get embedded rules. (6b621d34) · Commits · Kevin Lyda / units

rules/rules.go

+9 −68

Original line number	Diff line number	Diff line
		@@ -2,6 +2,7 @@
		package rules

		import (
		"embed"
		"errors"
		"fmt"

		@@ -13,67 +14,8 @@ type Engine struct {
		p *prolog.Interpreter
		}

		var (
		prologKinds = `
		unit_kind(f, temperature).
		unit_kind(k, temperature).
		unit_kind(c, temperature).
		unit_kind(m2, area).
		unit_kind(cm2, area).
		unit_kind(mm, distance).
		unit_kind(cm, distance).
		unit_kind(m, distance).
		unit_kind(km, distance).
		unit_kind(feet, distance).
		unit_kind(mg, mass).
		unit_kind(g, mass).
		unit_kind(kg, mass).
		unit_kind(lb, mass).
		unit_kind(cup, volume).
		unit_kind(litre, volume).
		unit_kind(butter, density).
		unit_kind(water, density).
		`
		prologConvert = `
		rule(GivenQuant, f, TargetQuant, c) :-
		TargetQuant is (GivenQuant - 32) * 5 / 9.
		rule(GivenQuant, c, TargetQuant, f) :-
		TargetQuant is (GivenQuant / 5 * 9) + 32.
		rule(GivenQuant, c, TargetQuant, k) :-
		TargetQuant is GivenQuant + 273.15.
		rule(GivenQuant, k, TargetQuant, c) :-
		TargetQuant is GivenQuant - 273.15.

		rule(GivenQuant, GivenUnit, TargetQuant, TargetUnit) :-
		rule(GivenQuant, GivenUnit, X, Y),
		rule(X, Y, TargetQuant, TargetUnit).

		ratio(m, km, 0.001).
		ratio(m, cm, 100).
		ratio(m, mm, 1000).
		ratio(feet, m, 0.3048).
		ratio(feet, inches, 12).

		ratio(g, mg, 1000).
		ratio(g, kg, 0.001).

		ratio(X, Y, Ratio) :- ratio(Y, X, Z), Ratio is 1/Z, !.
		ratio(X, Y, Ratio) :-
		ratio(X, Step, R1),
		ratio(Step, Y, R2),
		Step =\= X,
		Step =\= Y,
		Ratio is R1 * R2, !.

		convert(GivenQuant, GivenUnit, TargetQuant, TargetUnit) :-
		unit_kind(GivenUnit, temperature),
		unit_kind(TargetUnit, temperature),
		rule(GivenQuant, GivenUnit, TargetQuant, TargetUnit).
		convert(GivenQuant, GivenUnit, TargetQuant, TargetUnit) :-
		ratio(GivenUnit, TargetUnit, Ratio),
		TargetQuant is GivenQuant * Ratio, !.
		`
		)
		//go:embed source/*
		var src embed.FS

		// New creates a new rules engine.
		func New() (*Engine, error) {
		@@ -81,18 +23,17 @@ func New() (*Engine, error) {
		p: prolog.New(nil, nil),
		}
		// Treat a string argument as an atom.
		if err := ngn.p.Exec(`:- set_prolog_flag(double_quotes, atom).`); err != nil {
		return nil, err
		}
		if err := ngn.p.Exec(`:- set_prolog_flag(debug, on).`); err != nil {
		err := ngn.p.Exec(`:- set_prolog_flag(double_quotes, atom).`)
		if err != nil {
		return nil, err
		}

		if err := ngn.p.Exec(prologKinds); err != nil {
		rules, err := src.ReadFile("source/rules.pdb")
		if err != nil {
		return nil, err
		}

		if err := ngn.p.Exec(prologConvert); err != nil {
		err = ngn.p.Exec(string(rules))
		if err != nil {
		return nil, err
		}