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r4 2022-08-22 23:43:21 -04:00
parent 6475d9c457
commit 824153a9df
5 changed files with 876 additions and 0 deletions
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16
Makefile Normal file
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READLINEFLAGS = -lreadline -DENABLE_READLINE
LDFLAGS =
CFLAGS = -Ofast -march=native -Wall -pedantic -Werror -lm $(READLINEFLAGS)
#CFLAGS = -ggdb -Wall -pedantic -Werror -lm $(READLINEFLAGS)
CC = cc
EXE = qc
all: $(EXE)
$(EXE): main.c expr.c expr.h expr_config.h
$(CC) -o $@ main.c expr.c $(LDFLAGS) $(CFLAGS)
.PHONY: clean
clean:
rm -f $(EXE)

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#include <math.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "expr.h"
#define EXPR_INCLUDE_CONFIG
#include "expr_config.h"
/* Builtin funcs array */
const size_t expr_n_builtin_funcs = sizeof(_builtin_funcs) / sizeof(_builtin_funcs[0]);
ExprBuiltinFunc *expr_builtin_funcs = _builtin_funcs;
/* Builtin vars array */
const size_t expr_n_builtin_vars = sizeof(_builtin_vars) / sizeof(_builtin_vars[0]);
ExprBuiltinVar *expr_builtin_vars = _builtin_vars;
#define TRY(x) {ExprError _err = x; if (_err.err != NULL) return _err;}
typedef struct {
size_t start, end;
enum {
TokNull,
TokOp,
TokNum,
TokIdent,
} kind;
union {
double Num;
char Char;
char *Str;
};
} Tok;
typedef struct Var {
char *name;
double val;
} Var;
typedef struct Func {
char *name;
double (*func)(double *args);
size_t n_args;
} Func;
struct _Expr {
Tok *toks_working;
size_t toks_working_len;
Tok *toks;
size_t toks_len;
size_t toks_cap;
Var *vars;
size_t vars_len;
size_t vars_cap;
Func *funcs;
size_t funcs_len;
size_t funcs_cap;
};
static size_t smap_get_idx(void *smap, const char *key, size_t type_size, size_t cap);
static void *smap_get_for_setting(void **smap, const char *key, size_t type_size, size_t *len, size_t *cap);
static void del_toks(Expr *e, Tok *start, Tok *end);
static ExprError collapse(Expr *e, Tok *t) __attribute__((warn_unused_result));
static ExprError eval(Expr *e, Tok *t, double *out_res) __attribute__((warn_unused_result));
static uint32_t fnv1a32(const void *data, size_t n);
static Func get_func(Expr *e, const char *name);
static void push_tok(Expr *e, Tok t);
static ExprError tokenize(Expr *e, const char *expr) __attribute__((warn_unused_result));
const static uint8_t op_prec[256] = {
['('] = 0, /* A precedence of 0 is reserved for delimiters. */
[')'] = 0,
[','] = 0,
['+'] = 1,
['-'] = 1,
['*'] = 2,
['/'] = 2,
['^'] = 3,
};
#define OP_PREC(tok_char) (op_prec[(size_t)tok_char])
const static enum {
OrderLtr,
OrderRtl,
} op_order[256] = {
['('] = OrderLtr,
[')'] = OrderLtr,
['+'] = OrderLtr,
['-'] = OrderLtr,
['*'] = OrderLtr,
['/'] = OrderLtr,
['^'] = OrderRtl,
};
#define OP_ORDER(tok_char) (op_order[(size_t)tok_char])
#define IS_NUM(c) (c >= '0' && c <= '9')
#define IS_ALPHA(c) ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'))
#define IS_SYMBOL(c) ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'))
Expr *expr_new() {
Expr *res = malloc(sizeof(Expr));
