LanguageWorkbench

LanguageWorkbench is a .NET 10 learning project for building a language-processing pipeline. It currently scans, parses, and interprets a growing Pascal subset while exposing the intermediate code and symbol-table data used between stages.

Status

The Pascal lexical scanner supports reserved words, identifiers, integer and real literals, string literals, comments, and Pascal special symbols. The active top-down parser builds intermediate code for compound statements, assignments, expressions, IF, REPEAT, WHILE, FOR, and CASE statements. The interpreter evaluates expressions and executes those control-flow constructs.

The bottom-up parser remains experimental and is not selected by the CLI. Instruction generation for compile is intentionally still a placeholder.

Projects

Project	Responsibility
src/LanguageWorkbench.Cli	Command-line entry point and console listeners.
src/FrontEnd	Source reader, scanner, tokens, parser abstractions, and Pascal front end.
src/Intermediate	Intermediate-code and symbol-table contracts.
src/BackEnd	Intermediate-code interpreter and placeholder instruction generator.
src/Messaging	In-process producer/listener messaging infrastructure.

Requirements

• .NET SDK 10.0 or later

Build

dotnet build LanguageWorkbench.sln

Run

The CLI accepts compile and execute operations followed by a Pascal source-file path.

dotnet run --project src/LanguageWorkbench.Cli -- compile -i src/LanguageWorkbench.Cli/repeat.pas
dotnet run --project src/LanguageWorkbench.Cli -- execute src/LanguageWorkbench.Cli/repeat.pas

Flags can be combined:

• -i: print intermediate code.
• -x: print the symbol-table cross-reference.

Set LANGUAGE_WORKBENCH_SHOW_TOKENS=true (or 1) to include token output. Set LANGUAGE_WORKBENCH_OUTPUT_PRECISION to an integer from 1 through 17 to choose the significant-digit precision used for floating-point interpreter output.

Output

The CLI writes colored source, diagnostics, intermediate code, and interpreter output when attached to an interactive terminal. Redirected output remains plain text. Scanner diagnostics show a caret under the source character that caused the error, followed by a human-readable error message.

Architecture

SourceReader -> PascalScanner -> PascalParserTopDown -> Intermediate Code -> BackendProcessor
                   |                    |                     |
                   +-> Token messages   +-> Diagnostics         +-> Interpreter or code generator

SourceReader, Parser, and BackendProcessor publish Messaging.Message instances to listeners. The CLI listeners format these events without coupling the front end to console output.

Development notes

• Pascal keywords are matched case-insensitively.
• The scanner represents Pascal REAL literals as .NET double values.
• The included Pascal samples are smoke-test inputs, not a full Pascal conformance suite.
• compile currently reports instruction-generation metadata but does not emit executable instructions.