Visual Prolog Language Support

Full language support for Visual Prolog 5.2 in Visual Studio Code, including syntax highlighting, code snippets, and IntelliSense features.

Features

🎨 Comprehensive Syntax Highlighting

• Directives: domains, predicates, clauses, goal, facts, database, constants
• Class/Object-Oriented Keywords: class, object, interface, implement, end class, end object
• Control Flow: if, then, else, elseif, not, fail, true, and, or, repeat, cut
• Modifiers: determ, nondeterm, multi, procedure, single, static, abstract, virtual, override, final
• Built-in Types: char, byte, short, ushort, word, integer, unsigned, long, ulong, dword, real, real4, real8, string, symbol, pointer, binary, file
• Built-in Predicates: write, read, assert, retract, findall, member, append, concat, and many more
• Operators: Arithmetic (+, -, *, /, mod, div), Comparison (=, <>, <, >, <=, >=), Logical (and, or, not), Bitwise (shl, shr, xor)

📝 Smart Code Snippets

Type the prefix and press Tab to expand:

Program Structure Snippets

program - Full program template

% Program Name
% Description

domains
    DomainName = type

predicates
    predicateName(arguments)

clauses
    predicateName(Args) :-
        body.

goal
    predicateName(actualArgs).

domain - Domain declaration

domains
    DomainName = type

predicate - Predicate declaration

predicates
    predicateName(arguments)

clause - Clause definition

clauses
    predicateName(Args) :-
        body.

goal - Goal section

goal
    goalPredicate.

Object-Oriented Snippets

class - Class declaration

class ClassName
predicates
    predicateName(arguments)
clauses
    predicateName(Args) :-
        body.
end class ClassName

interface - Interface declaration

interface InterfaceName
predicates
    predicateName(arguments)
end interface InterfaceName

implement - Implementation section

implement ClassName
clauses
    predicateName(Args) :-
        body.
end implement ClassName

Control Flow Snippets

if - If-then-else statement

if condition then
    thenBody
else
    elseBody
end if

determ - Deterministic predicate

predicates
    determ predicateName(arguments)

nondeterm - Non-deterministic predicate

predicates
    nondeterm predicateName(arguments)

Database Operations Snippets

database - Database section

database
    databaseName
predicates
    predicateName(arguments)

fact - Fact declaration

facts
    factName(arguments)

assert - Assert clause

assert(fact)

retract - Retract clause

retract(fact)

findall - Find all solutions

findall(Template, Goal, ResultList)

I/O and Built-in Predicates

write - Write output

write(output)

read - Read input

read(variable)

openread - Open file for reading

openread(FileName, FileHandle)

openwrite - Open file for writing

openwrite(FileName, FileHandle)

List Operations

list - List pattern

[Head|Tail]

member - Member check

member(Element, List)

append - Append lists

append(List1, List2, Result)

String Operations

concat - String concatenation

concat(String1, String2, Result)

🔧 Editor Features

• Auto-closing pairs: Automatically closes (), [], {}, and ""
• Comment toggling: Use Cmd+/ (macOS) or Ctrl+/ (Windows/Linux) to toggle line comments (%)
• Block comments: Select code and use comment shortcut for multi-line comments (/* */)
• Bracket matching: Highlights matching brackets, parentheses, and braces
• Smart indentation: Proper indentation for Visual Prolog code structure

🎯 Naming Conventions Support

• Types/Domains: Names starting with uppercase letters are highlighted as types (e.g., Person, StudentList)
• Predicates/Functions: Names starting with lowercase letters are highlighted as predicates (e.g., factorial, processData)
• Variables: Uppercase identifiers in code are recognized as variables
• Atoms: Lowercase identifiers are recognized as atoms/constants

Supported File Extensions

• .pro - Visual Prolog program files
• .cl - Clause files
• .pack - Package files
• .ph - Prolog header files

Usage Examples

Example 1: Simple Factorial Program

Type program and Tab to get the template, then modify:

% Factorial Calculator
% Calculates factorial of a number

domains
    Number = integer

predicates
    factorial(Number, Number)

clauses
    factorial(0, 1) :- !.
    factorial(N, Result) :-
        N > 0,
        N1 = N - 1,
        factorial(N1, R1),
        Result = N * R1.

goal
    factorial(5, X),
    write("Factorial of 5 is: ", X),
    nl.

