From e1d2c83ff6d6b5b9b7ad50bd56f08129cbbf5c2c Mon Sep 17 00:00:00 2001
From: Henrixounez <30901439+Henrixounez@users.noreply.github.com>
Date: Sun, 18 Aug 2019 21:50:38 +0200
Subject: [PATCH] repl: functions and conditional blocks support

---
 compiler/main.v                             |  63 ---------
 compiler/repl.v                             | 148 ++++++++++++++++++++
 compiler/tests/repl/conditional_blocks.repl |  18 +++
 compiler/tests/repl/function.repl           |  11 ++
 compiler/tests/repl/repl_test.v             |   2 +-
 5 files changed, 178 insertions(+), 64 deletions(-)
 create mode 100644 compiler/repl.v
 create mode 100644 compiler/tests/repl/conditional_blocks.repl
 create mode 100644 compiler/tests/repl/function.repl

diff --git a/compiler/main.v b/compiler/main.v
index c2cb7026ae..03ae2b27d5 100644
--- a/compiler/main.v
+++ b/compiler/main.v
@@ -1323,69 +1323,6 @@ fn new_v(args[]string) *V {
 	}
 }
 
-fn run_repl() []string {
-	println('V $Version')
-	println('Use Ctrl-C or `exit` to exit')
-	file := '.vrepl.v'
-	temp_file := '.vrepl_temp.v'
-	defer {
-		os.rm(file)
-		os.rm(temp_file)
-		os.rm(file.left(file.len - 2))
-		os.rm(temp_file.left(temp_file.len - 2))
-	}
-	mut lines := []string
-	vexe := os.args[0]
-	for {
-		print('>>> ')
-		mut line := os.get_raw_line()
-		if line.trim_space() == '' && line.ends_with('\n') {
-			continue
-		}
-		line = line.trim_space()
-		if line.len == -1 || line == '' || line == 'exit' {
-			break
-		}
-		if line == '\n' {
-			continue
-		}
-		// Save the source only if the user is printing something,
-		// but don't add this print call to the `lines` array,
-		// so that it doesn't get called during the next print.
-		if line.starts_with('print') {
-			source_code := lines.join('\n') + '\n' + line
-			os.write_file(file, source_code)
-			s := os.exec('$vexe run $file -repl') or {
-				panic(err)
-			}
-			vals := s.output.split('\n')
-			for i:=0; i < vals.len; i++ {
-				println(vals[i])
-			}
-		}
-		else {
-			mut temp_line := line
-			mut temp_flag := false
-			if !(line.contains(' ') || line.contains(':') || line.contains('=') || line.contains(',') ){
-				temp_line = 'println($line)'
-				temp_flag = true
-			}
-			temp_source_code := lines.join('\n') + '\n' + temp_line
-			os.write_file(temp_file, temp_source_code)
-			s := os.exec('$vexe run $temp_file -repl') or {
-				panic(err)
-			}
-			if !s.exit_code {
-				lines << line
-			}
-			vals := s.output.split('\n')
-			for i:=0; i<vals.len; i++ {
-				println(vals[i])
-			}
-		}
-	}
-	return lines
-}
 
