The DSL

The DSL is the user-facing layer of nkdsl. It is designed to keep operator construction declarative and readable.

The core pieces are:

• nkdsl.SymbolicDiscreteJaxOperator or the alias nkdsl.DOperator

• selectors such as nkdsl.site(), nkdsl.emitted(), and nkdsl.symbol() (including default/doc/dtype declarations)

• predicates built with nkdsl.ir.PredicateExpr

• update programs built with nkdsl.Update and helper functions such as nkdsl.shift() or nkdsl.write()

• emissions that attach a rewrite rule and matrix element to each active visit

• compiler-integrated linting that reports actionable diagnostics at compile time

For custom fluent extensions, see Extending the DSL.

Linting

The DSL includes a compiler-integrated linting pass that runs during .compile(). It checks unresolved symbols, index-safety issues, and sampled connectivity validity (support, constraints, and local basis values).

Start with Linting for the overall workflow and policy options. Use Lint Messages for the full diagnostic message catalog with examples and resolutions.

• The Symbolic Operator
  • Important builder rules
  • Term metadata
  • Hermiticity and dtype
• Selectors and expressions
  • Selectors
  • Useful selector properties
  • Symbol declarations
  • Amplitude expressions
  • ExpressionContext
• Emissions and matrix elements
  • Multi-emission semantics
  • Conditional emission chains
  • Connected-state dedup semantics
  • Source and emitted state access
  • Complex matrix elements and dtype promotion
  • Extending emission clauses
• Linting
  • Lint Messages
  • Why linting exists
  • When linting runs
  • Configuration
  • Reading lint output
  • Severity semantics
  • Lint message catalog
  • Recommended workflow
  • Important notes
• Currently Supported
  • NetKet integration
  • Supported Hilbert spaces
  • Current DSL dictionary
  • Useful current limits to remember
• Iterators
  • globally()
  • for_each_site(label)
  • for_each_pair(label_a, label_b)
  • for_each_distinct_pair(label_a, label_b)
  • Static K-body iterators
• Conditions
  • where(predicate)
  • Comparison predicates
  • Logical composition
• Updates
  • identity()
  • shift(site_ref, delta)
  • hop(src, dst, amount=1)
  • shift_mod(site_ref, delta)
  • write(site_ref, value)
  • swap(...) and permute(...)
  • affine(...) and scatter(...)