Jp proc (#196)

* Start on procedures

* Add jp-proc tests

CHANGELOG.md

@@ -4,6 +4,12 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 The structure and content of this file follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [1.26.0] - 2024-12-31
+### Added
+- Support for non-selector scripts added to the jp package. See the
+  `jp.CompileScript` variable along with the `Proc` fragment type and
+  `Procedure` interface.
+
 ## [1.25.1] - 2024-12-26
 ### Fixed
 - Fixed precision loss with some fraction parsing.

jp/get.go

@@ -836,6 +836,28 @@ func (x Expr) Get(data any) (results []any) {
 					stack = stack[:before]
 				}
 			}
+		case *Proc:
+			got := tf.Procedure.Get(prev)
+			if int(fi) == len(x)-1 { // last one
+				results = append(results, got...)
+			} else {
+				for i := len(got) - 1; 0 <= i; i-- {
+					v = got[i]
+					switch v.(type) {
+					case nil, bool, string, float64, float32, gen.Bool, gen.Float, gen.String,
+						int, uint, int8, int16, int32, int64, uint8, uint16, uint32, uint64, gen.Int:
+					case map[string]any, []any, gen.Object, gen.Array, Keyed, Indexed:
+						stack = append(stack, v)
+					default:
+						if rt := reflect.TypeOf(v); rt != nil {
+							switch rt.Kind() {
+							case reflect.Ptr, reflect.Slice, reflect.Struct, reflect.Array, reflect.Map:
+								stack = append(stack, v)
+							}
+						}
+					}
+				}
+			}
 		}
 		if int(fi) < len(x)-1 {
 			if _, ok := stack[len(stack)-1].(fragIndex); !ok {
@@ -1626,6 +1648,28 @@ func (x Expr) FirstFound(data any) (any, bool) {
 					return result, true
 				}
 			}
+		case *Proc:
+			if int(fi) == len(x)-1 { // last one
+				return tf.Procedure.First(prev), true
+			} else {
+				got := tf.Procedure.Get(prev)
+				for i := len(got) - 1; 0 <= i; i-- {
+					v = got[i]
+					switch v.(type) {
+					case nil, bool, string, float64, float32, gen.Bool, gen.Float, gen.String,
+						int, uint, int8, int16, int32, int64, uint8, uint16, uint32, uint64, gen.Int:
+					case map[string]any, []any, gen.Object, gen.Array, Keyed, Indexed:
+						stack = append(stack, v)
+					default:
+						if rt := reflect.TypeOf(v); rt != nil {
+							switch rt.Kind() {
+							case reflect.Ptr, reflect.Slice, reflect.Struct, reflect.Array, reflect.Map:
+								stack = append(stack, v)
+							}
+						}
+					}
+				}
+			}
 		}
 		if int(fi) < len(x)-1 {
 			if _, ok := stack[len(stack)-1].(fragIndex); !ok {

jp/parse.go

@@ -213,7 +213,7 @@ func (p *parser) afterBracket() Frag {
 	case '?':
 		return p.readFilter()
 	case '(':
-		p.raise("scripts not implemented yet")
+		return p.readProc()
 	case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
 		var i int
 		i, b = p.readInt(b)
@@ -561,6 +561,19 @@ func (p *parser) readFilter() *Filter {
 	return eq.Filter()
 }
 
+func (p *parser) readProc() *Proc {
+	end := bytes.Index(p.buf, []byte{')', ']'})
+	if end < 0 {
+		p.raise("not terminated")
+	}
+	end++
+	code := p.buf[p.pos-1 : end]
+	p.pos = end + 1
+
+	return MustNewProc(code)
+
+}
+
 // Reads an equation by reading the left value first and then seeing if there
 // is an operation after that. If so it reads the next equation and decides
 // based on precedent which is contained in the other.

