddMovieScript<T>(). When Lingo code executes new(script "Block"), BlingoEngine retrieves the constructor from the container and supplies any required services automatically.

Creating Cast Members

In Lingo you create new members using the newMember command. The type symbol indicates what kind of member to create.

-- create a new bitmap cast member
newBitmap = _movie.newMember(#bitmap)
newBitmap.name = "Background"

In C#, use the New factory on IBlingoMovie to create typed members:

// equivalent to the Lingo example above
var newBitmap = _movie.New.Bitmap(name: "Background");

The factory exposes helper methods for each member type, such as Bitmap(), Sound(), FilmLoop() and Text(). Optional arguments let you specify the cast slot or member name.

🔁 put ... into ... Handling in C#

Lingo's put syntax is used for assignment across a wide range of targets:

put "Hello" into field "Status"
put 100 into sprite(3).locH
put 42 into myList[2]

In Lingo, if the target does not exist (e.g., a missing field), it fails silently.
To match that behavior in C#, BlingoEngine introduces safe assignment helpers.

✅ C# Equivalents

Lingo	C#
put 100 into x	x = 100;
put "Hi" into field "Greeting"	PutTextIntoField("Greeting", "Hi");
put 100 into sprite(3).locH	Sprite(3).LocH = 100;
put 42 into myList[2]	myList.SetAt(2, 42);

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✳️ Safe Field Assignment: PutTextIntoField()

PutTextIntoField("Greeting", "Hello");

This method attempts to locate a field member and assign the text, but does nothing if the field is missing, just like Lingo.

Method:

protected void PutTextIntoField(string name, string text)
{
    TryMember<IBlingoMemberField>(name, field => field.Text = text);
}

---

⚠️ Avoiding Exceptions with TryMember<T>()

To safely access any member (e.g., bitmap, field, text), use the Action<T> overload:

TryMember<IBlingoMemberText>("Title", m => m.Text = "Welcome");

This form avoids explicit null checks and keeps the call concise.

TryMember overloads available:

TryMember<T>(string name, int? castLib = null, Action<T>? action = null)

This method:

• Returns null if the member is not found
• Executes the action if the member exists

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🧱 Building Custom Safe put Functions

You can create safe helpers for other member types, e.g.:

protected void PutSoundInto(string name, IBlingoSoundData sound)
{
    TryMember<IBlingoMemberSound>(name, m => m.Sound = sound);
}

---

🔍 Summary

Pattern	Use
Direct assignment	For local variables or known safe references
PutTextIntoField(name, value)	For field text, silent on failure
TryMember<T>(..., action)	For concise safe access to members
SafePut<T>() (optional)	For generalized logic via delegates

This ensures Lingo compatibility without throwing exceptions and keeps behavior fail-safe, just like in Director.