Value expression architecture is now rewritten, but the functionality of the

old system (for example, the meaning of 'a') has yet to be restored.  In the
new scheme, this will be done by definition a function outside of the value
expression logic, rather than the tight coupling between journal innards and
value expressions that occurred in 2.x.

1 files changed, 445 insertions, 0 deletions

diff --git a/parser.cc b/parser.cc
new file mode 100644
index 00000000..a03ea9df
--- /dev/null
+++ b/parser.cc
@@ -0,0 +1,445 @@
+/*
+ * Copyright (c) 2003-2008, John Wiegley.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of New Artisans LLC nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "parser.h"
+
+namespace ledger {
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_value_term(std::istream& in,
+				   const flags_t tflags) const
+{
+  ptr_op_t node;
+
+  token_t& tok = next_token(in, tflags);
+
+  switch (tok.kind) {
+  case token_t::VALUE:
+    node = new op_t(op_t::VALUE);
+    node->set_value(tok.value);
+    break;
+
+  case token_t::MASK: {
+    // A /mask/ is just a shorthand for calling match().
+    node = new op_t(op_t::O_CALL);
+
+    ptr_op_t ident = new op_t(op_t::IDENT);
+    ident->set_ident("match");
+    node->set_left(ident);
+
+    ptr_op_t args = new op_t(op_t::O_COMMA);
+    node->set_right(args);
+
+    ptr_op_t mask = new op_t(op_t::MASK);
+    mask->set_mask(tok.value.as_string());
+
+    ident = new op_t(op_t::IDENT);
+
+    args->set_left(mask);
+    args->set_right(ident);
+
+    switch (tok.flags()) {
+    case TOKEN_SHORT_ACCOUNT_MASK:
+      ident->set_ident("account_base");
+      break;
+    case TOKEN_CODE_MASK:
+      ident->set_ident("code");
+      break;
+#if 0
+    case TOKEN_COMMODITY_MASK:
+      ident->set_ident("commodity");
+      break;
+#endif
+    case TOKEN_PAYEE_MASK:
+      ident->set_ident("payee");
+      break;
+    case TOKEN_NOTE_MASK:
+      ident->set_ident("note");
+      break;
+    case TOKEN_ACCOUNT_MASK:
+      ident->set_ident("account");
+      break;
+    }
+    break;
+  }
+
+  case token_t::IDENT: {
+#if 0
+#ifdef USE_BOOST_PYTHON
+    if (tok.value->as_string() == "lambda") // special
+      try {
+	char c, buf[4096];
+
+	std::strcpy(buf, "lambda ");
+	READ_INTO(in, &buf[7], 4000, c, true);
+
+	ptr_op_t eval = new op_t(op_t::O_EVAL);
+	ptr_op_t lambda = new op_t(op_t::FUNCTION);
+	lambda->functor = new python_functor_t(python_eval(buf));
+	eval->set_left(lambda);
+	ptr_op_t sym = new op_t(op_t::SYMBOL);
+	sym->name = new string("__ptr");
+	eval->set_right(sym);
+
+	node = eval;
+
+	goto done;
+      }
+      catch(const boost::python::error_already_set&) {
+	throw_(parse_error, "Error parsing lambda expression");
+      }
+#endif /* USE_BOOST_PYTHON */
+#endif
+
+    string ident = tok.value.as_string();
+
+    // An identifier followed by ( represents a function call
+    tok = next_token(in, tflags);
+
+    if (tok.kind == token_t::LPAREN) {
+      node = new op_t(op_t::IDENT);
+      node->set_ident(ident);
+
+      ptr_op_t call_node(new op_t(op_t::O_CALL));
+      call_node->set_left(node);