jp/parse_test.go

@@ -17,6 +17,7 @@ type xdata struct {
 }
 
 func TestParse(t *testing.T) {
+	jp.CompileScript = nil
 	for i, d := range []xdata{
 		{src: "@", expect: "@"},
 		{src: "$", expect: "$"},
@@ -87,7 +88,8 @@ func TestParse(t *testing.T) {
 		{src: "[]", err: "parse error at 2 in []"},
 		{src: "[**", err: "not terminated at 4 in [**"},
 		{src: "['x'z]", err: "invalid bracket fragment at 6 in ['x'z]"},
-		{src: "[(x)]", err: "scripts not implemented yet at 3 in [(x)]"},
+		{src: "[(x)]", err: "jp.CompileScript has not been set"},
+		{src: "[(x)", err: "not terminated at 3 in [(x)"},
 		{src: "[-x]", err: "expected a number at 4 in [-x]"},
 		{src: "[0x]", err: "invalid bracket fragment at 4 in [0x]"},
 		{src: "[x]", err: "parse error at 2 in [x]"},

jp/proc.go

@@ -0,0 +1,88 @@
+// Copyright (c) 2024, Peter Ohler, All rights reserved.
+
+package jp
+
+import (
+	"fmt"
+)
+
+// CompileScript if non-nil should return object that implments the Procedure
+// interface. This function is called when a script notation bracketed by [(
+// and )] is encountered. Note the string code argument will included the open
+// and close parenthesis but not the square brackets.
+var CompileScript func(code []byte) Procedure
+
+// Proc is a script used as a procedure which is a script not limited to being
+// a selector. While both Locate() and Walk() are supported the results may
+// not be as expected since the procedure can modify the original
+// data. Remove() is not supported with this fragment type.
+type Proc struct {
+	Procedure Procedure
+	Script    []byte
+}
+
+// MustNewProc creates a new Proc and panics on error.
+func MustNewProc(code []byte) (p *Proc) {
+	if CompileScript == nil {
+		panic(fmt.Errorf("jp.CompileScript has not been set"))
+	}
+	return &Proc{
+		Procedure: CompileScript(code),
+		Script:    code,
+	}
+}
+
+// String representation of the proc.
+func (p *Proc) String() string {
+	return string(p.Append([]byte{}, true, false))
+}
+
+// Append a fragment string representation of the fragment to the buffer
+// then returning the expanded buffer.
+func (p *Proc) Append(buf []byte, _, _ bool) []byte {
+	buf = append(buf, "["...)
+	buf = append(buf, p.Script...)
+
+	return append(buf, ']')
+}
+
+func (p *Proc) locate(pp Expr, data any, rest Expr, max int) (locs []Expr) {
+	got := p.Procedure.Get(data)
+	if len(rest) == 0 { // last one
+		for i := range got {
+			locs = locateAppendFrag(locs, pp, Nth(i))
+			if 0 < max && max <= len(locs) {
+				break
+			}
+		}
+	} else {
+		cp := append(pp, nil) // place holder
+		for i, v := range got {
+			cp[len(pp)] = Nth(i)
+			locs = locateContinueFrag(locs, cp, v, rest, max)
+			if 0 < max && max <= len(locs) {
+				break
+			}
+		}
+	}
+	return
+}
+
+// Walk each element returned from the procedure call. Note that this may or
+// may not correspond to the original data as the procedure can modify not only
+// the elements in the original data but also the contents of each.
+func (p *Proc) Walk(rest, path Expr, nodes []any, cb func(path Expr, nodes []any)) {
+	path = append(path, nil)
+	data := nodes[len(nodes)-1]
+	nodes = append(nodes, nil)
+
+	for i, v := range p.Procedure.Get(data) {
+		path[len(path)-1] = Nth(i)
+		nodes[len(nodes)-1] = v
+		if 0 < len(rest) {
+			rest[0].Walk(rest[1:], path, nodes, cb)
+		} else {
+			cb(path, nodes)
+		}
+	}
+}

