Add support for prelude

[inkytonik]

We can now separately process a prelude Cooma definition and read its information in to the execution of a different Cooma program (or REPL). This mechanism constitutes a simple form of separate compilation.

It all works via the new -P option which processes a prelude and generates:

• A static file that contains names and types of prelude-defined entities. In the case of prelude types it also contains their definition.

• A dynamic file that contains IR for the prelude.

The new -p option specifies the prelude to use in a run. The corresponding static and dynamic files will be loaded into the compiler and runtime before analysing and executing the user's code. The static file provides an initial environment for semantic analysis. The IR code in the dynamic file is executed to produce an initial environment for execution. Thus, all of the entities defined in the prelude are available automatically in user code.

The default prelude is prelude/prelude.cooma. After any changes, we need to reprocess it with -P to get the default static and dynamic files.

The new -Q option can be used to run without using a prelude.

Details of main changes:

• Config

  • add prelude-related options (-p, -P and -Q)

• Main

  • add invocation of prelude driver if -P specified

• cooma.syntax

  • Cooma: remove constructs that are defined in prelude (Boolean-related things, Ints, Strings, Vectors, equal)
  • Cooma: remove syntactic capability types in favour of identifiers from prelude (e.g., Reader)
  • IR: add syntax definition to get parser for prelude processing and replace old hand-written pretty-printer
  • IR: alter syntax to make it easier to parse, e.g., more keywords
  • IR: prefix keywords with % so they can't clash with identifiers
  • IR: prefix generated identifiers with $ so they can't clash with user names
  • IR: encode continuation syntax properly rather than just using identifiers (new Cont syntax category)
  • prelude: add syntax of static and dynamic prelude files
  • fix some small pretty-printing bugs

• SemanticAnalysis

  • some reorganisation to tidy-up checking code
  • remove hard-coded typing of constructs that are now in the prelude
  • add support for pre-defined entities. These come from the compilation of the prelude and are loaded from the static file.

• Compiler

  • add positions parameter to main compilation methods for use in setting positions of target constructs; this replaces the use of source parameters in backend IR creation API
  • put most of compiler in CompilerCore class to make it easy to access the positions from anywhere
  • remove hard-coded types and compilation of values that now come from prelude

• Server

  • hover support for primitive types and operations plus pre-defined entities from prelude

• SymbolTable

  • add entity kinds for pre-defined functions and let-defined values
  • fix bug in isPrimitiveTypeName where bitwise or was used instead of logical or
  • remove hard-coded types for things now defined in prelude (e.g., readerT)
  • add support for building initial environment from prelude static file

• Util

  • add $ prefix to fresh variable names to distinguish from user identifiers

• Primitives

  • replace object-oriented style with functional one since the abstract syntax of primitives is now generated from grammar
  • make Primitives into a trait so it can be mixed-in with backends instead of requiring backend parameters

• Interpreter

  • some rearrangement to make parameter orders more logical and consistent (e.g., ClsC, ConsCE etc)
  • remove source node propagation since it's handled in compiler now
  • add support for reading dynamic prelude file to initialise runtime environment
  • remove linking in runtime value pretty-printing

• Backend

  • remove source parameters from Term and ValueR constructor methods
  • rename FieldValue to FldV to better match other types and operations
  • use FldV in variant values (varV) as in record values (recV)
  • remove primitive methods (now in syntax)
  • unitR is now uniR to better match other constructs
  • add showTerm for backend-specific way to print Term
  • add stdout writer for use by primitives
  • maintain string values in escaped form to correct output issues

• ReferenceBackend

  • conform to new smaller Backend API
  • remove classes for IR definition, since they are generated from syntax spec now
  • remove hand-coded IR pretty-printer since we use a generated one now

• CoomaLanguage

  • add support for reading dynamic prelude

• other Truffle-side changes

  • add Rats!-defined parser that builds Truffle CoomaTerm nodes
  • adapt to adjusted Term syntax and simplified Backend API
  • use new syntax-defined Primitive constructs
  • remove some unneeded code for processing halt continuations
  • remove an unused connection to the pretty-printer from the Java side

• tests

  • adjust IR and IRAST test output for new IR syntax
  • standardise on default lowercase starting letter for test titles
  • semantic tests:
  • adapt primitive tests for new functional-style
  • add some missing vector tests
  • execution tests:
  • add a test of environment capture
  • add a test of unit equality
  • adjust types for new prelude processing
  • adapt primitive tests for new functional-style
  • allow for "no type" in REPL tests, since we have some programs that don't type at the moment
  • add tests of Vector primitives
  • add more tests of user-defined type aliases
  • add prelude tests
  • add some missing vector tests

• README

  • fix paths to test files