Add command line options for glj -e --version --help -h (#88)

* Support 'glj -e ...' commands

* Add *glojure-version* dynamic variable

* Support 'glj --version'

* Support --help and -h CLI options

* Fix 'make test', add 'make build', 'make clean'

The CLI tests require 'bin/<os-arch>/glc' binary to be built in order to
run 'glj ...' commands and test the output.

Author: ingydotnet

Makefile

@@ -6,6 +6,28 @@ STDLIB := $(STDLIB_ORIGINALS:scripts/rewrite-core/originals/%=%)
 STDLIB_ORIGINALS := $(addprefix scripts/rewrite-core/originals/,$(STDLIB))
 STDLIB_TARGETS := $(addprefix pkg/stdlib/glojure/,$(STDLIB:.clj=.glj))
 
+OS-TYPE := $(shell bash -c 'echo $$OSTYPE')
+OS-NAME := \
+  $(if $(findstring darwin,$(OS-TYPE))\
+	,macos,$(if $(findstring linux,$(OS-TYPE)),linux,))
+ARCH-TYPE := $(shell bash -c 'echo $$MACHTYPE')
+ARCH-NAME := \
+  $(if $(or $(findstring arm64,$(ARCH-TYPE)),\
+	          $(findstring aarch64,$(ARCH-TYPE)))\
+	,arm64,$(if $(findstring x86_64,$(ARCH-TYPE)),int64,))
+
+ifdef OS-NAME
+ifdef ARCH-NAME
+OS-ARCH := $(OS-NAME)-$(ARCH-NAME)
+OA-linux-arm64 := linux_arm64
+OA-linux-int64 := linux_amd64
+OA-macos-arm64 := darwin_arm64
+OA-macos-int64 := darwin_amd64
+OA := $(OA-$(OS-ARCH))
+GLJ := bin/$(OA)/glj
+endif
+endif
+
 TEST_FILES := $(shell find ./test -name '*.glj' | sort)
 TEST_TARGETS := $(addsuffix .test,$(TEST_FILES))
 
@@ -31,6 +53,13 @@ gocmd:
 generate:
 	@go generate ./...
 
+.PHONY: build
+build: $(GLJ)
+
+.PHONY: clean
+clean:
+	$(RM) -r bin/
+
 pkg/gen/gljimports/gljimports_%.go: ./scripts/gen-gljimports.sh ./cmd/gen-import-interop/main.go ./internal/genpkg/genpkg.go \
 					$(wildcard ./pkg/lang/*.go) $(wildcard ./pkg/runtime/*.go)
 	@echo "Generating $@"
@@ -56,7 +85,7 @@ vet:
 	@go vet ./...
 
 .PHONY: $(TEST_TARGETS)
-$(TEST_TARGETS): gocmd
+$(TEST_TARGETS): gocmd $(GLJ)
 	@$(GO_CMD) run ./cmd/glj/main.go $(basename $@)
 
 .PHONY: test

README.md

@@ -2,7 +2,8 @@
 
 ![example workflow](https://github.com/glojurelang/glojure/actions/workflows/ci.yml/badge.svg)
 
-[Try it in your browser!](https://glojurelang.github.io/glojure/) (fair warning: startup on the web is slow)
+[Try it in your browser!](https://glojurelang.github.io/glojure/)
+(fair warning: startup on the web is slow)
 
 <img alt="Gopher image" src="./doc/logo.png" width="512" />
 
@@ -51,14 +52,28 @@ user=>
 
 ## Usage
 
-Glojure can be used in two ways: as a standalone command-line tool (`glj`) or embedded within Go applications.
+Glojure can be used in two ways: as a standalone command-line tool (`glj`) or
+embedded within Go applications.
 
 ### Using the `glj` Command
 
 The `glj` command provides a traditional Clojure development experience:
 
+**Show the help:**
+```
+$ glj --help   # or glj -h
+```
+
+**Show the version:**
+```
+$ glj --version
+glojure v0.3.0
+```
+
 **Start a REPL (interactive session):**
 ```
+user=> *glojure-version*
+{:major 0, :minor 3, :incremental 0, :qualifier nil}
 $ glj
 user=> (+ 1 2 3)
 6
@@ -67,6 +82,18 @@ Hello from Glojure!
 nil
 ```
 
