Predicator.Compiler (predicator v3.8.0)

Compiler that converts AST to various representations using visitors.

The compiler orchestrates different visitors to transform Abstract Syntax Trees into executable instructions, string representations, or other formats.

Examples

iex> ast = {:comparison, :gt, {:identifier, "score"}, {:literal, 85}}
iex> Predicator.Compiler.to_instructions(ast)
[["load", "score"], ["lit", 85], ["compare", "GT"]]

# Future visitors will enable:
# iex> Predicator.Compiler.to_string(ast)
# "score > 85"

# iex> Predicator.Compiler.to_dot(ast)
# "digraph {...}"

Summary

Functions

to_instructions(ast, opts \\ [])

Converts an AST to stack machine instructions.

to_instructions_with_positions(ast, opts \\ [])

Converts an AST to stack machine instructions plus a source-position side table.

to_string(ast, opts \\ [])

Converts an AST to a string representation.

Functions

to_instructions(ast, opts \\ [])

@spec to_instructions(
  Predicator.Parser.ast() | Predicator.Parser.bare_ast(),
  keyword()
) :: [[binary() | term()]]

Converts an AST to stack machine instructions.

Uses the InstructionsVisitor to generate a list of instructions that can be executed by the stack-based evaluator.

Parameters

ast - The Abstract Syntax Tree to compile
opts - Optional compiler options

Returns

List of instructions in the format [["operation", ...args]]

Examples

iex> ast = {:literal, 42}
iex> Predicator.Compiler.to_instructions(ast)
[["lit", 42]]

iex> ast = {:comparison, :eq, {:identifier, "name"}, {:literal, "John"}}
iex> Predicator.Compiler.to_instructions(ast)
[["load", "name"], ["lit", "John"], ["compare", "EQ"]]

to_instructions_with_positions(ast, opts \\ [])

@spec to_instructions_with_positions(
  Predicator.Parser.ast() | Predicator.Parser.bare_ast(),
  keyword()
) :: {[[binary() | term()]], Predicator.Types.position_table()}

Converts an AST to stack machine instructions plus a source-position side table.

The instruction list is identical to to_instructions/2's - the side table is a separate Elixir-side value, so the interchange format and any stored compiled artifacts are unaffected (ADR-0001). The table maps each instruction's 0-based index to the {line, column} of the AST node that emitted it; nodes with no position contribute no entry, so a caller-supplied position-free AST yields an empty table.

Examples

iex> ast = {:comparison, :gt, {:identifier, "score", {1, 1}}, {:literal, 85, {1, 9}}, {1, 7}}
iex> Predicator.Compiler.to_instructions_with_positions(ast)
{[["load", "score"], ["lit", 85], ["compare", "GT"]],
 %{0 => {1, 1}, 1 => {1, 9}, 2 => {1, 7}}}

iex> Predicator.Compiler.to_instructions_with_positions({:literal, 42})
{[["lit", 42]], %{}}

to_string(ast, opts \\ [])

@spec to_string(
  Predicator.Parser.ast() | Predicator.Parser.bare_ast(),
  keyword()
) :: binary()

Converts an AST to a string representation.

Uses the StringVisitor to generate a readable string representation of the Abstract Syntax Tree. This is useful for debugging, documentation, and displaying expressions to users.

Parameters

ast - The Abstract Syntax Tree to convert
opts - Optional formatting options:
- :parentheses - :minimal (default) | :explicit | :none
- :spacing - :normal (default) | :compact | :verbose

Returns

String representation of the AST

Examples

iex> ast = {:literal, 42}
iex> Predicator.Compiler.to_string(ast)
"42"

iex> ast = {:comparison, :gt, {:identifier, "score"}, {:literal, 85}}
iex> Predicator.Compiler.to_string(ast)
"score > 85"

iex> ast = {:comparison, :gt, {:identifier, "age"}, {:literal, 21}}
iex> Predicator.Compiler.to_string(ast, parentheses: :explicit)
"(age > 21)"