*res = (Expr){0};
for (size_t i = 0; i < expr_n_builtin_funcs; i++) {
expr_set_func(res, expr_builtin_funcs[i].name, expr_builtin_funcs[i].func, expr_builtin_funcs[i].n_args);
}
for (size_t i = 0; i < expr_n_builtin_vars; i++) {
expr_set_var(res, expr_builtin_vars[i].name, expr_builtin_vars[i].val);
}
return res;
}
void expr_destroy(Expr *e) {
for (size_t i = 0; i < e->toks_len; i++) {
if (e->toks[i].kind == TokIdent)
free(e->toks[i].Str);
}
free(e->toks);
free(e->toks_working);
for (size_t i = 0; i < e->vars_cap; i++)
free(e->vars[i].name);
free(e->vars);
for (size_t i = 0; i < e->funcs_cap; i++)
free(e->funcs[i].name);
free(e->funcs);
free(e);
}
ExprError expr_set(Expr *e, const char *expr) {
for (size_t i = 0; i < e->toks_len; i++) {
if (e->toks[i].kind == TokIdent)
free(e->toks[i].Str);
}
free(e->toks_working); e->toks_working = NULL;
e->toks_working_len = 0;
free(e->toks); e->toks = NULL;
e->toks_len = 0;
e->toks_cap = 0;
TRY(tokenize(e, expr));
return (ExprError){0};
}
ExprError expr_eval(Expr *e, double *out_res) {
e->toks_working = realloc(e->toks_working, sizeof(Tok) * e->toks_len);
memcpy(e->toks_working, e->toks, sizeof(Tok) * e->toks_len);
e->toks_working_len = e->toks_len;
TRY(eval(e, e->toks_working, out_res));
return (ExprError){0};
}
static size_t smap_get_idx(void *smap, const char *key, size_t type_size, size_t cap) {
size_t i = fnv1a32(key, strlen(key)) & (cap - 1);
while (1) {
void *i_ptr = (uint8_t*)smap + type_size * i;
char *i_key = *((char**)i_ptr);
if (i_key == NULL || strcmp(i_key, key) == 0) {
return i;
}
i = (i + 1) % cap;
}
}
static void *smap_get_for_setting(void **smap, const char *key, size_t type_size, size_t *len, size_t *cap) {
if (*cap == 0 || (double)*len / (double)*cap >= 0.7) {
size_t new_cap = *cap == 0 ? 16 : *cap * 2;
void *new = malloc(type_size * new_cap);
for (size_t i = 0; i < new_cap; i++)
*((char**)((uint8_t*)new + type_size * i)) = NULL;
for (size_t i = 0; i < *cap; i++) {
void *i_ptr = (uint8_t*)*smap + type_size * i;
char *i_key = *((char**)i_ptr);
if (i_key != NULL) {
void *ptr = (uint8_t*)new + type_size * smap_get_idx(new, i_key, type_size, new_cap);
memcpy(ptr, i_ptr, type_size);
}
}
free(*smap);
*cap = new_cap;
*smap = new;
}
void *ptr = (uint8_t*)*smap + type_size * smap_get_idx(*smap, key, type_size, *cap);
char **keyptr = (char**)ptr;
if (*keyptr == NULL) {
*keyptr = strdup(key);
(*len)++;
}
return ptr;
}
void expr_set_var(Expr *e, const char *name, double val) {
Var *v = smap_get_for_setting((void**)&e->vars, name, sizeof(Var), &e->vars_len, &e->vars_cap);
v->val = val;
}
bool expr_get_var(Expr *e, const char *name, double *out) {
Var v = e->vars[smap_get_idx(e->vars, name, sizeof(Var), e->vars_cap)];
*out = v.name == NULL ? NAN : v.val;
return v.name != NULL;
}
void expr_set_func(Expr *e, const char *name, double (*func)(double *args), size_t n_args) {
Func *v = smap_get_for_setting((void**)&e->funcs, name, sizeof(Func), &e->funcs_len, &e->funcs_cap);
v->func = func;
v->n_args = n_args;
}
static void del_toks(Expr *e, Tok *start, Tok *end) {
