From 9a938d3ce26b2d3728d791c0f858acdbd50223b5 Mon Sep 17 00:00:00 2001
From: Peter Mikkelsen <petermikkelsen10@gmail.com>
Date: Sun, 23 Jan 2022 21:16:02 +0000
Subject: =?UTF-8?q?Rework=20symbol=20lookup=20to=20use=20lexical=20scoping?=
 =?UTF-8?q?,=20and=20implement=20recursive=20function=20call=20via=20?=
 =?UTF-8?q?=E2=88=87?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 symbol.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 96 insertions(+), 8 deletions(-)

(limited to 'symbol.c')

diff --git a/symbol.c b/symbol.c
index d51a730..e67f043 100644
--- a/symbol.c
+++ b/symbol.c
@@ -5,15 +5,29 @@
 #include "apl9.h"
 
 Symtab *globalsymtab;
-Symtab *currentsymtab;
+DfnFrame *currentdfn;
+
+Symtab *newsymtab(void);
+void freesymtab(Symtab *);
 
 Symbol *
-getsym(Symtab *tab, Rune *name)
+getsym(Rune *name)
 {
-	for(int i = 0; i < tab->nsyms; i++)
-		if(runestrcmp(tab->syms[i]->name, name) == 0)
-			return tab->syms[i];
-	
+	DfnFrame *dfn = currentdfn;
+	Symtab *tab;
+	do{
+		if(dfn != nil)
+			tab = dfn->symtab;
+		else
+			tab = globalsymtab;
+
+		for(int i = 0; i < tab->nsyms; i++)
+			if(runestrcmp(tab->syms[i]->name, name) == 0)
+				return tab->syms[i];
+		if(dfn)
+			dfn = dfn->prev;
+	}while(dfn != nil);
+
 	tab->nsyms++;
 	tab->syms = realloc(tab->syms, sizeof(Symbol *) * tab->nsyms);
 	tab->syms[tab->nsyms-1] = emalloc(sizeof(Symbol));
@@ -30,8 +44,8 @@ newsymtab(void)
 	Symtab *tab = emalloc(sizeof(Symtab));
 	tab->nsyms = 0;
 	tab->syms = nil;
-	tab->io = currentsymtab ? currentsymtab->io : 1;
-	tab->div = currentsymtab ? currentsymtab->div : 0;
+	tab->io = globalIO();
+	tab->div = globalDIV();
 
 	return tab;
 }
@@ -48,3 +62,77 @@ freesymtab(Symtab *tab)
 	free(tab->syms);
 	free(tab);
 }
+
+void
+initsymtab(void)
+{
+	globalsymtab = newsymtab();
+}
+
+DfnFrame *
+getcurrentdfn(void)
+{
+	return currentdfn;
+}
+
+DfnFrame *
+pushdfnframe(Rune *code)
+{
+	DfnFrame *new = malloc(sizeof(DfnFrame));
+	new->code = code;
+	new->symtab = newsymtab();
+	new->prev = currentdfn;
+	currentdfn = new;
+	return new;
+}
+
+void
+popdfnframe(void)
+{
+	if(currentdfn != nil){
+		DfnFrame *prev = currentdfn->prev;
+		freesymtab(currentdfn->symtab);
+		free(currentdfn);
+		currentdfn = prev;
+	}
+}
+
+vlong
+globalIO(void)
+{
+	if(currentdfn)
+		return currentdfn->symtab->io;
+	else if(globalsymtab)
+		return globalsymtab->io;
+	else
+		return 1;
+}
+
+void
+globalIOset(vlong io)
+{
+	if(currentdfn)
+		currentdfn->symtab->io = io;
+	else
+		globalsymtab->io = io;
+}
+
+int
+globalDIV(void)
+{
+	if(currentdfn)
+		return currentdfn->symtab->div;
+	else if(globalsymtab)
+		return globalsymtab->div;
+	else
+		return 0;
+}
+
+void
+globalDIVset(int div)
+{
+	if(currentdfn)
+		currentdfn->symtab->div = div;
+	else
+		globalsymtab->div = div;
+}
\ No newline at end of file
-- 
cgit v1.2.3