prodigy.pgcl.ppy_printer

Pretty printer for .ppy

Prints a pGCL AST in the .ppy syntax, with the canonical spelling and, or and not. Parsing the output with prodigy.pgcl.ppy_parser.parse_ppy() gives back an equal AST; the converter from .pgcl is built on this.

Comments are not part of the AST and are lost.

>>> from prodigy.pgcl.parser import parse_pgcl
>>> print(program_to_ppy(parse_pgcl("nat x; rparam p; {x := x + 1} [p] {x := 0}; ?Pr[x = 1]")), end="")
x: nat;
param p: real;
{
    x = x + 1;
} [p] {
    x = 0;
}
query Pr[x == 1];

exception PpyPrintError

Bases: ValueError

The AST cannot be written in .ppy (e.g. a name that is a keyword there).

expr_to_ppy(expr)

Print an expression in the .ppy syntax.

>>> from prodigy.pgcl.parser import parse_expectation
>>> expr_to_ppy(parse_expectation("not (x = 1) & y^2 < -x + 1"))
'not x == 1 and y ** 2 < -(x + 1)'

Parameters:

expr (VarExpr | BoolLitExpr | NatLitExpr | RealLitExpr | UnopExpr | BinopExpr | CategoricalExpr | SubstExpr | TickExpr | FunctionCallExpr | InferExpr | SampleExpr)

Return type:

str

instr_to_ppy(instr)

Print an instruction (or query) in the .ppy syntax.

Parameters:

instr (SkipInstr | AbortInstr | WhileInstr | IfInstr | AsgnInstr | ChoiceInstr | LoopInstr | TickInstr | ObserveInstr | QueryInstr | LocalDeclInstr | ProbabilityQueryInstr | ExpectationInstr | PlotInstr | PrintInstr | OptimizationQuery)

Return type:

str

decl_to_ppy(decl)

Print a declaration in the .ppy syntax.

Parameters:

decl (VarDecl | ConstDecl | ParameterDecl | FunctionDecl)

Return type:

str

program_to_ppy(program)

Print a program in the .ppy syntax, declarations first.

Parameters:

program (Program)

Return type:

str