memmove(start, end, (e->toks_working_len - (end - e->toks_working)) * sizeof(Tok));
e->toks_working_len -= end - start;
}
static ExprError collapse(Expr *e, Tok *t) {
/* Collapse factor. */
if (t[1].kind == TokOp && t[1].Char == '-') {
TRY(collapse(e, t + 1));
if (t[2].kind != TokNum) {
return (ExprError){.start = t[2].start, .end = t[2].end, .err = "invalid expression after minus factor"};
}
t[2].Num *= -1.0;
del_toks(e, t + 1, t + 2);
}
/* Collapse parentheses. */
if (t[1].kind == TokOp && t[1].Char == '(') {
double res;
TRY(eval(e, t + 1, &res));
size_t i;
for (i = 2; !(t[i].kind == TokOp && OP_PREC(t[i].Char) == 0); i++);
del_toks(e, t + 2, t + i + 1);
/* Put the newly evaluated value into place. */
t[1].kind = TokNum;
t[1].Num = res;
}
if (t[1].kind == TokIdent) {
if (t + 2 < e->toks_working + e->toks_working_len && (t[2].kind == TokOp && t[2].Char == '(')) {
/* Collapse function. */
double arg_results[16];
size_t arg_results_size = 0;
t += 2;
while (1) {
if (arg_results_size < 16) {
double res;
TRY(eval(e, t, &res));
arg_results[arg_results_size++] = res;
}
size_t i = 1;
for (; !(t[i].kind == TokOp && OP_PREC(t[i].Char) == 0); i++);
bool end = t[i].Char == ')';
if (t[i].Char == ',')
del_toks(e, t, t + i);
else if (t[i].Char == ')')
del_toks(e, t, t + i + 1);
if (end)
break;
}
t -= 2;
Func func = get_func(e, t[1].Str);
if (func.name == NULL)
return (ExprError){.start = t[1].start, .end = t[1].end, .err = "unknown function"};
if (arg_results_size != func.n_args)
return (ExprError){.start = t[1].start, .end = t[1].end, .err = "invalid number of arguments to function"};
t[1].kind = TokNum;
t[1].Num = func.func(arg_results);
} else {
/* Collapse variable. */
t[1].kind = TokNum;
if (!expr_get_var(e, t[1].Str, &t[1].Num))
return (ExprError){.start = t[1].start, .end = t[1].end, .err = "unknown variable"};
}
}
return (ExprError){0};
}
static ExprError eval(Expr *e, Tok *t, double *out_res) {
if (!(t[0].kind == TokOp && OP_PREC(t[0].Char) == 0)) {
return (ExprError){.start = t[0].start, .end = t[0].end, .err = "expected delimiter at beginning of expression"};
}
while (1) {
TRY(collapse(e, t));
if (!(t[0].kind == TokOp && t[1].kind == TokNum && t[2].kind == TokOp)) {
return (ExprError){.start = t[0].start, .end = t[1].end, .err = "invalid token order"};
}
const char curr_op = t[0].Char;
const uint8_t curr_prec = OP_PREC(curr_op);
const char next_op = t[2].Char;
const uint8_t next_prec = OP_PREC(next_op);
/* Delimiters have a precedence of 0; if we have a number between two delimiters, we're done. */
if (curr_prec == 0 && next_prec == 0) {
*out_res = t[1].Num;
return (ExprError){0};
}
if (next_prec > curr_prec || (next_prec == curr_prec && OP_ORDER(curr_op) == OrderRtl)) {
t += 2;
} else if (next_prec < curr_prec || (next_prec == curr_prec && OP_ORDER(curr_op) == OrderLtr)) {
double res;
double lhs = t[-1].Num, rhs = t[1].Num;
switch (curr_op) {
case '+': res = lhs + rhs; break;
case '-': res = lhs - rhs; break;
case '*': res = lhs * rhs; break;
case '/': res = lhs / rhs; break;
case '^': res = pow(lhs, rhs); break;
default:
return (ExprError){.start = t[0].start, .end = t[0].end, .err = "invalid operator"};
}
t[1].Num = res;
del_toks(e, t - 1, t + 1);
t -= 2;
}
}
}
static uint32_t fnv1a32(const void *data, size_t n) {
uint32_t res = 2166136261u;
for (size_t i = 0; i < n; i++) {
res ^= ((uint8_t*)data)[i];
res *= 16777619u;
}
return res;
}
static Func get_func(Expr *e, const char *name) {
return e->funcs[smap_get_idx(e->funcs, name, sizeof(Func), e->funcs_cap)];
}
static void push_tok(Expr *e, Tok t) {
if (e->toks_len >= e->toks_cap) {
size_t new_cap = e->toks_cap == 0 ? 16 : e->toks_cap * 2;
e->toks = realloc(e->toks, sizeof(Tok) * new_cap);
e->toks_cap = new_cap;
}
e->toks[e->toks_len++] = t;
}
static ExprError tokenize(Expr *e, const char *expr) {
size_t start;
push_tok(e, (Tok){.start = 0, .end = 1, .kind = TokOp, .Char = '('});
/* We try to use the stack first for parenthesis tracking and only resort
* to heap allocation if the depth exceeds 16. */
size_t paren_depth = 0;
size_t parens_cap = 16;
size_t *h_parens = NULL;
size_t s_parens[16];
size_t *parens = s_parens;
Tok last;
const char *curr = expr;
for (char c = *curr; c != 0; c = *(++curr)) {
if (e->toks_len > 0)
last = e->toks[e->toks_len-1];
else
last = (Tok){.kind = TokNull};
if (c == ' ')
continue;
if (IS_NUM(c) || c == '.') {
bool dot_seen = c == '.';
bool e_seen = false;
char add_e_as_var = 0;
char buf[32];
start = curr - expr;
buf[0] = c;
size_t i = 1;
while (i < 31 && (IS_NUM(curr[i]) || curr[i] == '.' || curr[i] == 'e' || curr[i] == 'E' || ((curr[i-1] == 'e' || curr[i-1] == 'E') && (curr[i] == '-' || curr[i] == '+')))) {
if (curr[i] == '.') {
if (dot_seen) {
free(h_parens);
return (ExprError){.start = start + i, .end = start + i, .err = "more than one dot in decimal number"};
} else if (e_seen) {
return (ExprError){.start = start + i, .end = start + i, .err = "decimal dot not allowed in exponent"};
} else
dot_seen = true;
}
if (curr[i] == 'e' || curr[i] == 'E') {
if (e_seen) {
free(h_parens);
return (ExprError){.start = start + i, .end = start + i, .err = "more than one 'e' or 'E' in decimal number"};
} else
e_seen = true;
}
buf[i] = curr[i];
i++;
}
if (i > 0 && (curr[i-1] == 'e' || curr[i-1] == 'E'))
add_e_as_var = curr[i-1];
curr += i - 1;
if (add_e_as_var)
buf[--i] = 0;
else
buf[i] = 0;
char *endptr;
double num = strtod(buf, &endptr);
size_t endpos = endptr - buf;
if (endpos != i) {
free(h_parens);
return (ExprError){.start = start + endpos, .end = start + endpos, .err = "error parsing number"};
}
if (last.kind == TokIdent || (last.kind == TokOp && last.Char == ')') || last.kind == TokNum)
push_tok(e, (Tok){.start = last.end + 1, .end = last.end + 1, .kind = TokOp, .Char = '*'});
push_tok(e, (Tok){.start = start, .end = curr - expr, .kind = TokNum, .Num = num});
if (add_e_as_var) {
char b[2] = { add_e_as_var, 0 };
push_tok(e, (Tok){.start = curr - expr + 1, .end = curr - expr + 1, .kind = TokOp, .Char = '*'});
push_tok(e, (Tok){.start = curr - expr - 1, .end = curr - expr - 1, .kind = TokIdent, .Str = strdup(b)});
}
continue;
}
if (IS_SYMBOL(c)) {
start = curr - expr;
char *buf = malloc(32);
