From: Luca Bruno <lucabru@src.gnome.org>
Date: Fri, 30 Dec 2011 08:26:26 +0000 (+0100)
Subject: parser: Allow to parse expressions/statements from string
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e7cbff0fd7ebc8912382cde727208b417106fbb1;p=thirdparty%2Fvala.git

parser: Allow to parse expressions/statements from string
---

diff --git a/vala/valaparser.vala b/vala/valaparser.vala
index 10c42d6d6..ee1907d36 100644
--- a/vala/valaparser.vala
+++ b/vala/valaparser.vala
@@ -29,6 +29,8 @@ public class Vala.Parser : CodeVisitor {
 	Scanner scanner;
 
 	CodeContext context;
+	bool compiler_code = false;
+	SourceReference? from_string_reference = null;
 
 	// token buffer
 	TokenInfo[] tokens;
@@ -145,17 +147,28 @@ public class Vala.Parser : CodeVisitor {
 	}
 
 	SourceReference get_src (SourceLocation begin) {
-		int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE;
+		if (from_string_reference != null) {
+			return from_string_reference;
+		}
 
+		int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE;
 		return new SourceReference (scanner.source_file, begin, tokens[last_index].end);
 	}
 
 	SourceReference get_current_src () {
+		if (from_string_reference != null) {
+			return from_string_reference;
+		}
+
 		var token = tokens[index];
 		return new SourceReference (scanner.source_file, token.begin, token.end);
 	}
 
 	SourceReference get_last_src () {
+		if (from_string_reference != null) {
+			return from_string_reference;
+		}
+
 		int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE;
 		var token = tokens[last_index];
 		return new SourceReference (scanner.source_file, token.begin, token.end);
@@ -263,6 +276,11 @@ public class Vala.Parser : CodeVisitor {
 			}
 			break;
 		default:
+			if (compiler_code && current () == TokenType.DOT) {
+				next();
+				next();
+				return;
+			}
 			throw new ParseError.SYNTAX ("expected identifier");
 		}
 	}
@@ -322,6 +340,54 @@ public class Vala.Parser : CodeVisitor {
 		}
 	}
 
+	public Expression? parse_expression_string (string str, SourceReference source_reference) {
+		Expression? result = null;
+
+		compiler_code = true;
+		context = source_reference.file.context;
+		from_string_reference = source_reference;
+
+		scanner = new Scanner.from_string (str, source_reference.file);
+		index = -1;
+		size = 0;
+
+		next ();
+
+		try {
+			result = parse_expression ();
+		} catch (Error e) {
+			Report.error (source_reference, "internal error: %s".printf (e.message));
+		}
+
+		scanner = null;
+		from_string_reference = null;
+		compiler_code = false;
+
+		return result;
+	}
+
+	public void parse_statements_string (string str, Block block, SourceReference source_reference) {
+		compiler_code = true;
+		context = source_reference.file.context;
+		from_string_reference = source_reference;
+
+		scanner = new Scanner.from_string (str, source_reference.file);
+		index = -1;
+		size = 0;
+
+		next ();
+
+		try {
+			parse_statements (block);
+		} catch (Error e) {
+			Report.error (source_reference, "internal error: %s".printf (e.message));
+		}
+
+		scanner = null;
+		from_string_reference = null;
+		compiler_code = false;
+	}
+
 	public void parse_file (SourceFile source_file) {
 		var has_global_context = (context != null);
 		if (!has_global_context) {
@@ -361,6 +427,9 @@ public class Vala.Parser : CodeVisitor {
 	}
 
 	void skip_symbol_name () throws ParseError {
+		if (compiler_code && accept (TokenType.DOT)) {
+			// temporary variable
+		}
 		do {
 			skip_identifier ();
 		} while (accept (TokenType.DOT) || accept (TokenType.DOUBLE_COLON));
@@ -682,7 +751,14 @@ public class Vala.Parser : CodeVisitor {
 
 	Expression parse_simple_name () throws ParseError {
 		var begin = get_location ();
-		string id = parse_identifier ();
+		string id;
+		if (compiler_code && accept (TokenType.DOT)) {
+			// temporary variable
+			next ();
+			id = "."+get_last_string ();
+		} else {
+			id = parse_identifier ();
+		}
 		bool qualified = false;
 		if (id == "global" && accept (TokenType.DOUBLE_COLON)) {
 			id = parse_identifier ();
@@ -1590,6 +1666,10 @@ public class Vala.Parser : CodeVisitor {
 					break;
 				default:
 					bool is_expr = is_expression ();
+					if (!is_expr && compiler_code && current () == TokenType.DOT) {
+						// compiler variable assignment
+						is_expr = true;
+					}
 					if (is_expr) {
 						stmt = parse_expression_statement ();
 					} else {
diff --git a/vala/valascanner.vala b/vala/valascanner.vala
index 718b65471..6a5a38624 100644
--- a/vala/valascanner.vala
+++ b/vala/valascanner.vala
@@ -28,6 +28,7 @@ using GLib;
  */
 public class Vala.Scanner {
 	public SourceFile source_file { get; private set; }
+	string buffer;
 
 	TokenType previous;
 	char* current;
@@ -69,6 +70,19 @@ public class Vala.Scanner {
 		column = 1;
 	}
 
+	public Scanner.from_string (string str, SourceFile source_file) {
+		this.source_file = source_file;
+		buffer = str; // keep alive
+
+		char* begin = str;
+		end = begin + str.length;
+
+		current = begin;
+
+		line = 1;
+		column = 1;
+	}
+
 	public void seek (SourceLocation location) {
 		current = location.pos;
 		line = location.line;