PL/1 Parser (Front End)

The PL/1 parser (front end) enables the construction of PL/1 custom compilers, analysis tools, or source transformation tools. It is a member of SD's family of language front ends, based on first-class infrastructure (DMS) for implementing such custom tools. The PL/1 front end includes:

  • Lexical analysis including EBCDIC, ASCII and ISO 8859-1
    • Conversion of literal values (numbers, escaped strings) into native values to enable easy computation over literal values
    • String literals represented internally in Unicode to support 16-bit characters
  • Explicit grammar directly implements defacto and real standards and extensions
    • Full PL/1 level G parser
    • Stratus PL/1 dialect
    • SabreTalk PL/1 variant dialect
    • Easy extension for other dialects
  • Automatic construction of complete abstract syntax tree
    • Capture of comments and formats (shape) of literal values
    • Capture of ambiguous parses during parsing
    • Ability to parse large systems of files into same workspace, enabling interprocedural and cross-file analysis/transformation
    • Ability to parse different languages into same workspace, enabling cross-language analysis/transformation
  • Facilities to process syntax trees
    • Complete procedural API to visit/query/update/construct/print syntax trees
    • Source regeneration by prettyprinting and/or fidelity printing of syntax trees with comments and lexical formats
    • Automatically generated source-to-source transformation system
    • Ability to define custom attribute-grammar-based analyzers
  • Name and Type resolution
    • Type representation system for all PL/1 types defined
    • All identifiers resolved to their defined type and stored in symbol tables
    • Automatic deletion of erroneous alternatives of ambiguous parses
    • Ability to query expression trees for derived type
    • Ability to condition transforms on identifier type or expression type
    • Abilility to visit/query/update symbol tables
  • Available as source code to enable complete customization

Many of these facilities come as a consistent consequence of the front end being built on top of DMS.

Here are some sample tools (many offered by SD as products) built using the PL/1 front end:

SD also offers:

Your organization may use DMS with the PL/1 front end to implement and deploy your own custom tools. The sample tools can be obtained in source form as part of the PL/1 front end for customization. Semantic Designs is also willing to build custom tools under contract.

For more information:    Follow us at Twitter: @SemanticDesigns

C Parser
Front End