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Added S-expressions

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This commit is contained in:
Brandon Rozek 2018-06-03 22:54:10 -04:00
parent 36a0542b80
commit 47fbb7ab68
1 changed files with 299 additions and 181 deletions
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478
prompt.c
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@ -30,36 +30,50 @@ void add_history(char* unused) {}
#include <editline/readline.h> #include <editline/readline.h>
#endif #endif
typedef union numerr { typedef union typeval {
long num; long num;
double dec; double dec;
int err; } TypeVal;
} NumErr;
// A lispy value can either be a number or an error // A lispy value can either be a number or an error
typedef struct { typedef struct lval {
int type; int type;
NumErr data; TypeVal data;
// Error and symbols contain string data
char* err;
char* sym;
// Count and pointer to a list of lval*
int count;
struct lval** cell;
} lval; } lval;
// Possible lispy value types // Possible lispy value types
enum { LVAL_LONG, LVAL_DOUBLE, LVAL_ERR }; enum { LVAL_ERR, LVAL_LONG, LVAL_DOUBLE, LVAL_SYM, LVAL_SEXPR };
// Possible Error Types
enum { LERR_DIV_ZERO, LERR_BAD_OP, LERR_BAD_NUM, LERR_BAD_ARG };
lval eval_uni(lval x, char* op);
lval eval_op(lval x, char* op, lval y);
lval eval(mpc_ast_t* t);
double max(double x, double y); double max(double x, double y);
double min(double x, double y); double min(double x, double y);
lval lval_long(long x); lval* lval_long(long x);
lval lval_double(double x); lval* lval_double(double x);
lval lval_err(int x); lval* lval_err(char* m);
void flval_print(FILE* stream, lval v); lval* lval_sym(char* s);
void lval_print(lval v); lval* lval_sexpr(void);
void lval_println(lval v); double lval_getData(lval* x);
void lval_updateData(lval* x, double val, int type);
void lval_del(lval* v);
lval* lval_read_long(mpc_ast_t* t);
lval* lval_read_double(mpc_ast_t* t);
lval* lval_read(mpc_ast_t* t);
lval* lval_add(lval* v, lval* x);
lval* lval_eval_sexpr(lval* v);
lval* lval_eval(lval* v);
lval* lval_take(lval* v, int i);
lval* lval_pop(lval* v, int i);
lval* builtin_op(lval* v, char* op);
void flval_print(FILE* stream, lval* v);
void lval_print(lval* v);
void lval_println(lval* v);
size_t treeContentsLength(mpc_ast_t* t); size_t treeContentsLength(mpc_ast_t* t);
char* concatTreeContents(mpc_ast_t* t); char* concatTreeContents(mpc_ast_t* t);
void concatNodeContents(char* stringToExtend, mpc_ast_t* t, size_t* currentLength); void concatNodeContents(char* stringToExtend, mpc_ast_t* t, size_t* currentLength);
@ -70,21 +84,23 @@ int main (int argc, char** argv) {
mpc_parser_t* Number = mpc_new("number"); mpc_parser_t* Number = mpc_new("number");
mpc_parser_t* Long = mpc_new("long"); mpc_parser_t* Long = mpc_new("long");
mpc_parser_t* Double = mpc_new("double"); mpc_parser_t* Double = mpc_new("double");
mpc_parser_t* Operator = mpc_new("operator"); mpc_parser_t* Symbol = mpc_new("symbol");
mpc_parser_t* Sexpr = mpc_new("sexpr");
mpc_parser_t* Expr = mpc_new("expr"); mpc_parser_t* Expr = mpc_new("expr");
mpc_parser_t* Lispy = mpc_new("lispy"); mpc_parser_t* Lispy = mpc_new("lispy");