buf[0] = c;
size_t i = 1;
while (i < 31 && IS_SYMBOL(curr[i])) {
buf[i] = curr[i];
i++;
}
curr += i - 1;
buf[i++] = 0;
if (last.kind == TokIdent || (last.kind == TokOp && last.Char == ')') || last.kind == TokNum)
push_tok(e, (Tok){.start = last.end + 1, .end = last.end + 1, .kind = TokOp, .Char = '*'});
push_tok(e, (Tok){.start = start, .end = curr - expr, .kind = TokIdent, .Str = buf});
continue;
}
if (c == '(') {
if (paren_depth+1 > parens_cap) {
bool h_n = h_parens == NULL;
parens = h_parens = realloc(h_parens, sizeof(size_t) * (parens_cap *= 2));
if (h_n) {
memcpy(h_parens, s_parens, sizeof(size_t) * 16);
}
}
parens[paren_depth++] = curr - expr;
} else if (c == ')') {
if (paren_depth == 0) {
free(h_parens);
return (ExprError){.start = curr - expr, .end = curr - expr, .err = "unmatched ')'"};
}
paren_depth--;
}
switch (c) {
case '(':
case ')':
case ',':
case '+':
case '-':
case '*':
case '/':
case '^': {
if (c == '(' && ((last.kind == TokOp && last.Char == ')') || last.kind == TokNum))
push_tok(e, (Tok){.start = last.end + 1, .end = last.end + 1, .kind = TokOp, .Char = '*'});
push_tok(e, (Tok){.start = curr - expr, .end = curr - expr, .kind = TokOp, .Char = c});
break;
}
default:
free(h_parens);
return (ExprError){.start = curr - expr, .end = curr - expr, .err = "unrecognized symbol"};
}
}
if (paren_depth > 0) {
size_t p = parens[paren_depth-1];
free(h_parens);
return (ExprError){.start = p, .end = p, .err = "unmatched '('"};
}
push_tok(e, (Tok){.start = curr - expr, .end = curr - expr, .kind = TokOp, .Char = ')'});
free(h_parens);
return (ExprError){0};
}

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#ifndef __EXPR_H__
#define __EXPR_H__
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
typedef struct {
size_t start, end;
const char *err;
} ExprError;
typedef struct {
const char *name;
const char *description;
double (*func)(double *args);
const char **arg_names;
size_t n_args;
} ExprBuiltinFunc;
typedef struct {
const char *name;
const char *description;
double val;
} ExprBuiltinVar;
typedef struct _Expr Expr;
extern ExprBuiltinFunc *expr_builtin_funcs;
extern const size_t expr_n_builtin_funcs;
extern ExprBuiltinVar *expr_builtin_vars;
extern const size_t expr_n_builtin_vars;
Expr *expr_new();
void expr_destroy(Expr *e);
ExprError expr_set(Expr *e, const char *expr) __attribute__((warn_unused_result));
ExprError expr_eval(Expr *e, double *out_res) __attribute__((warn_unused_result));
void expr_set_var(Expr *e, const char *name, double val);
bool expr_get_var(Expr *e, const char *name, double *out); /* Returns false if not present */
void expr_set_func(Expr *e, const char *name, double (*func)(double *args), size_t n_args);
#endif /* __EXPR_H__ */

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#ifndef EXPR_INCLUDE_CONFIG
#error expr_config.h should not be imported by any files other than expr.c
#endif
static double fn_sqrt(double *args) {return sqrt(args[0]); }
static double fn_cbrt(double *args) {return cbrt(args[0]); }
static double fn_pow(double *args) {return pow(args[0], args[1]); }