+**Evaluate expressions:**
+```
+$ glj -e '(println "Hello, World!")'
+Hello, World!
+$ glj -e '(apply + (range 3 10))'
+42
+$ glj -e '
+(defn factorial [n] (if (<= n 1) 1 (* n (factorial (dec n)))))
+(factorial 5)'
+120
+```
+
 **Run a Clojure script:**
 ```clojure
 ;; hello.glj
@@ -100,7 +127,8 @@ Server starting on :8080...
 
 ### Embedding Glojure in Go Applications
 
-You can also embed Glojure as a scripting language within your Go applications. This is useful when you want to:
+You can also embed Glojure as a scripting language within your Go applications.
+This is useful when you want to:
 - Add scriptable configuration to your Go application
 - Allow users to extend your application with Clojure plugins
 - Mix Go's performance with Clojure's expressiveness
@@ -185,6 +213,7 @@ runtime.ReadEval(`
 - Writing standalone Clojure programs
 - Interactive development with the REPL
 - Running Clojure scripts
+- Evaluating expressions directly from the command line
 - Learning Clojure with Go interop
 
 **Embed Glojure for:**

pkg/gljmain/gljmain.go

@@ -2,8 +2,10 @@ package gljmain
 
 import (
 	"bufio"
+	"fmt"
 	"log"
 	"os"
+	"strings"
 
 	// bootstrap the runtime
 	_ "github.com/glojurelang/glojure/pkg/glj"
@@ -14,20 +16,82 @@ import (
 	"github.com/glojurelang/glojure/pkg/runtime"
 )
 
+func printHelp() {
+	fmt.Printf(`Glojure v%s
+
+Usage: glj [options] [file]
+
+Options:
+  -e <expr>        Evaluate expression from command line
+  -h, --help       Show this help message
+  --version        Show version information
+
+Examples:
+  glj                   # Start REPL
+  glj -e "(+ 1 2)"      # Evaluate expression
+  glj script.glj        # Run script file
+  glj --version         # Show version
+  glj --help            # Show this help
+
+For more information, visit: https://github.com/glojurelang/glojure
+`, runtime.VERSION)
+}
+
 func Main(args []string) {
 	runtime.AddLoadPath(os.DirFS("."))
 
 	if len(args) == 0 {
 		repl.Start()
+	} else if args[0] == "--version" {
+		fmt.Printf("glojure v%s\n", runtime.VERSION)
+		return
+	} else if args[0] == "--help" || args[0] == "-h" {
+		printHelp()
+		return
+	} else if args[0] == "-e" {
+		// Evaluate expression from command line
+		if len(args) < 2 {
+			log.Fatal("glj: -e requires an expression")
+		}
+		expr := args[1]
+		env := lang.GlobalEnv
+
+		// Set command line args (everything after -e and the expression)
+		core := lang.FindNamespace(lang.NewSymbol("glojure.core"))
+		core.FindInternedVar(lang.NewSymbol("*command-line-args*")).BindRoot(lang.Seq(args[2:]))
+
+		rdr := reader.New(strings.NewReader(expr), reader.WithGetCurrentNS(func() *lang.Namespace {
+			return env.CurrentNamespace()
+		}))
+		var lastResult interface{}
+		for {
+			val, err := rdr.ReadOne()
+			if err == reader.ErrEOF {
+				break
+			}
+			if err != nil {
+				log.Fatal(err)
+			}
+			result, err := env.Eval(val)
+			if err != nil {
+				log.Fatal(err)
+			}
+			lastResult = result
+		}
+		// Print only the final result unless it's nil
+		if !lang.IsNil(lastResult) {
+			fmt.Println(lang.PrintString(lastResult))
+		}
 	} else {
-		file, err := os.Open(os.Args[1])
+		// Execute file
+		file, err := os.Open(args[0])
 		if err != nil {
 			log.Fatal(err)
 		}
 		env := lang.GlobalEnv
 
 		core := lang.FindNamespace(lang.NewSymbol("glojure.core"))
-		core.FindInternedVar(lang.NewSymbol("*command-line-args*")).BindRoot(lang.Seq(os.Args[2:]))
+		core.FindInternedVar(lang.NewSymbol("*command-line-args*")).BindRoot(lang.Seq(args[1:]))
 
 		rdr := reader.New(bufio.NewReader(file), reader.WithGetCurrentNS(func() *lang.Namespace {
 			return env.CurrentNamespace()

pkg/runtime/envinit.go

@@ -5,13 +5,48 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 	"strings"
 
 	"github.com/glojurelang/glojure/pkg/lang"
 	"github.com/glojurelang/glojure/pkg/reader"
 	"github.com/glojurelang/glojure/pkg/stdlib"
 )
 
+// The current version of Glojure
+const VERSION = "0.3.0"
+
+// ParseVersion parses the VERSION string and returns a map with major, minor,
+// incremental, and qualifier
+func ParseVersion(version string) lang.IPersistentMap {
+	parts := strings.Split(version, ".")
+
+	major, _ := strconv.Atoi(parts[0])
+	minor, _ := strconv.Atoi(parts[1])
+
+	incremental := 0
+	qualifier := interface{}(nil)