// Define them with the following language // Define them with the following language
mpca_lang(MPCA_LANG_DEFAULT, mpca_lang(MPCA_LANG_DEFAULT,
"\ "\
number : /[0-9]+/; \ number : /[0-9]+/; \
long : '-'? <number>; \ long : /-?[0-9]+/; \
double : <long> '.' <number>; \ double : <long> '.' <number>; \
operator : '+' | '-' | '*' | '/' | '%' \ symbol : '+' | '-' | '*' | '/' | '%' \
| '^' | \"min\" | \"max\"; \ | '^' | \"min\" | \"max\"; \
expr : (<double> | <long>) | '(' <operator> <expr>+ ')'; \ sexpr : '(' <expr>* ')'; \
lispy : /^/ <operator> <expr>+ /$/; \ expr : (<double> | <long>) | <symbol> | <sexpr>; \
", Number, Long, Double, Operator, Expr, Lispy); lispy : /^/ <expr>* /$/; \
", Number, Long, Double, Symbol, Sexpr, Expr, Lispy);
@ -103,13 +119,12 @@ int main (int argc, char** argv) {
// Attempt to parse the user input // Attempt to parse the user input
mpc_result_t r; mpc_result_t r;
if (mpc_parse("<stdin>", input, Lispy, &r)) { if (mpc_parse("<stdin>", input, Lispy, &r)) {
// On success print the abstract syntax tree
//mpc_ast_print(r.output);
// Evualuate the expression and print its output // Evualuate the expression and print its output
lval result = eval(r.output); // lval result = eval(r.output);
lval* result = lval_eval(lval_read(r.output));
lval_println(result); lval_println(result);
// mpc_ast_print(r.output); lval_del(result);
mpc_ast_print(r.output);
mpc_ast_delete(r.output); mpc_ast_delete(r.output);
} else { } else {
// Otherwise print the error // Otherwise print the error
@ -121,124 +136,10 @@ int main (int argc, char** argv) {
free(input); free(input);
} }
mpc_cleanup(6, Number, Long, Double, Operator, Expr, Lispy); mpc_cleanup(7, Number, Long, Double, Symbol, Sexpr, Expr, Lispy);
return 0; return 0;
} }
lval eval_op(lval x, char* op, lval y) {
if (x.type == LVAL_ERR) { return x; }
if (y.type == LVAL_ERR) { return y; }
int resultType;
if (x.type == LVAL_LONG && y.type == LVAL_LONG) {
resultType = LVAL_LONG;
} else {
resultType = LVAL_DOUBLE;
}
double xVal;
if (x.type == LVAL_LONG) {
xVal = x.data.num;
} else {
xVal = x.data.dec;
}
double yVal;
if (y.type == LVAL_LONG) {
yVal = y.data.num;
} else {
yVal = y.data.dec;
}
if (strcmp(op, "+") == 0) {
return (resultType == LVAL_LONG) ? lval_long(xVal + yVal) : lval_double(xVal + yVal);
}
if (strcmp(op, "-") == 0) {
return (resultType == LVAL_LONG) ? lval_long(xVal - yVal) : lval_double(xVal - yVal);
}
if (strcmp(op, "*") == 0) {
return (resultType == LVAL_LONG) ? lval_long(xVal * yVal) : lval_double(xVal * yVal);;
}
if (strcmp(op, "/") == 0) {
if (yVal == 0) { return lval_err(LERR_DIV_ZERO); }
return (resultType == LVAL_LONG) ? lval_long(xVal / yVal) : lval_double(xVal / yVal);
}
if (strcmp(op, "min") == 0) {
return (resultType == LVAL_LONG) ? lval_long(min(xVal, yVal)) : lval_double(min(xVal, yVal));
}
if (strcmp(op, "max") == 0) {
return (resultType == LVAL_LONG) ? lval_long(max(xVal, yVal)) : lval_double(max(xVal, yVal));
}
if (strcmp(op, "^") == 0) {
return (resultType == LVAL_LONG) ? lval_long(pow(xVal, yVal)) : lval_double(pow(xVal, yVal));
}
if (strcmp(op, "%") == 0) {