+      call_node->set_right(parse_value_expr(in, tflags | EXPR_PARSE_PARTIAL));
+
+      tok = next_token(in, tflags);
+      if (tok.kind != token_t::RPAREN)
+	tok.unexpected(0xff, ')');
+
+      node = call_node;
+    } else {
+      if (std::isdigit(ident[0])) {
+	node = new op_t(op_t::INDEX);
+	node->set_index(lexical_cast<unsigned int>(ident.c_str()));
+      } else {
+	node = new op_t(op_t::IDENT);
+	node->set_ident(ident);
+      }
+      push_token(tok);
+    }
+    break;
+  }
+
+  case token_t::LPAREN:
+    node = new op_t(op_t::O_COMMA);
+    node->set_left(parse_value_expr(in, tflags | EXPR_PARSE_PARTIAL));
+    if (! node->left())
+      throw_(parse_error, tok.symbol << " operator not followed by argument");
+
+    tok = next_token(in, tflags);
+    if (tok.kind != token_t::RPAREN)
+      tok.unexpected(0xff, ')');
+    break;
+
+  default:
+    push_token(tok);
+    break;
+  }
+
+#if 0
+#ifdef USE_BOOST_PYTHON
+ done:
+#endif
+#endif
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_unary_expr(std::istream& in,
+				   const flags_t tflags) const
+{
+  ptr_op_t node;
+
+  token_t& tok = next_token(in, tflags);
+
+  switch (tok.kind) {
+  case token_t::EXCLAM: {
+    ptr_op_t term(parse_value_term(in, tflags));
+    if (! term)
+      throw_(parse_error,
+	     tok.symbol << " operator not followed by argument");
+
+    // A very quick optimization
+    if (term->kind == op_t::VALUE) {
+      term->as_value_lval().in_place_negate();
+      node = term;
+    } else {
+      node = new op_t(op_t::O_NOT);
+      node->set_left(term);
+    }
+    break;
+  }
+
+  case token_t::MINUS: {
+    ptr_op_t term(parse_value_term(in, tflags));
+    if (! term)
+      throw_(parse_error,
+	     tok.symbol << " operator not followed by argument");
+
+    // A very quick optimization
+    if (term->kind == op_t::VALUE) {
+      term->as_value_lval().in_place_negate();
+      node = term;
+    } else {
+      node = new op_t(op_t::O_NEG);
+      node->set_left(term);
+    }
+    break;
+  }
+
+  default:
+    push_token(tok);
+    node = parse_value_term(in, tflags);
+    break;
+  }
+
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_mul_expr(std::istream& in,
+				 const flags_t tflags) const
+{
+  ptr_op_t node(parse_unary_expr(in, tflags));
+
+  if (node) {
+    token_t& tok = next_token(in, tflags);
+
+    if (tok.kind == token_t::STAR || tok.kind == token_t::KW_DIV) {
+      ptr_op_t prev(node);
+      node = new op_t(tok.kind == token_t::STAR ?
+		      op_t::O_MUL : op_t::O_DIV);
+      node->set_left(prev);
+      node->set_right(parse_mul_expr(in, tflags));
+      if (! node->right())
+	throw_(parse_error,
+	       tok.symbol << " operator not followed by argument");
+
+      tok = next_token(in, tflags);
+    }
+    push_token(tok);
+  }
+
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_add_expr(std::istream& in,
+				 const flags_t tflags) const
+{
+  ptr_op_t node(parse_mul_expr(in, tflags));
+
+  if (node) {
+    token_t& tok = next_token(in, tflags);
+
+    if (tok.kind == token_t::PLUS ||
+	tok.kind == token_t::MINUS) {
+      ptr_op_t prev(node);
+      node = new op_t(tok.kind == token_t::PLUS ?