static double fn_exp(double *args) {return exp(args[0]); }
static double fn_ln(double *args) {return log(args[0]); }
static double fn_log(double *args) {return log(args[1]) / log(args[0]);}
static double fn_mod(double *args) {return fmod(args[0], args[1]); }
static double fn_round(double *args) {return round(args[0]); }
static double fn_floor(double *args) {return floor(args[0]); }
static double fn_ceil(double *args) {return ceil(args[0]); }
static double fn_sin(double *args) {return sin(args[0]); }
static double fn_cos(double *args) {return cos(args[0]); }
static double fn_tan(double *args) {return tan(args[0]); }
static double fn_asin(double *args) {return asin(args[0]); }
static double fn_acos(double *args) {return acos(args[0]); }
static double fn_atan(double *args) {return atan(args[0]); }
static double fn_sinh(double *args) {return sinh(args[0]); }
static double fn_cosh(double *args) {return cosh(args[0]); }
static double fn_tanh(double *args) {return tanh(args[0]); }
static double fn_asinh(double *args) {return asinh(args[0]); }
static double fn_acosh(double *args) {return acosh(args[0]); }
static double fn_atanh(double *args) {return atanh(args[0]); }
static double fn_abs(double *args) {return fabs(args[0]); }
static double fn_hypot(double *args) {return hypot(args[0], args[1]); }
static double fn_polar(double *args) {return atan2(args[1], args[0]); }
static double fn_max(double *args) {return fmax(args[0], args[1]); }
static double fn_min(double *args) {return fmin(args[0], args[1]); }
static double fn_rad(double *args) {return args[0] / M_PI * 180.0; }
static double fn_deg(double *args) {return args[0] / 180.0 * M_PI; }
static const char *arg_names_x[] = {"x"};
static const char *arg_names_xy[] = {"x", "y"};
static const char *arg_names_nx[] = {"n", "x"};
static ExprBuiltinFunc _builtin_funcs[] = {
{"sqrt", "square root of x", fn_sqrt, arg_names_x, 1},
{"cbrt", "cube root of x", fn_cbrt, arg_names_x, 1},
{"pow", "x^y", fn_pow, arg_names_xy, 2},
{"exp", "e^x", fn_exp, arg_names_x, 1},
{"ln", "natural log (base e) of x", fn_ln, arg_names_x, 1},
{"log", "log (base n) of x", fn_log, arg_names_nx, 2},
{"mod", "x%y", fn_mod, arg_names_xy, 2},
{"round", "closest integer to x", fn_round, arg_names_x, 1},
{"floor", "greatest integer less than x", fn_floor, arg_names_x, 1},
{"ceil", "smallest integer grater than x", fn_ceil, arg_names_x, 1},
{"sin", "sine of x", fn_sin, arg_names_x, 1},
{"cos", "cosine of x", fn_cos, arg_names_x, 1},
{"tan", "tangent of x", fn_tan, arg_names_x, 1},
{"asin", "inverse sine of x", fn_asin, arg_names_x, 1},
{"acos", "inverse cosine of x", fn_acos, arg_names_x, 1},
{"atan", "inverse tangent of x", fn_atan, arg_names_x, 1},
{"sinh", "hyperbolic sine of x", fn_sinh, arg_names_x, 1},
{"cosh", "hyperbolic cosine of x", fn_cosh, arg_names_x, 1},
{"tanh", "hyperbolic tangent of x", fn_tanh, arg_names_x, 1},
{"asinh", "inverse hyperbolic sine of x", fn_asinh, arg_names_x, 1},
{"acosh", "inverse hyperbolic cosine of x", fn_acosh, arg_names_x, 1},
{"atanh", "inverse hyperbolic tangent of x", fn_atanh, arg_names_x, 1},
