handle multiple source files

Author: kuba--

README.md

@@ -1,5 +1,5 @@
- <img src="logo.png" name="logo" width="200" /> 
- 
+ <img src="logo.png" name="logo" width="200" />
+
 
 
 # uast2pl
@@ -10,10 +10,10 @@ It takes *UAST* node as an input and tries to produce equivalent prolog program.
 ### Tools
 - `./cmd/uast2pl -f fib.py -o fib.py.pl`.
 Transforms source code into _uast_ (thanks to babelfish) and next transforms _uast_ into a prolog representation.
-```bash
+```
 Usage of ./uast2pl:
-  -f string
-    	input file to parse
+  -f value
+    	list of input source files
   -o string
     	output file (by default stdio)
   -s string
@@ -22,14 +22,14 @@ Usage of ./uast2pl:
 
 - `./cmd/qpl -f fib.py.pl -q "identifier([_, Name, [_, Start, _], _])."`.
 Embedded [_wam_](https://en.wikipedia.org/wiki/Warren_Abstract_Machine) lets query prolog DB.
-```bash
+```
 Usage of ./qpl:
   -f value
     	list of input prolog files
-  -o string
-    	output file (by default stdio)
   -q string
     	prolog query
+  -o string
+    	output file (by default stdio)
 ```
 
 ### Example (extract identifiers)

cmd/uast2pl/main.go

@@ -5,26 +5,39 @@ import (
 	"flag"
 	"io"
 	"os"
+	"strings"
 
 	bblfsh "github.com/bblfsh/go-client/v4"
+
 	"github.com/mloncode/uast2pl"
 )
 
+type stringList []string
+
+func (l *stringList) String() string {
+	return strings.Join(*l, ",")
+}
+
+func (l *stringList) Set(value string) error {
+	*l = append(*l, value)
+	return nil
+}
+
 var (
-	input  string
+	files  stringList
 	host   string
 	output string
 )
 
 func init() {
-	flag.StringVar(&input, "f", "", "input file to parse")
+	flag.Var(&files, "f", "list of input source files")
 	flag.StringVar(&host, "s", "localhost:9432", "address:port of babelfish server")
 	flag.StringVar(&output, "o", "", "output file (by default stdio)")
 }
 
 func main() {
 	flag.Parse()
-	if input == "" {
+	if len(files) == 0 {
 		flag.Usage()
 		os.Exit(1)
 	}
@@ -35,11 +48,15 @@ func main() {
 	}
 	defer client.Close()
 
+	nodes := make([]bblfsh.Node, len(files))
 	req := client.NewParseRequest()
-	req = req.ReadFile(input)
-	n, _, err := req.UAST()
-	if err != nil {
-		panic(err)
+	for i, f := range files {
+		req = req.ReadFile(f)
+		n, _, err := req.UAST()
+		if err != nil {
+			panic(err)
+		}
+		nodes[i] = n
 	}
 
 	var w io.Writer = os.Stdout
@@ -52,7 +69,7 @@ func main() {
 		}
 	}
 
-	if err = uast2pl.WriteNode(w, n); err != nil {
+	if err = uast2pl.WriteNode(w, nodes...); err != nil {
 		panic(err)
 	}
 }

import.pl

@@ -1,4 +1,4 @@
-% join is a private predicate - the same predicate as stdlib's append/3 or merge/3 (from list module).
+% join_ is a private predicate - the same predicate as stdlib's append/3 or merge/3 (from list module).
 join_([], List, List).
 join_([Head | Tail], List, [Head | NewList]) :- !, join_(Tail, List, NewList).
 

list.pl

@@ -1,6 +1,8 @@
-merge([], L, L).
-merge([H | T], L, [H | LL]) :- !, merge(T, L, LL).
+% merge is the same predicate as stdlib's append/3
+merge([], List, List).
+merge([Head | Tail], List, [Head | NewList]) :- !, merge(Tail, List, NewList).
 
+% flatten is true if FlatList is a non-nested version of NestedList.
+flatten([Head | Tail], FlatList) :- !, flatten(Head, HeadFlatList), flatten(Tail, TailFlatList), merge(HeadFlatList, TailFlatList, FlatList).
+flatten(Elem, [Elem]) :- !.
 flatten([], []) :- !.
-flatten([H | T], L) :- !, flatten(H, HL), flatten(T, TL), merge(HL, TL, L).
-flatten(L, [L]) :- !.

uast2pl.go

@@ -11,15 +11,20 @@ import (
 	"github.com/bblfsh/sdk/v3/uast/role"
 )
 
-// WriteNode writes bblfsh Node as prolog terms and predicates.
-func WriteNode(w io.Writer, n nodes.Node) error {
+// WriteNode writes bblfsh node(s) as prolog terms and predicates.
+func WriteNode(w io.Writer, n ...nodes.Node) (err error) {
 	pl := &uast2pl{
 		w:            w,
 		valuesMap:    make(map[string]int),
 		startEndsMap: make(map[uast.Position]int),
 		rolesMap:     make(map[role.Role]int),
 	}
-	_, err := pl.writeNode(n)
+
+	for _, ni := range n {
+		if _, err = pl.writeNode(ni); err != nil {
+			return err
+		}
+	}
 
 	err = pl.writeDeclaration(err, "value", "Val", pl.values)
 	err = pl.writeDeclaration(err, "array", "[Arguments]", pl.arrays)
@@ -118,6 +123,7 @@ func (pl *uast2pl) writeValue(val nodes.Value) (string, error) {
 	quote := ""
 	if val.Kind() == nodes.KindString {
 		quote = "'"
+		v = strings.TrimSpace(v)
 	}
 
 	i = len(pl.values)