factor/core/compiler/inference/branches.facts

IN: inference
USING: help kernel kernel-internals ;

HELP: unify-lengths
{ $values { "seq" "a sequence" } { "newseq" "a new sequence" } }
{ $description "Pads sequences in " { $snippet "seq" } " with computed value placeholders to ensure they are all the same length." } ;

HELP: unify-values
{ $values { "seq" "a sequence" } { "value" "an object" } }
{ $description "If all values in the sequence are equal, outputs the value, otherwise outputs a computed value placeholder." } ;

HELP: unbalanced-branches-error
{ $values { "in" "a sequence of integers" } { "out" "a sequence of integers" } }
{ $description "Throws an " { $link unbalanced-branches-error } "." }
{ $error-description "Thrown when inference encounters an " { $link if } ", " { $link dispatch } " or " { $link cond } " where the branches do not all exit with the same stack height." }
{ $notes "Conditionals with variable stack effects are considered to be bad style and should be avoided since they do not compile."
$nl
"If this error comes up when inferring the stack effect of a recursive word, check the word's stack effect declaration; it might be wrong." } ;

HELP: unify-effect
{ $values { "quots" "a sequence of quotations" } { "in" "a sequence of integers" } { "out" "a sequence of stacks" } { "newin" "a sequence of integers" } { "newout" "a sequence of stacks" } }
{ $description "Unifies the stack effects of a number of branches, and outputs new values for " { $link d-in } " and " { $link meta-d } "." } ;