{"abs", "absolute value of x", fn_abs, arg_names_x, 1},
{"hypot", "sqrt(x^2+y^2)", fn_hypot, arg_names_xy, 2},
{"polar", "polar coordinates to radians", fn_polar, arg_names_xy, 2},
{"max", "the greater value of x and y", fn_max, arg_names_xy, 2},
{"min", "the smaller value of x and y", fn_min, arg_names_xy, 2},
{"rad", "x (radians) to degrees", fn_rad, arg_names_x, 1},
{"deg", "x (degrees) to radians", fn_deg, arg_names_x, 1},
};
static ExprBuiltinVar _builtin_vars[] = {
{"pi", "π", M_PI },
{"tau", "τ = 2π", 2.0 * M_PI },
{"e", "Euler's number", M_E },
{"phi", "golden ratio", 1.61803398874989484820},
{"h", "Planck constant (Js)", 6.62607015e-34 },
{"NA", "Avogadro constant (1/mol)", 6.02214076e23 },
{"c", "speed of light (m/s)", 299792458 },
{"g", "gravitational acceleration (m/s^2)", 9.80665 },
{"G", "gravitational constant (N(m/kg)^2)", 6.673889e-11 },
{"k", "Boltzmann constant (J/K)", 1.380649e-23 },
};
#undef EXPR_INCLUDE_CONFIG

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#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#ifdef ENABLE_READLINE
#include <stdlib.h>
#include <readline/readline.h>
#include <readline/history.h>
#endif
#include "expr.h"
#define ssub(_x, _y) ((_x) >= (_y) ? (_x) - (_y) : 0)
#define bufprint(_buf, _n, ...) _n += snprintf(_buf + _n, ssub(sizeof(buf), _n), __VA_ARGS__)
static Expr *e;
static bool running = true;
static bool last_status_ok = true;
#ifdef ENABLE_READLINE
static bool sigwinch_received = false;
static size_t completer_idx, completer_len;
static bool completer_funcs;
#endif
static void print_help() {
fprintf(stderr,
"Usage:\n"
" qc \"<expression>\" -- evaluate expression\n"
" qc -- run in REPL mode\n"
" qc --help -- show this page\n"
"Syntax:\n"
" Numbers: 123.45 or 1.2345e2 or 1.2345E2\n"
" Precedence | Operations\n"
" -----------+------------\n"
" 1 (LtR) | +, -\n"
" 2 (LtR) | *, /\n"
" 3 (RtL) | ^\n"
" Other symbols: (, ), - (prefix)\n");
char buf[32][128];
size_t maxw[2];
maxw[0] = 0;
fprintf(stderr, "Builtin functions:\n");
for (size_t i = 0; i < expr_n_builtin_funcs; i++) {
assert(i < 32);
size_t n = 0;
bufprint(buf[i], n, "%s(", expr_builtin_funcs[i].name);
for (size_t j = 0; j < expr_builtin_funcs[i].n_args; j++) {
if (j != 0)
bufprint(buf[i], n, ", ");
bufprint(buf[i], n, "%s", expr_builtin_funcs[i].arg_names[j]);
}
bufprint(buf[i], n, ")");
if (n > maxw[0])
maxw[0] = n;
}
for (size_t i = 0; i < expr_n_builtin_funcs; i++) {
fprintf(stderr, " %s%*s - %s\n", buf[i], (int)(maxw[0] - strlen(buf[i])), "", expr_builtin_funcs[i].description);
}
maxw[0] = maxw[1] = 0;
fprintf(stderr, "Builtin variables:\n");
for (size_t i = 0; i < expr_n_builtin_vars; i++) {
assert(i < 32);
size_t n = strlen(expr_builtin_vars[i].name);
if (n > maxw[0])
maxw[0] = n;
n = snprintf(buf[i], 128, "%.*g", 15, expr_builtin_vars[i].val);
if (n > maxw[1])
maxw[1] = n;
}
for (size_t i = 0; i < expr_n_builtin_vars; i++) {
fprintf(stderr, " %s%*s = %s%*s - %s\n", expr_builtin_vars[i].name, (int)(maxw[0] - strlen(expr_builtin_vars[i].name)), "", buf[i], (int)(maxw[1] - strlen(buf[i])), "", expr_builtin_vars[i].description);
