flowclass/aggregates.go

package flowclass

import (
	"bytes"
	"fmt"

	"idio.link/go/parser"
)

type fcVector[A parser.ASTNode, _ any] struct {
	dim      int
	newToken func() A
}

func (t fcVector[_, _]) Shift(sm *parser.SM, e rune) error {
	length := len(sm.Top().Nodes)
	if length == 0 {
		return sm.Push(t.newToken()).Shift(sm, e)
	}
	switch e {
	case ' ', ')':
	case ',':
		if length == t.dim {
			return fmt.Errorf("vector: too many components")
		}
		sm.Push(t.newToken())
	default:
		return parser.NewUnrecognized("vector", e)
	}
	return nil
}

func (t fcVector[_, B]) Coalesce(nodes []*parser.CSTNode) any {
	col := make([]B, 0, 8)
	for _, e := range nodes {
		col = append(col, e.Coalesce().(B))
	}
	return col
}

func (t fcVector[_, _]) Value() *bytes.Buffer {
	return nil
}

type fcSet[A parser.ASTNode, _ fmt.Stringer] struct {
	newToken func() A
}

func (t fcSet[_, _]) Shift(sm *parser.SM, e rune) error {
	switch {
	case e == ' ':
	case e == ',':
	case e == '}':
	case isAlpha(e) || isDigit(e):
		return sm.Push(t.newToken()).Shift(sm, e)
	default:
		if len(sm.Top().Nodes) == 0 {
			return fmt.Errorf("set: cannot be the empty set")
		}
		return parser.NewUnrecognized("set", e)
	}
	return nil
}

func (t fcSet[_, B]) Coalesce(nodes []*parser.CSTNode) any {
	col := make(map[string]B)
	for _, e := range nodes {
		tmp := e.Coalesce().(B)
		col[tmp.String()] = tmp
	}
	return col
}

func (t fcSet[_, _]) Value() *bytes.Buffer {
	return nil
}