return (resultType == LVAL_LONG) ? lval_long(fmod(xVal, yVal)) : lval_double(fmod(xVal, yVal));
}
return lval_err(LERR_BAD_OP);
}
lval eval_uni(lval x, char* op) {
// If it's an error, return it
if (x.type == LVAL_ERR) { return x; }
double xVal = (x.type == LVAL_LONG) ? x.data.num : x.data.dec;
if (strcmp(op, "-") == 0) { return (x.type == LVAL_LONG) ? lval_long(-1 * xVal) : lval_double(-1 * xVal); }
return lval_err(LERR_BAD_OP);
}
lval eval(mpc_ast_t* t) {
if (strstr(t->tag, "long")) {
// Grab the contents of all the nodes in the tree otherwise you might not get the string you expect
char* treeString = concatTreeContents(t);
// Check to see if there's some error in conversion
errno = 0;
long x = strtol(treeString, NULL, 10);
// Free the memory allocated in treestring since it's no longer needed
free(treeString);
return errno != ERANGE ? lval_long(x) : lval_err(LERR_BAD_NUM);
}
if (strstr(t->tag, "double")) {
char* treeString = concatTreeContents(t);
// Check to see if there's some error in conversion
errno = 0;
double x = strtod(treeString, NULL);
free(treeString);
return errno != ERANGE ? lval_double(x) : lval_err(LERR_BAD_NUM);
}
// The operator is always the second child
char* op = t->children[1]->contents;
// We store the third child in x
lval x = eval(t->children[2]);
// If there is only one operand, apply a uniary operation
if (t->children_num == 4) {
return eval_uni(x, op);
}
// Iterate over the remaining children and reduce
int i = 3;
while (strstr(t->children[i]->tag, "expr")) {
x = eval_op(x, op, eval(t->children[i]));
i++;
}
return x;
}
double max(double x, double y) { double max(double x, double y) {
if (x > y) { if (x > y) {
@ -254,54 +155,155 @@ double min(double x, double y) {
return y; return y;
} }
lval lval_long(long x) { lval* lval_long(long x) {
lval v; lval* v = malloc(sizeof(lval));
v.type = LVAL_LONG; v->type = LVAL_LONG;
v.data.num = x; v->data.num = x;
return v; return v;
} }
lval lval_double(double x) { lval* lval_double(double x) {
lval v; lval* v = malloc(sizeof(lval));
v.type = LVAL_DOUBLE; v->type = LVAL_DOUBLE;
v.data.dec = x; v->data.dec = x;
return v; return v;
} }
lval lval_err(int x) { lval* lval_err(char* m) {
lval v; lval* v = malloc(sizeof(lval));
v.type = LVAL_ERR; v->type = LVAL_ERR;
v.data.err = x; v->err = malloc(strlen(m) + 1);
strcpy(v->err, m);
return v; return v;
} }
void flval_print(FILE* stream, lval v) { lval* lval_sym(char* s) {
switch (v.type) { lval* v = malloc(sizeof(lval));
v->type = LVAL_SYM;
v->sym = malloc(strlen(s) + 1);
strcpy(v->sym, s);
return v;
}
lval* lval_sexpr(void) {
lval* v = malloc(sizeof(lval));
v->type = LVAL_SEXPR;
v->count = 0;
v->cell = NULL;
return v;
}
void lval_del(lval* v) {
switch (v->type) {
case LVAL_LONG: break;
case LVAL_DOUBLE: break;
// Free the string data
case LVAL_ERR: free(v->err); break;
case LVAL_SYM: free(v->sym); break;
// Delete all elements inside SEXPR
case LVAL_SEXPR:
for (int i = 0; i < v->count; i++) {
lval_del(v->cell[i]);
}
// Also free the memory allocated to contain the pointers
free(v->cell);
break;
}
// // Free the memory allocated for the lval struct itself
free(v);
}
lval* lval_read_long(mpc_ast_t* t) {