jp/proc_test.go

@@ -0,0 +1,161 @@
+// Copyright (c) 2024, Peter Ohler, All rights reserved.
+
+package jp_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/ohler55/ojg/jp"
+	"github.com/ohler55/ojg/pretty"
+	"github.com/ohler55/ojg/tt"
+)
+
+type mathProc struct {
+	op    rune
+	left  int
+	right int
+}
+
+func (mp *mathProc) Get(data any) []any {
+	return []any{mp.First(data)}
+}
+
+func (mp *mathProc) First(data any) any {
+	a, ok := data.([]any)
+	if ok {
+		var (
+			left  int
+			right int
+		)
+		if mp.left < len(a) {
+			left, _ = a[mp.left].(int)
+		}
+		if mp.right < len(a) {
+			right, _ = a[mp.right].(int)
+		}
+		switch mp.op {
+		case '+':
+			return left + right
+		case '-':
+			return left - right
+		}
+		return 0
+	}
+	return nil
+}
+
+func compileMathProc(code []byte) jp.Procedure {
+	var mp mathProc
+	_, _ = fmt.Sscanf(string(code), "(%c %d %d)", &mp.op, &mp.left, &mp.right)
+
+	return &mp
+}
+
+type mapProc struct{}
+
+func (mp mapProc) Get(data any) (result []any) {
+	a, _ := data.([]any)
+	for i, v := range a {
+		result = append(result, map[string]any{"i": i, "v": v})
+	}
+	return
+}
+
+func (mp mapProc) First(data any) any {
+	if a, _ := data.([]any); 0 < len(a) {
+		return map[string]any{"i": 0, "v": a[0]}
+	}
+	return nil
+}
+
+func compileMapProc(code []byte) jp.Procedure {
+	return mapProc{}
+}
+
+type mapIntProc struct{}
+
+func (mip mapIntProc) Get(data any) (result []any) {
+	a, _ := data.([]int)
+	for i, v := range a {
+		result = append(result, map[string]int{"i": i, "v": v})
+	}
+	return
+}
+
+func (mip mapIntProc) First(data any) any {
+	if a, _ := data.([]int); 0 < len(a) {
+		return map[string]int{"i": 0, "v": a[0]}
+	}
+	return nil
+}
+
+func compileMapIntProc(code []byte) jp.Procedure {
+	return mapIntProc{}
+}
+
+func TestProcLast(t *testing.T) {
+	jp.CompileScript = compileMathProc
+
+	p := jp.MustNewProc([]byte("(+ 0 1)"))
+	tt.Equal(t, "[(+ 0 1)]", p.String())
+
+	x := jp.MustParseString("[(+ 0 1)]")
+	tt.Equal(t, "[(+ 0 1)]", x.String())
+
+	data := []any{2, 3, 4}
+	result := x.First(data)
+	tt.Equal(t, 5, result)
+
+	got := x.Get(data)
+	tt.Equal(t, []any{5}, got)
+
+	locs := x.Locate(data, 1)
+	tt.Equal(t, "[[0]]", pretty.SEN(locs))
+
+	var buf []byte
+	x.Walk(data, func(path jp.Expr, nodes []any) {
+		buf = fmt.Appendf(buf, "%s : %v\n", path, nodes)
+	})
+	tt.Equal(t, "[0] : [[2 3 4] 5]\n", string(buf))
+}
+
+func TestProcNotLast(t *testing.T) {
+	jp.CompileScript = compileMapProc
+
+	x := jp.MustParseString("[(quux)].v")
+	tt.Equal(t, "[(quux)].v", x.String())
+
+	data := []any{2, 3, 4}
+	result := x.First(data)
+	tt.Equal(t, 2, result)
+
+	got := x.Get(data)
+	tt.Equal(t, []any{2, 3, 4}, got)
+
+	locs := x.Locate(data, 2)
+	tt.Equal(t, "[[0 v] [1 v]]", pretty.SEN(locs))
+
+	var buf []byte
+	x.Walk(data, func(path jp.Expr, nodes []any) {
+		buf = fmt.Appendf(buf, "%s : %v\n", path, nodes)
+	})
+	tt.Equal(t, `[0].v : [[2 3 4] map[i:0 v:2] 2]
+[1].v : [[2 3 4] map[i:1 v:3] 3]
+[2].v : [[2 3 4] map[i:2 v:4] 4]
+`, string(buf))
+}
+
+func TestProcNotLastReflect(t *testing.T) {
+	jp.CompileScript = compileMapIntProc
+
+	x := jp.MustParseString("[(quux)].v")
+	tt.Equal(t, "[(quux)].v", x.String())
+
+	data := []int{2, 3, 4}
+	result := x.First(data)
+	tt.Equal(t, 2, result)
+
+	got := x.Get(data)
+	tt.Equal(t, []any{2, 3, 4}, got)
+}

jp/procedure.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2025, Peter Ohler, All rights reserved.
+
+package jp
+
+// Procedure defines the interface for functions for script fragments between
+// [( and )] delimiters.
+type Procedure interface {
+	// Get should return a list of matching in the data element.
+	Get(data any) []any
+
+	// First should return a single matching in the data element or nil if
+	// there are no matches.
+	First(data any) any
+}