+		      op_t::O_ADD : op_t::O_SUB);
+      node->set_left(prev);
+      node->set_right(parse_add_expr(in, tflags));
+      if (! node->right())
+	throw_(parse_error,
+	       tok.symbol << " operator not followed by argument");
+
+      tok = next_token(in, tflags);
+    }
+    push_token(tok);
+  }
+
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_logic_expr(std::istream& in,
+				   const flags_t tflags) const
+{
+  ptr_op_t node(parse_add_expr(in, tflags));
+
+  if (node) {
+    op_t::kind_t kind	= op_t::LAST;
+    flags_t	 _flags = tflags;
+    token_t&	 tok	= next_token(in, tflags);
+
+    switch (tok.kind) {
+    case token_t::EQUAL:
+      if (tflags & EXPR_PARSE_NO_ASSIGN)
+	tok.rewind(in);
+      else
+	kind = op_t::O_EQ;
+      break;
+    case token_t::NEQUAL:
+      kind = op_t::O_NEQ;
+      break;
+    case token_t::LESS:
+      kind = op_t::O_LT;
+      break;
+    case token_t::LESSEQ:
+      kind = op_t::O_LTE;
+      break;
+    case token_t::GREATER:
+      kind = op_t::O_GT;
+      break;
+    case token_t::GREATEREQ:
+      kind = op_t::O_GTE;
+      break;
+    default:
+      push_token(tok);
+      break;
+    }
+
+    if (kind != op_t::LAST) {
+      ptr_op_t prev(node);
+      node = new op_t(kind);
+      node->set_left(prev);
+      node->set_right(parse_add_expr(in, _flags));
+
+      if (! node->right())
+	throw_(parse_error,
+	       tok.symbol << " operator not followed by argument");
+    }
+  }
+
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_and_expr(std::istream& in,
+				 const flags_t tflags) const
+{
+  ptr_op_t node(parse_logic_expr(in, tflags));
+
+  if (node) {
+    token_t& tok = next_token(in, tflags);
+
+    if (tok.kind == token_t::KW_AND) {
+      ptr_op_t prev(node);
+      node = new op_t(op_t::O_AND);
+      node->set_left(prev);
+      node->set_right(parse_and_expr(in, tflags));
+      if (! node->right())
+	throw_(parse_error,
+	       tok.symbol << " operator not followed by argument");
+    } else {
+      push_token(tok);
+    }
+  }
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_or_expr(std::istream& in,
+				const flags_t tflags) const
+{
+  ptr_op_t node(parse_and_expr(in, tflags));
+
+  if (node) {
+    token_t& tok = next_token(in, tflags);
+
+    if (tok.kind == token_t::KW_OR) {
+      ptr_op_t prev(node);
+      node = new op_t(op_t::O_OR);
+      node->set_left(prev);
+      node->set_right(parse_or_expr(in, tflags));
+      if (! node->right())
+	throw_(parse_error,
+	       tok.symbol << " operator not followed by argument");
+    } else {
+      push_token(tok);
+    }
+  }
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse_value_expr(std::istream& in,
+				   const flags_t tflags) const
+{
+  ptr_op_t node(parse_or_expr(in, tflags));
+
+  if (node) {
+    token_t& tok = next_token(in, tflags);
+
+    if (tok.kind == token_t::COMMA) {
+      ptr_op_t prev(node);
+      node = new op_t(op_t::O_COMMA);
+      node->set_left(prev);
+      node->set_right(parse_value_expr(in, tflags));
+      if (! node->right())
+	throw_(parse_error,
+	       tok.symbol << " operator not followed by argument");
+      tok = next_token(in, tflags);
+    }
+
+    if (tok.kind != token_t::TOK_EOF) {
+      if (tflags & EXPR_PARSE_PARTIAL)
+	push_token(tok);
+      else
+	tok.unexpected();
+    }
+  }
+  else if (! (tflags & EXPR_PARSE_PARTIAL)) {
+    throw_(parse_error, "Failed to parse value expression");
+  }
+
+  return node;
+}
+
+expr_t::ptr_op_t
+expr_t::parser_t::parse(std::istream& in, const flags_t flags)
+{
+#if 0
+  try {
+#endif
+    ptr_op_t top_node = parse_value_expr(in, flags);
+
+    if (use_lookahead) {
+      use_lookahead = false;
+      lookahead.rewind(in);
+    }
+    lookahead.clear();
+
+    return top_node;
+#if 0
+  }
+  catch (error * err) {
+    err->context.push_back
+      (new line_context(str, (long)in.tellg() - 1,
+			"While parsing value expression:"));
+    throw err;
+  }
+#endif
+}
+
+} // namespace ledger