From 0524d105904be5dc48c4bfdeda4eddaa9c7b5dff Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Tue, 26 Jul 2016 14:20:11 -0400
Subject: [PATCH] parse | pipe lines.

---
 command.cpp         | 11 +++++++++--
 command.h           |  6 ++----
 phase2-parser.lemon |  7 ++++---
 phase2.rl           | 21 +++++++++++++++++++++
 4 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/command.cpp b/command.cpp
index a500eb5..95db807 100644
--- a/command.cpp
+++ b/command.cpp
@@ -372,7 +372,7 @@ int break_command::execute(Environment &env, const fdmask &fds, bool throwup) {
 
 	env.echo("%s", s.c_str());
 	if (!env.loop()) {
-		fputs("MPW Shell - Break must be within for or loop.\n", stderr);
+		fputs("### MPW Shell - Break must be within for or loop.\n", stderr);
 		return env.status(-3, throwup);
 	}
 
@@ -394,7 +394,7 @@ int continue_command::execute(Environment &env, const fdmask &fds, bool throwup)
 
 	env.echo("%s", s.c_str());
 	if (!env.loop()) {
-		fputs("MPW Shell - Continue must be within for or loop.\n", stderr);
+		fputs("### MPW Shell - Continue must be within for or loop.\n", stderr);
 		return env.status(-3, throwup);
 	}
 
@@ -433,6 +433,13 @@ int and_command::execute(Environment &e, const fdmask &fds, bool throwup) {
 }
 
 
+int pipe_command::execute(Environment &e, const fdmask &fds, bool throwup) {
+	// not yet supported!
+	fputs( "### MPW Shell - Pipes are not yet supported.\n", stderr);
+	return e.status(1, throwup);
+}
+
+
 int vector_command::execute(Environment &e, const fdmask &fds, bool throwup) {
 
 	int rv = 0;
diff --git a/command.h b/command.h
index f554574..68b07b2 100644
--- a/command.h
+++ b/command.h
@@ -114,15 +114,13 @@ struct and_command : public binary_command {
 };
 
 
-#if 0
 struct pipe_command : public binary_command {
-	and_command(command_ptr &&a, command_ptr &&b) :
+	pipe_command(command_ptr &&a, command_ptr &&b) :
 		binary_command(PIPE, std::move(a), std::move(b)) 
 	{}
 
-	virtual int execute(Environment &e) final override;
+	virtual int execute(Environment &e, const fdmask &fds, bool throwup) final override;
 };
-#endif
 
 
 struct vector_command : public command {
diff --git a/phase2-parser.lemon b/phase2-parser.lemon
index 2f00c1b..5ecc2d6 100644
--- a/phase2-parser.lemon
+++ b/phase2-parser.lemon
@@ -29,6 +29,9 @@ bool phase2_parser::continuation() const {
 		if (e.major == PIPE_PIPE) return true;
 		if (e.major == LOOP) return true;
 		if (e.major == FOR) return true;
+		if (e.major == PIPE) return true;
+		if (e.major == PIPE_PIPE) return true;
+		if (e.major == AMP_AMP) return true;
 	}
 	return false;
 }
@@ -92,11 +95,9 @@ command(RV) ::= command(L) AMP_AMP opt_nl command(R). {
 	RV = std::make_unique<and_command>(std::move(L), std::move(R));
 }
 
-/*
-command(RV) ::= command PIPE opt_nl command. {
+command(RV) ::= command(L) PIPE opt_nl command(R). {
 	RV = std::make_unique<pipe_command>(std::move(L), std::move(R));
 }
-*/
 
 command(RV) ::= term(T). { RV = std::move(T); }
 
diff --git a/phase2.rl b/phase2.rl
index 779cc83..b5ab4ca 100644
--- a/phase2.rl
+++ b/phase2.rl
@@ -42,6 +42,25 @@
 		}
 	}
 
+	action parse_pipe_any {
+		if (!special()) {
+			scratch.pop_back();
+			flush();
+			parse(PIPE, "|");
+		}
+		fhold;
+		fgoto main;
+	}
+
+	action parse_pipe_eof {
+
+		if (!special()) {
+			scratch.pop_back();
+			flush();
+			parse(PIPE, "|");
+		}
+	}
+
 	action parse_lparen {
 		if (scratch.empty()) {
 			parse(LPAREN, "(");
@@ -88,6 +107,8 @@
 		| ';' $parse_semi
 		| '(' $parse_lparen
 		| ')' $parse_rparen
+		| '|' <eof(parse_pipe_eof)
+		| '|' [^|] $parse_pipe_any
 		| '|' '|' $parse_pipe_pipe
 		| '&' '&' $parse_amp_amp
 		| escape_seq