Example 2: List Operations

% List Processing Example

domains
    IntList = integer*

predicates
    sumList(IntList, integer)
    member(integer, IntList)

clauses
    sumList([], 0).
    sumList([H|T], Sum) :-
        sumList(T, RestSum),
        Sum = H + RestSum.
    
    member(X, [X|_]).
    member(X, [_|T]) :-
        member(X, T).

goal
    List = [1, 2, 3, 4, 5],
    sumList(List, Total),
    write("Sum: ", Total), nl.

Example 3: Class-Based Programming

Type class and Tab:

class Student
domains
    Name = string
    Age = integer
    
predicates
    create(Name, Age)
    displayInfo()
    
clauses
    StudentName : Name
    StudentAge : Age
    
    create(N, A) :-
        StudentName := N,
        StudentAge := A.
    
    displayInfo() :-
        write("Name: ", StudentName), nl,
        write("Age: ", StudentAge), nl.
end class Student

goal
    S = Student::new(),
    S:create("John Doe", 20),
    S:displayInfo().

Example 4: Database Operations

Type database and Tab:

database
    phoneBook

predicates
    nondeterm phone(string, string)
    addPhone(string, string)
    findPhone(string)

clauses
    addPhone(Name, Number) :-
        assertz(phone(Name, Number)).
    
    findPhone(Name) :-
        phone(Name, Number),
        write(Name, ": ", Number), nl,
        fail.
    findPhone(_).

goal
    addPhone("Alice", "555-1234"),
    addPhone("Bob", "555-5678"),
    findPhone("Alice").

Requirements

• Visual Studio Code version 1.50.0 or higher
• Visual Prolog 5.2 compiler (for running programs)

Installation

From VSIX File

1. Download the .vsix file
2. Open VS Code
3. Go to Extensions (Cmd+Shift+X or Ctrl+Shift+X)
4. Click on the ... menu at the top
5. Select "Install from VSIX..."
6. Choose the downloaded file

From Source

1. Clone or download this repository
2. Copy the folder to your VS Code extensions directory:
   • Windows: %USERPROFILE%\.vscode\extensions
   • macOS/Linux: ~/.vscode/extensions
3. Restart VS Code

Tips and Tricks

Quick Snippet Access

• Type the snippet prefix and press Tab to expand
• Use Ctrl+Space to see all available snippets for Visual Prolog

Code Navigation

• Cmd+Shift+O (macOS) or Ctrl+Shift+O (Windows/Linux) - Go to symbol in file
• F12 - Go to definition (when supported by workspace indexing)

Commenting

• Cmd+/ or Ctrl+/ - Toggle line comment (%)
• Shift+Option+A (macOS) or Shift+Alt+A (Windows/Linux) - Toggle block comment (/* */)

Multi-Cursor Editing

• Option+Click (macOS) or Alt+Click (Windows/Linux) - Add cursor
• Useful for editing multiple similar predicates at once

Known Issues

• Semantic analysis and IntelliSense are limited to syntax highlighting
• Go to Definition requires manual workspace symbol indexing
• No integrated compiler/debugger (use external Visual Prolog tools)

Release Notes

0.1.0

Initial release of Visual Prolog Language Support:

• Complete syntax highlighting for Visual Prolog 5.2
• 25+ code snippets for common patterns
• Auto-closing pairs and bracket matching
• Support for .pro, .cl, .pack, and .ph files
• Comment toggling with standard VS Code shortcuts

Contributing

Found a bug or have a feature request? Please open an issue on the repository.

License

MIT License - see LICENSE file for details

Resources

• Visual Prolog Official Website
• Visual Prolog Documentation
• Repository

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Enjoy coding in Visual Prolog! 🚀