From 8bb321f8b032dfaeffbe3d1b8dfeb215c12d3642 Mon Sep 17 00:00:00 2001
From: "Juan J. Martinez" <jjm@usebox.net>
Date: Mon, 18 Jul 2022 07:45:58 +0100
Subject: First public release

---
 cmd/micro/micro.go | 202 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 202 insertions(+)
 create mode 100644 cmd/micro/micro.go

(limited to 'cmd/micro')

diff --git a/cmd/micro/micro.go b/cmd/micro/micro.go
new file mode 100644
index 0000000..3e5c9e6
--- /dev/null
+++ b/cmd/micro/micro.go
@@ -0,0 +1,202 @@
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"path"
+	"strings"
+	"time"
+
+	"usebox.net/lang/interpreter"
+	"usebox.net/lang/parser"
+	"usebox.net/lang/tokenizer"
+)
+
+const name = "micro"
+
+var Version = "<unset>"
+
+func perror(err error) {
+	fmt.Fprintln(os.Stderr, err)
+
+	first := err
+	for {
+		perr := err
+		err = errors.Unwrap(err)
+		if err == nil {
+			if perr.Error() != first.Error() {
+				fmt.Fprintf(os.Stderr, "%s\n", perr)
+			}
+			break
+		}
+	}
+}
+
+func fatal(errno int, err error) {
+	perror(err)
+	os.Exit(errno)
+}
+
+func fatals(typ string, errno int, err error) {
+	fmt.Fprintf(os.Stderr, "%s: %s\n", name, typ)
+	fatal(errno, err)
+}
+
+func repl() {
+	scanner := bufio.NewScanner(os.Stdin)
+	p := parser.NewParser(interpreter.BuiltInTypes())
+	i := interpreter.NewInterpreter()
+
+	fmt.Printf("Welcome to %s %s\nType in expressions for evaluation, or :q to exit.\n\n", strings.Title(name), Version)
+
+	repl := 0
+	for {
+		fmt.Printf("%s> ", name)
+		var line string
+		multiline := false
+		for {
+			if multiline {
+				fmt.Print("  | ")
+				line += " "
+			}
+			if !scanner.Scan() {
+				fmt.Println()
+				return
+			}
+			r := scanner.Text()
+			if r == ":q" {
+				return
+			}
+			line += r
+
+			if !multiline {
+				if r == "" {
+					continue
+				}
+				if r[len(r)-1] != ';' {
+					multiline = true
+					continue
+				}
+				break
+			}
+			if r == "" {
+				break
+			}
+		}
+
+		in := strings.NewReader(line)
+		repl++
+		t := tokenizer.NewTokenizer(fmt.Sprintf("in%d", repl), in)
+		ts, err := t.Scan()
+		if err != nil {
+			perror(err)
+			continue
+		}
+
+		tree, err := p.Parse(ts)
+		if err != nil {
+			perror(err)
+			continue
+		}
+
+		for _, expr := range tree {
+			v, err := i.Interp(expr)
+			if err != nil {
+				perror(err)
+				break
+			}
+			if v != nil {
+				fmt.Println(v)
+			}
+		}
+	}
+}
+
+func usage() {
+	me := path.Base(os.Args[0])
+	fmt.Fprintf(os.Stderr,
+		"Usage: %s [options] ... [file]\nOptions:\n", me)
+	flag.PrintDefaults()
+	fmt.Fprintln(os.Stderr)
+}
+
+func main() {
+	fVersion := flag.Bool("V", false, "display version and exit")
+	fParse := flag.Bool("parse", false, "parse reporting any errors and exit")
+	fDebugTokens := flag.Bool("tokens", false, "dump to stderr tokens and exit")
+	fDebugAst := flag.Bool("ast", false, "dump to stderr AST and exit")
+	fTime := flag.Bool("time", false, "measure execution time")
+	flag.Usage = usage
+	flag.Parse()
+
+	if *fVersion {
+		fmt.Printf("%s %s\n", name, Version)
+		os.Exit(0)
+	}
+
+	var input *os.File
+	var filename = flag.Arg(0)
+
+	if filename == "" {
+		repl()
+		os.Exit(0)
+	} else {
+		var err error
+		input, err = os.Open(filename)
+		if err != nil {
+			fatals("error opening input file", 1, err)
+		}
+	}
+	t := tokenizer.NewTokenizer(filename, input)
+	ts, err := t.Scan()
+	if err != nil {
+		fatals("parsing error", 10, err)
+	}
+
+	if *fDebugTokens {
+		out, err := json.MarshalIndent(ts, "", "  ")
+		if err != nil {
+			fatals("encoding error", 11, err)
+		}
+		fmt.Fprintf(os.Stderr, "%s\n", string(out))
+		os.Exit(0)
+	}
+
+	p := parser.NewParser(interpreter.BuiltInTypes())
+	tree, err := p.Parse(ts)
+	if *fParse {
+		if err != nil {
+			perror(err)
+			os.Exit(1)
+		}
+		os.Exit(0)
+	}
+	if err != nil {
+		fatal(20, err)
+	}
+
+	if *fDebugAst {
+		out, err := json.MarshalIndent(tree, "", "  ")
+		if err != nil {
+			fatals("encoding error", 21, err)
+		}
+		fmt.Fprintf(os.Stderr, "%s\n", string(out))
+		os.Exit(0)
+	}
+
+	start := time.Now()
+	i := interpreter.NewInterpreter()
+	for _, expr := range tree {
+		if _, err := i.Interp(expr); err != nil {
+			fatal(31, err)
+		}
+	}
+
+	if *fTime {
+		fmt.Fprintf(os.Stderr, "elapsed: %f\n", time.Since(start).Seconds())
+	}
+}
-- 
cgit v1.2.3