// Grab the contents of all the nodes in the tree otherwise you might not get the string you expect
char* treeString = concatTreeContents(t);
// Check to see if there's some error in conversion
errno = 0;
long x = strtol(treeString, NULL, 10);
// Free the memory allocated in treestring since it's no longer needed
free(treeString);
return errno != ERANGE ? lval_long(x) : lval_err("Invalid Number");
}
lval* lval_read_double(mpc_ast_t* t) {
char* treeString = concatTreeContents(t);
// Check to see if there's some error in conversion
errno = 0;
double x = strtod(treeString, NULL);
free(treeString);
return errno != ERANGE ? lval_double(x) : lval_err("Invalid Number");
}
lval* lval_read(mpc_ast_t* t) {
// If symbol or number, convert
if (strstr(t->tag, "long")) { return lval_read_long(t); }
if (strstr(t->tag, "double")) { return lval_read_double(t); }
if (strstr(t->tag, "symbol")) { return lval_sym(t->contents); }
// If root or sexpr, then create an empty list
lval* x = NULL;
if (strcmp(t->tag, ">") == 0 || strstr(t->tag, "sexpr")) {
x = lval_sexpr();
}
// Fill the list with any valid expression contained
for (int i = 0; i < t->children_num; i++) {
if (strcmp(t->children[i]->contents, "(") == 0) { continue; }
if (strcmp(t->children[i]->contents, ")") == 0) { continue; }
if (strcmp(t->children[i]->tag, "regex") == 0) { continue; }
x = lval_add(x, lval_read(t->children[i]));
}
return x;
}
lval* lval_add(lval* v, lval* x) {
v->count++;
v->cell = realloc(v->cell, sizeof(lval*) * v->count);
v->cell[v->count - 1] = x;
return v;
}
void flval_expr_print(FILE* stream, lval* v, char open, char close) {
putchar(open);
for (int i = 0; i < v->count; i++) {
// Print value contained within
flval_print(stream, v->cell[i]);
// Put a trailing whitespace unless its the last element
if (i != (v->count - 1)) {
putchar(' ');
}
}
putchar(close);
}
void flval_print(FILE* stream, lval* v) {
switch (v->type) {
// If it's an integer, then print it out // If it's an integer, then print it out
case LVAL_LONG: fprintf(stream, "%li", v.data.num); break; case LVAL_LONG: fprintf(stream, "%li", v->data.num); break;
// Do the same for doubles case LVAL_DOUBLE: fprintf(stream, "%lf", v->data.dec); break;
case LVAL_DOUBLE: fprintf(stream, "%lf", v.data.dec); break;
// If it's an error, indicate the error case LVAL_ERR: fprintf(stream, "Error: %s", v->err); break;
case LVAL_ERR:
fprintf(stream, "Error: "); case LVAL_SYM: fprintf(stream, "%s", v->sym); break;
if (v.data.err == LERR_DIV_ZERO) {
fprintf(stream, "Division by zero"); case LVAL_SEXPR: flval_expr_print(stream, v, '(', ')'); break;
}
if (v.data.err == LERR_BAD_OP) {
fprintf(stream, "Invalid Operator");
}
if (v.data.err == LERR_BAD_NUM) {
fprintf(stream, "Invalid Number");
}
break;
} }
} }
void lval_print(lval v) { flval_print(stdout, v); } void lval_print(lval* v) { flval_print(stdout, v); }
void lval_println(lval v) { lval_print(v); putchar('\n'); } void lval_println(lval* v) { lval_print(v); putchar('\n'); }
size_t treeContentsLength(mpc_ast_t* t) { size_t treeContentsLength(mpc_ast_t* t) {
size_t result = strlen(t->contents); size_t result = strlen(t->contents);