+
+	if len(parts) > 2 {
+		// Check if the third part contains a qualifier (e.g., "0-alpha")
+		incrementalPart := parts[2]
+		if strings.Contains(incrementalPart, "-") {
+			qualifierParts := strings.SplitN(incrementalPart, "-", 2)
+			incremental, _ = strconv.Atoi(qualifierParts[0])
+			qualifier = qualifierParts[1]
+		} else {
+			incremental, _ = strconv.Atoi(incrementalPart)
+		}
+	}
+
+	return lang.NewMap(
+		lang.NewKeyword("major"), major,
+		lang.NewKeyword("minor"), minor,
+		lang.NewKeyword("incremental"), incremental,
+		lang.NewKeyword("qualifier"), qualifier,
+	)
+}
+
 type Program struct {
 	nodes []interface{}
 }
@@ -113,6 +148,13 @@ func NewEnvironment(opts ...EvalOption) lang.Environment {
 		evalFile("glojure/core.glj")
 	}
 
+	// Set the glojure version
+	core := lang.FindNamespace(lang.NewSymbol("glojure.core"))
+	versionVar := core.FindInternedVar(lang.NewSymbol("*glojure-version*"))
+	if versionVar != nil {
+		versionVar.BindRoot(ParseVersion(VERSION))
+	}
+
 	return env
 }
 

pkg/runtime/environment.go

@@ -63,6 +63,7 @@ func newEnvironment(ctx context.Context, stdout, stderr io.Writer) *environment
 		"print-meta",
 		"print-dup",
 		"read-eval",
+		"glojure-version",
 	} {
 		coreNS.InternWithValue(lang.NewSymbol("*"+dyn+"*"), nil, true).SetDynamic()
 	}

test/glojure/test_glojure/cli.glj

@@ -0,0 +1,77 @@
+(ns glojure.test-glojure.cli
+  (:use glojure.test)
+  (:require [glojure.string :as str]))
+
+(defmacro #^{:private true} test-that
+  "Provides a useful way for specifying the purpose of tests. If the first-level
+  forms are lists that make a call to a glojure.test function, it supplies the
+  purpose as the msg argument to those functions. Otherwise, the purpose just
+  acts like a comment and the forms are run unchanged."
+  [purpose & test-forms]
+  (let [tests (map
+               #(if (= (:ns (meta (resolve (first %))))
+                       (the-ns 'glojure.test))
+                  (concat % (list purpose))
+                  %)
+               test-forms)]
+    `(do ~@tests)))
+
+(defn run-cli-cmd [& args]
+  (let [bytes-to-string (fn [bytes]
+                          (if (nil? bytes)
+                            ""
+                            (apply str (map char (seq bytes)))))
+        cmd (apply os$exec.Command args)
+        [output err] (.CombinedOutput cmd)]
+    [(bytes-to-string output) (bytes-to-string err)]))
+
+(def glj
+  (let [[out err] (run-cli-cmd "find" "bin" "-name" "glj" "-executable")]
+    (if (and (seq out) (empty? err))
+      (first (str/split-lines out))
+      (throw (Exception. (str "Failed to find glj bin: " err))))))
+
+(deftest e-flag-test
+  (test-that
+   "glj -e flag works correctly"
+   (let [[out err] (run-cli-cmd glj "-e" "(* 6 7)")]
+     (is (= out "42\n") "Command should output 42")
+     (is (empty? err) "Command should not return an error"))))
+
+(deftest version-flag-test
+  (test-that
+   "glj --version flag works correctly"
+   (let [[out err] (run-cli-cmd glj "--version")]
+     (is (re-matches #"glojure v\d+\.\d+\.\d+\n" out)
+         "Command should output version")
+     (is (empty? err) "Command should not return an error"))))
+
+(deftest glojure-version-test
+  (test-that
+   "*glojure-version* should be set correctly"
+   (let [[out err] (run-cli-cmd glj "-e" "*glojure-version*")]
+     (is (= out "{:major 0, :minor 3, :incremental 0, :qualifier nil}\n")
+         "Version should match expected format")
+     (is (empty? err) "Command should not return an error"))))
+
+(deftest help-flag-test
+  (test-that
+   "glj --help flag works correctly"
+   (let [[out err] (run-cli-cmd glj "--help")]
+     (is (re-matches
+          #"(?s).*Glojure v0\.3\.0.*Usage: glj.*Options:.*-e.*-h.*--help.*--version.*Examples:.*"
+          out)
+         "Command should output help information")
+     (is (empty? err) "Command should not return an error"))))
+
+(deftest short-help-flag-test
+  (test-that
+   "glj -h flag works correctly"
+   (let [[out err] (run-cli-cmd glj "-h")]
+     (is (re-matches
+          #"(?s).*Glojure v0\.3\.0.*Usage: glj.*Options:.*-e.*-h.*--help.*--version.*Examples:.*"
+          out)
+         "Command should output help information")
+     (is (empty? err) "Command should not return an error"))))
+
+(run-tests)