diff options
Diffstat (limited to 'src/macros.cpp')
| -rw-r--r-- | src/macros.cpp | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/src/macros.cpp b/src/macros.cpp new file mode 100644 index 00000000..4356a399 --- /dev/null +++ b/src/macros.cpp @@ -0,0 +1,143 @@ +/*
+ */
+#include "common.hpp"
+#include "macros.hpp"
+#include "parse/parseerror.hpp"
+#include "parse/tokentree.hpp"
+#include "parse/common.hpp"
+
+typedef ::std::map< ::std::string, MacroRules> t_macro_regs;
+
+t_macro_regs g_macro_registrations;
+
+void Macro_InitDefaults()
+{
+ // try!() macro
+ {
+ MacroRule rule;
+ rule.m_pattern.push_back( MacroPatEnt("val", MacroPatEnt::PAT_EXPR) );
+ // match $rule {
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_RWORD_MATCH)) );
+ rule.m_contents.push_back( MacroRuleEnt("val") );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_BRACE_OPEN)) );
+ // Ok(v) => v,
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "Ok")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_PAREN_OPEN)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "v")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_PAREN_CLOSE)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_FATARROW)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "v")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_COMMA)) );
+ // Err(e) => return Err(r),
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "Err")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_PAREN_OPEN)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "e")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_PAREN_CLOSE)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_FATARROW)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_RWORD_RETURN)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "Err")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_PAREN_OPEN)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_IDENT, "e")) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_PAREN_CLOSE)) );
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_COMMA)) );
+ // }
+ rule.m_contents.push_back( MacroRuleEnt(Token(TOK_BRACE_CLOSE)) );
+ MacroRules rules;
+ rules.push_back(rule);
+ g_macro_registrations.insert( make_pair(::std::string("try"), rules));
+ }
+}
+
+MacroExpander Macro_Invoke(const char* name, TokenTree input)
+{
+ // XXX: EVIL HACK! - This should be removed when std loading is implemented
+ if( g_macro_registrations.size() == 0 ) {
+ Macro_InitDefaults();
+ }
+ // 1. Locate macro with that name
+ t_macro_regs::iterator macro_reg = g_macro_registrations.find(name);
+ if( macro_reg != g_macro_registrations.end() )
+ {
+ const MacroRules& rules = macro_reg->second;
+ // 2. Check input token tree against possible variants
+ // 3. Bind names
+ // 4. Return expander
+ FOREACH(MacroRules, rule_it, rules)
+ {
+ Token tok;
+ // Create token stream for input tree
+ TTStream lex(input);
+ if(GET_TOK(tok, lex) == TOK_EOF) {
+ throw ParseError::Unexpected(tok);
+ }
+ ::std::map<const char*,TokenTree,cmp_str> bound_tts;
+ // Parse according to rules
+ bool fail = false;
+ FOREACH(::std::vector<MacroPatEnt>, pat_it, rule_it->m_pattern)
+ {
+ TokenTree val;
+ const MacroPatEnt& pat = *pat_it;
+ try
+ {
+ switch(pat.type)
+ {
+ case MacroPatEnt::PAT_TOKEN:
+ GET_CHECK_TOK(tok, lex, pat.tok.type());
+ break;
+ case MacroPatEnt::PAT_EXPR:
+ val = Parse_TT_Expr(lex);
+ if(0)
+ case MacroPatEnt::PAT_STMT:
+ val = Parse_TT_Stmt(lex);
+ bound_tts.insert( std::make_pair(pat.name.c_str(), val) );
+ break;
+ default:
+ throw ParseError::Todo("macro pattern matching");
+ }
+ }
+ catch(const ParseError::Base& e)
+ {
+ fail = true;
+ break;
+ }
+ }
+ // TODO: Actually check if the final token is the closer to the first
+ if( !fail && GET_TOK(tok, lex) == TOK_EOF) {
+ throw ParseError::Unexpected(tok);
+ }
+ if( !fail && lex.getToken().type() == TOK_EOF )
+ {
+ return MacroExpander(rule_it->m_contents, bound_tts);
+ }
+ }
+ throw ParseError::Todo("Error when macro fails to match");
+ }
+
+ throw ParseError::Generic( ::std::string("Macro '") + name + "' was not found" );
+}
+
+Token MacroExpander::realGetToken()
+{
+ if( m_ttstream.get() )
+ {
+ Token rv = m_ttstream->getToken();
+ if( rv.type() != TOK_EOF )
+ return rv;
+ m_ttstream.reset();
+ }
+ if( m_ofs < m_contents.size() )
+ {
+ const MacroRuleEnt& ent = m_contents[m_ofs];
+ m_ofs ++;
+ if( ent.name.size() != 0 ) {
+ // Binding!
+ m_ttstream.reset( new TTStream(m_mappings.at(ent.name.c_str())) );
+ return m_ttstream->getToken();
+ }
+ else {
+ return ent.tok;
+ }
+ throw ParseError::Todo("MacroExpander - realGetToken");
+ }
+ return Token(TOK_EOF);
+}
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