 const (
 	HelpText = '
diff --git a/compiler/repl.v b/compiler/repl.v
new file mode 100644
index 0000000000..4c3fa1b961
--- /dev/null
+++ b/compiler/repl.v
@@ -0,0 +1,148 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module main
+
+import os
+
+struct Repl {
+mut:
+	indent         int
+	in_func        bool
+	lines          []string
+	temp_lines     []string
+	functions_name []string
+	functions      []string
+}
+
+fn (r mut Repl) checks(line string) bool {
+	mut in_string := false
+	was_indent := r.indent > 0
+
+	for i := 0; i < line.len; i++ {
+		if line[i] == `\'` && line[i - 1] != `\\` {
+			in_string = !in_string
+		}
+		if line[i] == `{` && !in_string {
+			r.indent++
+		}
+		if line[i] == `}` && !in_string {
+			r.indent--
+			if r.indent == 0 {
+				r.in_func = false
+			}
+		}
+		if i + 2 < line.len && r.indent == 0 && line[i + 1] == `f` && line[i + 2] == `n` {
+			r.in_func = true
+		}
+	}
+	return r.in_func || (was_indent && r.indent <= 0) || r.indent > 0
+}
+
+fn (r mut Repl) function_call(line string) bool {
+	for function in r.functions_name {
+		if line.starts_with(function) {
+			return true
+		}
+	}
+	return false
+}
+
+fn run_repl() []string {
+	println('V $Version')
+	println('Use Ctrl-C or `exit` to exit')
+	file := '.vrepl.v'
+	temp_file := '.vrepl_temp.v'
+	defer {
+		os.rm(file)
+		os.rm(temp_file)
+		os.rm(file.left(file.len - 2))
+		os.rm(temp_file.left(temp_file.len - 2))
+	}
+	mut r := Repl{}
+	vexe := os.args[0]
+	for {
+		if r.indent == 0 {
+			print('>>> ')
+		}
+		else {
+			print('... ')
+		}
+		mut line := os.get_raw_line()
+		if line.trim_space() == '' && line.ends_with('\n') {
+			continue
+		}
+		line = line.trim_space()
+		if line.len == -1 || line == '' || line == 'exit' {
+			break
+		}
+		if line == '\n' {
+			continue
+		}
+		if line.starts_with('fn') {
+			r.in_func = true
+			r.functions_name << line.all_after('fn').all_before('(').trim_space()
+		}
+		was_func := r.in_func
+		if r.checks(line) {
+			if r.in_func || was_func {
+				r.functions << line
+			}
+			else {
+				r.temp_lines << line
+			}
+			if r.indent > 0 {
+				continue
+			}
+			line = ''
+		}
+		// Save the source only if the user is printing something,
+		// but don't add this print call to the `lines` array,
+		// so that it doesn't get called during the next print.
+		if line.starts_with('print') {
+			source_code := r.functions.join('\n') + r.lines.join('\n') + '\n' + line
+			os.write_file(file, source_code)
+			s := os.exec('$vexe run $file -repl') or {
+				panic(err)
+			}
+			vals := s.output.split('\n')
+			for i:=0; i < vals.len; i++ {
+				println(vals[i])
+			}
+		}
+		else {
+			mut temp_line := line
+			mut temp_flag := false
+			func_call := r.function_call(line)
+			if !(line.contains(' ') || line.contains(':') || line.contains('=') || line.contains(',') || line == '') && !func_call {
+				temp_line = 'println($line)'
+				temp_flag = true
+			}
+			temp_source_code := r.functions.join('\n') + r.lines.join('\n') + r.temp_lines.join('\n') + '\n' + temp_line
+			os.write_file(temp_file, temp_source_code)
+			s := os.exec('$vexe run $temp_file -repl') or {
+				panic(err)
+			}
+			if !func_call && !s.exit_code {
+				for r.temp_lines.len > 0 {
+					if !r.temp_lines[0].starts_with('print') {
+						r.lines << r.temp_lines[0]
+					}
+					r.temp_lines.delete(0)
+				}
+				r.lines << line
+			}
+			else {
+				for r.temp_lines.len > 0 {
+					r.temp_lines.delete(0)
+				}
+			}
+			vals := s.output.split('\n')
+			for i:=0; i<vals.len; i++ {
+				println(vals[i])
+			}
+		}
+	}
+	return r.lines
+}
\ No newline at end of file
diff --git a/compiler/tests/repl/conditional_blocks.repl b/compiler/tests/repl/conditional_blocks.repl
new file mode 100644
index 0000000000..ca10025c37
--- /dev/null
+++ b/compiler/tests/repl/conditional_blocks.repl
@@ -0,0 +1,18 @@
+if true {
+  println('foo')
+}
+for i := 0; i < 4; i++ {
+  println(i)
+}
+if false {
+  println('foo')
+} else {
+  println('bar')
+}
+===output===
+foo
+0
+1
+2
+3
+bar
diff --git a/compiler/tests/repl/function.repl b/compiler/tests/repl/function.repl
new file mode 100644
index 0000000000..0b20fa1a4e
--- /dev/null
+++ b/compiler/tests/repl/function.repl
@@ -0,0 +1,11 @@
+fn test() {
+  println('foo')
+}
+test()
+fn test2(a int) {
+  println(a)
+}
+test2(42)
+===output===
+foo
+42
diff --git a/compiler/tests/repl/repl_test.v b/compiler/tests/repl/repl_test.v
index 017d1e7560..358b39b6b0 100644
--- a/compiler/tests/repl/repl_test.v
+++ b/compiler/tests/repl/repl_test.v
@@ -14,7 +14,7 @@ fn test_repl() {
       assert false
       break
     }
-    result := r.output.replace('>>> ', '').replace('>>>', '').all_after('Use Ctrl-C or `exit` to exit\n')
+    result := r.output.replace('>>> ', '').replace('>>>', '').replace('... ', '').all_after('Use Ctrl-C or `exit` to exit\n')
     assert result == output
     if result != output {
       println(file)