From cac651cd88f8da1e5957b0cc13fa25d79e1887fc Mon Sep 17 00:00:00 2001
From: tomsmeding <tom.smeding@gmail.com>
Date: Tue, 23 Aug 2016 20:58:50 +0200
Subject: Many things

- two-letter AST union members
- AST_QUOTED
- AST_LAMBDA
- an interpreter that works
- function registering in the interpreter
- some builtins
---
 interpreter.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 119 insertions(+), 6 deletions(-)

(limited to 'interpreter.c')

diff --git a/interpreter.c b/interpreter.c
index 333b8c9..05e5d2c 100644
--- a/interpreter.c
+++ b/interpreter.c
@@ -4,6 +4,7 @@
 #include <assert.h>
 
 #include "interpreter.h"
+#include "inter_builtins.h"
 #include "util.h"
 
 
@@ -85,36 +86,148 @@ void inter_destroy(InterState *is){
 static void intern_symbols(InterState *is,AST *ast){
 	switch(ast->type){
 		case AST_LIST:
-			for(int i=0;i<ast->l.len;i++)intern_symbols(is,ast->l.nodes[i]);
+			for(int i=0;i<ast->li.len;i++)intern_symbols(is,ast->li.nodes[i]);
 			break;
 
 		case AST_SYMBOL:{
-			if(ast->s.symid>=0&&ast->s.symid<is->ss.len&&strcmp(ast->s.name,is->ss.syms[ast->s.symid])==0){
+			if(ast->sy.symid>=0&&ast->sy.symid<is->ss.len&&strcmp(ast->sy.name,is->ss.syms[ast->sy.symid])==0){
 				break;
 			}
 			int i;
 			for(i=0;i<is->ss.len;i++){
-				if(strcmp(is->ss.syms[i],ast->s.name)==0)break;
+				if(strcmp(is->ss.syms[i],ast->sy.name)==0)break;
 			}
 			if(i<is->ss.len){
-				ast->s.symid=i;
+				ast->sy.symid=i;
 				break;
 			}
 			if(is->ss.len==is->ss.sz){
 				is->ss.sz*=2;
 				is->ss.syms=realloc(is->ss.syms,is->ss.sz,char*);
 			}
-			is->ss.syms[is->ss.len++]=copystring(ast->s.name);
+			is->ss.syms[is->ss.len++]=copystring(ast->sy.name);
 			break;
 		}
 
+		case AST_QUOTED:
+			intern_symbols(is,ast->qu.ast);
+			break;
+
 		case AST_WORD:
 		case AST_NUMBER:
 		case AST_STRING:
 			break;
+
+		default:
+			assert(false);
+	}
+}
+
+static const AST* find_var(const InterState *is,const char *name){
+	int h=namehash(name,VMAP_HASHSZ);
+	for(const Scope *scope=is->scope;scope;scope=scope->next){
+		for(const Vllist *ll=scope->vmap[h];ll;ll=ll->next){
+			if(strcmp(name,ll->name)==0)return ll->value;
+		}
+	}
+	return NULL;
+}
+
+InterRet ir_ast(AST *ast){
+	InterRet ir={ast,NULL};
+	return ir;
+}
+
+InterRet ir_err(char *errstr){
+	InterRet ir={NULL,errstr};
+	return ir;
+}
+
+InterRet ir_err_c(const char *errstr){
+	return ir_err(copystring(errstr));
+}
+
+static InterRet interpret(InterState *is,const AST *ast){
+	switch(ast->type){
+		case AST_LIST:{
+			if(ast->li.len==0){
+				return ir_ast(ast_copy(ast));
+			}
+			assert(ast->li.len>0);
+			AST *nodes[ast->li.len];
+			for(int i=0;i<ast->li.len;i++){
+				InterRet ir=interpret(is,ast->li.nodes[i]);;
+				if(ir.errstr){
+					while(i-->0)ast_free(nodes[i]);
+					return ir;
+				}
+				nodes[i]=ir.ast;
+			}
+
+			if(nodes[0]->type!=AST_LAMBDA){
+				fprintf(stderr,"type = %d\n",nodes[0]->type);
+				return ir_err_c("First node in evaluated list not a function");
+			}
+
+#define NOT_IMPLEMENTED false
+			if(nodes[0]->la.body)assert(NOT_IMPLEMENTED);
+
+			return nodes[0]->la.cfunc(is,ast->li.len-1,nodes+1);
+		}
+
+		case AST_SYMBOL:
+			return ir_ast(ast_copy(ast));
+
+		case AST_WORD:{
+			const AST *cv=find_var(is,ast->wo.word);
+			if(cv)return ir_ast(ast_copy(cv));
+			char *errstr;
+			asprintf(&errstr,"Unknown variable '%s'",ast->wo.word);
+			if(!errstr)outofmem();
+			return ir_err(errstr);
+		}
+
+		case AST_NUMBER:
+			return ir_ast(ast_copy(ast));
+
+		case AST_STRING:
+			return ir_ast(ast_copy(ast));
+
+		case AST_QUOTED:
+			return ir_ast(ast_copy(ast->qu.ast));
+
+		default:
+			assert(false);
 	}
 }
 
-void inter_runcode(InterState *is,AST *ast){
+void inter_register(InterState *is,const char *name,lambdafunc_t cfunc){
+	assert(is->scope);
+	int h=namehash(name,VMAP_HASHSZ);
+	Vllist *ll=malloc(1,Vllist);
+	ll->name=copystring(name);
+	ll->value=ast_lambda(cfunc,NULL);
+	ll->next=is->scope->vmap[h];
+	is->scope->vmap[h]=ll;
+}
+
+void inter_register_prelude(InterState *is){
+	inter_register(is,"do",builtin_do);
+	inter_register(is,"print",builtin_print);
+	inter_register(is,"+",builtin_sum);
+	inter_register(is,"-",builtin_difference);
+	inter_register(is,"*",builtin_product);
+	inter_register(is,"/",builtin_quotient);
+	inter_register(is,"%",builtin_remainder);
+	inter_register(is,"sum",builtin_sum);
+	inter_register(is,"difference",builtin_difference);
+	inter_register(is,"product",builtin_product);
+	inter_register(is,"quotient",builtin_quotient);
+	inter_register(is,"remainder",builtin_remainder);
+}
+
+InterRet inter_runcode(InterState *is,AST *ast){
 	intern_symbols(is,ast);
+
+	return interpret(is,ast);
 }
-- 
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