}
}
static void sig_handler(int signum) {
running = false;
fprintf(stderr, "\nExiting\n");
}
static bool run(const char *line) {
if (line == NULL || line[0] == 0)
return line != NULL;
if (strcmp(line, "help") == 0) {
print_help();
return true;
}
double res;
ExprError err;
err = expr_set(e, line);
if (err.err == NULL)
err = expr_eval(e, &res);
if (err.err == NULL) {
printf("%.*g\n", 15, res);
} else {
fprintf(stderr, "Error parsing expression:\n");
fprintf(stderr, "%s\n", line);
fprintf(stderr, "%*s", (int)err.start, "");
for (size_t i = err.start; i <= err.end; i++)
fprintf(stderr, "^");
fprintf(stderr, "\n%s\n", err.err);
}
return err.err == NULL;
}
#if ENABLE_READLINE
static void winch_handler(int signum) {
sigwinch_received = true;
}
static void line_handler(char *line) {
if (line == NULL) {
rl_callback_handler_remove();
running = false;
} else {
add_history(line);
last_status_ok = run(line);
free(line);
}
}
static char *completer(const char *text, int state) {
if (!state) {
completer_idx = 0;
completer_len = strlen(text);
completer_funcs = false;
}
while (1) {
if (completer_funcs) {
if (completer_idx >= expr_n_builtin_funcs) {
break;
}
} else {
if (completer_idx >= expr_n_builtin_vars) {
completer_funcs = true;
completer_idx = 0;
}
}
const char *name;
if (completer_funcs)
name = expr_builtin_funcs[completer_idx].name;
else
name = expr_builtin_vars[completer_idx].name;
completer_idx++;
if (strncmp(name, text, completer_len) == 0) {
rl_completion_append_character = completer_funcs ? '(' : 0;
return strdup(name);
}
}
return NULL;
}
#endif
int main(int argc, const char **argv) {
#ifdef ENABLE_READLINE
rl_catch_signals = false;
rl_readline_name = "qc";
rl_completion_entry_function = completer;
rl_basic_word_break_characters = "+-*/^() ";
signal (SIGWINCH, winch_handler);
#else
char buf[2048];
#endif
struct sigaction action = {0};
action.sa_handler = sig_handler;
if (sigaction(SIGINT, &action, NULL) == -1) {
fprintf(stderr, "Error setting up signal handler: %s\n", strerror(errno));
return 1;
}
e = expr_new();
if (argc == 1) {
printf("Running in REPL (read-evaluate-print loop) mode. Type `help` for more information.\n");
printf("Hit Ctrl+C to exit.\n");
} else if (argc == 2 && strcmp(argv[1], "-h") != 0 && strcmp(argv[1], "--help") != 0) {
return !run(argv[1]);
} else {
print_help();
return 1;
}
#ifdef ENABLE_READLINE
rl_callback_handler_install("> ", line_handler);
fd_set fds;
#endif
while (running) {
#ifdef ENABLE_READLINE
FD_ZERO(&fds);
FD_SET(fileno(rl_instream), &fds);
int r = select(FD_SETSIZE, &fds, NULL, NULL, NULL);
if (r < 0 && errno != EINTR) {
rl_callback_handler_remove();
break;
}
if (sigwinch_received) {
rl_resize_terminal();
sigwinch_received = false;
}
if (r < 0)
continue;
if (FD_ISSET(fileno(rl_instream), &fds))
rl_callback_read_char();
#else
printf("> ");
const char *line = fgets(buf, 2048, stdin);
if (line == NULL)
break;
size_t len = strlen(buf);
if (len == 0)
continue;
buf[len-1] = 0;
last_status_ok = run(line);
#endif
}
expr_destroy(e);
return !last_status_ok;
}