@ -344,3 +346,119 @@ void concatNodeContents(char* stringToExtend, mpc_ast_t* t, size_t* currentLengt
} }
} }
lval* lval_eval_sexpr(lval* v) {
// Evaluate children
for (int i = 0; i < v->count; i++) {
v->cell[i] = lval_eval(v->cell[i]);
}
// Error checking [If there's an error, return it]
for (int i = 0; i < v->count; i++) {
if (v->cell[i]->type == LVAL_ERR) { return lval_take(v, i); }
}
// Empty expression
if (v->count == 0) { return v; }
// Single expression
if (v->count == 1) { return lval_take(v, 0); }
// Ensure first element is a symbol otherwise
lval* f = lval_pop(v, 0);
if (f->type != LVAL_SYM) {
printf("The type of f is %d\n", f->type);
lval_del(f); lval_del(v);
return lval_err("S-expression does not start with symbol");
}
lval* result = builtin_op(v, f->sym);
lval_del(f);
return result;
}
lval* lval_eval(lval* v) {
// Evauluate sexpressions
if (v->type == LVAL_SEXPR) { return lval_eval_sexpr(v); }
// All other lval types remail the same
return v;
}
lval* lval_pop(lval* v, int i) {
// Find the item at i
lval* x = v->cell[i];
// Shift the memory after the item i over the top
memmove(&v->cell[i], &v->cell[i + 1], sizeof(lval*) * (v->count - i - 1));
// Decrease the count of items in the list
v->count--;
// Reallocate the memory used
v->cell = realloc(v->cell, sizeof(lval*) * v->count);
return x;
}
lval* lval_take(lval* v, int i) {
lval* x = lval_pop(v, i);
lval_del(v);
return x;
}
lval* builtin_op(lval* a, char* op) {
// Ensure all arguments are numbers
for (int i = 0; i < a->count; i++) {
if (a->cell[i]->type != LVAL_LONG && a->cell[i]->type != LVAL_DOUBLE) {
lval_del(a);
return lval_err("Cannot run operation on non-number");
}
}
// Pop the first element
lval* x = lval_pop(a, 0);
// If there are no other arguments then perform unary operation
if (a->count == 0) {
if (strcmp(op, "-") == 0) { lval_updateData(x, -1 * lval_getData(x), x->type); }
}
while (a->count > 0) {
// Pop the next element
lval* y = lval_pop(a, 0);
int resultType = (x->type == LVAL_LONG && y->type == LVAL_LONG) ? LVAL_LONG : LVAL_DOUBLE;
if (strcmp(op, "+") == 0) { lval_updateData(x, lval_getData(x) + lval_getData(y), resultType); }
if (strcmp(op, "-") == 0) { lval_updateData(x, lval_getData(x) - lval_getData(y), resultType); }
if (strcmp(op, "*") == 0) { lval_updateData(x, lval_getData(x) * lval_getData(y), resultType); }
if (strcmp(op, "/") == 0) {
if (lval_getData(y) == 0) { return lval_err("Divide by Zero"); }
lval_updateData(x, lval_getData(x) / lval_getData(y), resultType);
}
if (strcmp(op, "min") == 0) { lval_updateData(x, min(lval_getData(x), lval_getData(y)), resultType); }
if (strcmp(op, "max") == 0) { lval_updateData(x, max(lval_getData(x), lval_getData(y)), resultType); }
if (strcmp(op, "^") == 0) { lval_updateData(x, pow(lval_getData(x), lval_getData(y)), resultType); }
if (strcmp(op, "%") == 0) { lval_updateData(x, fmod(lval_getData(x), lval_getData(y)), resultType); }
lval_del(y);
}
lval_del(a);
return x;
}
double lval_getData(lval* x) {
if (x->type == LVAL_LONG) {
return x->data.num;
}
return x->data.dec;
}
void lval_updateData(lval* x, double val, int type) {
if (type == LVAL_LONG) {
x->data.num = val;
return;
}
x->data.dec = val;
}