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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "interpreter.h"
#include "inter_builtins.h"
#include "util.h"
int namehash(const char *name,int mod){
int h=0;
for(int i=0;name[i];i++)h+=name[i];
return h%mod;
}
#define VMAP_HASHSZ (61)
typedef struct Vllist{
char *name;
AST *value;
struct Vllist *next;
} Vllist;
typedef struct Scope{
Vllist *vmap[VMAP_HASHSZ];
struct Scope *next;
} Scope;
typedef struct Symbolstore{
int sz,len;
char **syms;
} Symbolstore;
struct InterState{
Scope *scope;
Symbolstore ss;
};
Scope* scope_make(void){
Scope *scope=malloc(1,Scope);
memset(scope->vmap,0,VMAP_HASHSZ*sizeof(Vllist*));
scope->next=NULL;
return scope;
}
InterState* inter_make(void){
InterState *is=malloc(1,InterState);
is->scope=scope_make();
is->ss.sz=16;
is->ss.len=0;
is->ss.syms=malloc(is->ss.sz,char*);
return is;
}
static void scope_destroy(Scope *scope,bool recursive){
do {
for(int i=0;i<VMAP_HASHSZ;i++){
while(scope->vmap[i]){
Vllist *ll=scope->vmap[i];
free(ll->name);
ast_free(ll->value);
scope->vmap[i]=ll->next;
free(ll);
}
}
Scope *next=scope->next;
free(scope);
scope=next;
} while(recursive&&scope);
}
void inter_destroy(InterState *is){
assert(is);
scope_destroy(is->scope,true);
for(int i=0;i<is->ss.len;i++)free(is->ss.syms[i]);
free(is->ss.syms);
}
static void intern_symbols(InterState *is,AST *ast){
switch(ast->type){
case AST_LIST:
for(int i=0;i<ast->li.len;i++)intern_symbols(is,ast->li.nodes[i]);
break;
case AST_SYMBOL:{
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->sy.name)==0)break;
}
if(i<is->ss.len){
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->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);
InterRet ir=nodes[0]->la.cfunc(is,ast->li.len-1,nodes+1);
for(int i=0;i<ast->li.len;i++)ast_free(nodes[i]);
return ir;
}
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_assign(InterState *is,const char *name,AST *ast){
assert(is->scope);
int h=namehash(name,VMAP_HASHSZ);
Vllist *ll=malloc(1,Vllist);
ll->name=copystring(name);
ll->value=ast;
ll->next=is->scope->vmap[h];
is->scope->vmap[h]=ll;
}
void inter_register(InterState *is,const char *name,lambdafunc_t cfunc){
inter_assign(is,name,ast_lambda(cfunc,NULL));
}
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);
inter_register(is,"define",builtin_define);
}
InterRet inter_runcode(InterState *is,AST *ast){
intern_symbols(is,ast);
return interpret(is,ast);
}
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