mlr altkv

go/src/miller/cli/mlrcli_mappers.go

@@ -11,6 +11,7 @@ import (
 
 // ----------------------------------------------------------------
 var MAPPER_LOOKUP_TABLE = []mapping.MapperSetup{
+	mappers.AltkvSetup,
 	mappers.BootstrapSetup,
 	mappers.CatSetup,
 	mappers.CheckSetup,

go/src/miller/mappers/altkv.go

@@ -0,0 +1,121 @@
+package mappers
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strconv"
+
+	"miller/clitypes"
+	"miller/mapping"
+	"miller/types"
+)
+
+// ----------------------------------------------------------------
+var AltkvSetup = mapping.MapperSetup{
+	Verb:         "altkv",
+	ParseCLIFunc: mapperAltkvParseCLI,
+	IgnoresInput: false,
+}
+
+func mapperAltkvParseCLI(
+	pargi *int,
+	argc int,
+	args []string,
+	errorHandling flag.ErrorHandling, // ContinueOnError or ExitOnError
+	_ *clitypes.TReaderOptions,
+	__ *clitypes.TWriterOptions,
+) mapping.IRecordMapper {
+
+	// Get the verb name from the current spot in the mlr command line
+	argi := *pargi
+	verb := args[argi]
+	argi++
+
+	// Parse local flags
+	flagSet := flag.NewFlagSet(verb, errorHandling)
+
+	flagSet.Usage = func() {
+		ostream := os.Stderr
+		if errorHandling == flag.ContinueOnError { // help intentionally requested
+			ostream = os.Stdout
+		}
+		mapperAltkvUsage(ostream, args[0], verb, flagSet)
+	}
+	flagSet.Parse(args[argi:])
+	if errorHandling == flag.ContinueOnError { // help intentionally requested
+		return nil
+	}
+
+	// Find out how many flags were consumed by this verb and advance for the
+	// next verb
+	argi = len(args) - len(flagSet.Args())
+
+	mapper, _ := NewMapperAltkv()
+
+	*pargi = argi
+	return mapper
+}
+
+func mapperAltkvUsage(
+	o *os.File,
+	argv0 string,
+	verb string,
+	flagSet *flag.FlagSet,
+) {
+	fmt.Fprintf(o, "Usage: %s %s {no options}\n", argv0, verb)
+	fmt.Fprintf(o, "Given fields with values of the form a,b,c,d,e,f emits a=b,c=d,e=f pairs.\n")
+
+	flagSet.VisitAll(func(f *flag.Flag) {
+		fmt.Fprintf(o, " -%v (default %v) %v\n", f.Name, f.Value, f.Usage) // f.Name, f.Value
+	})
+}
+
+// ----------------------------------------------------------------
+type MapperAltkv struct {
+}
+
+func NewMapperAltkv() (*MapperAltkv, error) {
+	this := &MapperAltkv{}
+	return this, nil
+}
+
+// ----------------------------------------------------------------
+func (this *MapperAltkv) Map(
+	inrecAndContext *types.RecordAndContext,
+	outputChannel chan<- *types.RecordAndContext,
+) {
+	inrec := inrecAndContext.Record
+	if inrec != nil { // not end of record stream
+		newrec := types.NewMlrmapAsRecord()
+		outputFieldNumber := 1
+
+		fmt.Printf("\n");
+		for pe := inrec.Head; pe != nil; /* increment in loop body */ {
+			if pe.Next != nil { // Not at end of record with odd-numbered field count
+				key := pe.Value.String()
+				value := pe.Next.Value
+				// Transferring ownership from old record to new record; no copy needed
+				newrec.PutReference(&key, value)
+			} else { // At end of record with odd-numbered field count
+				key := strconv.Itoa(outputFieldNumber)
+				value := pe.Value
+				// Transferring ownership from old record to new record; no copy needed
+				newrec.PutReference(&key, value)
+			}
+			outputFieldNumber++
+
+			pe = pe.Next
+			if pe == nil {
+				break
+			}
+			pe = pe.Next
+		}
+		fmt.Printf("\n");
+
+		outputChannel <- types.NewRecordAndContext(newrec, &inrecAndContext.Context)
+
+	} else { // end of record stream
+		outputChannel <- inrecAndContext
+	}
+}

go/todo.txt

@@ -3,6 +3,11 @@ TOP OF LIST:
 
 * UDFs
 * local vars w/ typing
+* Check for "Options:" in all mappers
+
+* default ifs/ofs to space not comma for nidx. & what else did i miss?
+
+* sliding-window averages (C + Go)
 
 * some more verbs
   o altkv decimate having-fields remove-empty-columns reorder

go/u/try-help.out

@@ -1,3 +1,7 @@
+================================================================
+Usage: ./mlr altkv {no options}
+Given fields with values of the form a,b,c,d,e,f emits a=b,c=d,e=f pairs.
+
 ================================================================
 Usage: ./mlr bootstrap [options]
 Emits an n-sample, with replacement, of the input records.

go/u/try-verbs

@@ -75,3 +75,6 @@ run_mlr --opprint --from u/s.dkvp grep -i -v PAN
 
 run_mlr --from u/s.dkvp skip-trivial-records
 run_mlr --from u/skip-trivial-records.dkvp skip-trivial-records
+
+echo 'a,b,c,d,e,f'   | run_mlr --inidx --ifs comma altkv
+echo 'a,b,c,d,e,f,g' | run_mlr --inidx --ifs comma altkv

go/u/try-verbs.out

@@ -523,3 +523,15 @@ a=eks,b=wye,i=4,x=0.38139939387114097,y=0.13418874328430463
 mlr --from u/skip-trivial-records.dkvp skip-trivial-records
 a=1,b=2
 c=4,d=
+
+----------------------------------------------------------------
+mlr --inidx --ifs comma altkv
+
+
+a=b,c=d,e=f
+
+----------------------------------------------------------------
+mlr --inidx --ifs comma altkv
+
+
+a=b,c=d,e=f,4=g

go/verbs-to-do

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+diff <(mlr -L) <(../c/mlr -L) | grep '>' | nf | cat -n