In the PAST

• After producing a parse tree, transform it to an abstract syntax tree
• Pugs Intermediate Language (PIL) as a starting point
• PIL basic node types (still changing)

PVal      A literal value
PVar      A variable
PNoop     No-op
PAssign   Assignment operation
PBind     Binding operation
PApp      All other operations, function calls, or method calls
PSub      A subroutine declaration
PCode     A code block
PExp      An expression
PStmt     A statement
PStmts    A sequence of statements
PNil      A list-terminator for PStmts lists (Lisp-style)
PLit      An intermediate node for literal values
PRawName  An intermediate node for variable names
PThunk    Node for lazy or deferred evaluation
PPad      Create a new lexical pad
PPos      Current parse location in the source code (for
          issuing useful debugging messages)