evalexpr: introduce single op_kind enum

This will allow making the precendence climbing cleaner
This commit is contained in:
Bruno BELANYI 2020-10-30 19:20:24 +01:00
parent 32d17134cd
commit f7c8413e3c
5 changed files with 32 additions and 23 deletions

View File

@ -15,8 +15,12 @@ struct ast_node *make_num(int val)
return ret;
}
struct ast_node *make_unop(enum unop_kind op, struct ast_node *tree)
struct ast_node *make_unop(enum op_kind op, struct ast_node *tree)
{
// Defensive programming
if (op >= BINOP_PLUS)
return NULL;
struct ast_node *ret = malloc(sizeof(*ret));
if (ret == NULL)
@ -29,9 +33,13 @@ struct ast_node *make_unop(enum unop_kind op, struct ast_node *tree)
return ret;
}
struct ast_node *make_binop(enum binop_kind op, struct ast_node *lhs,
struct ast_node *make_binop(enum op_kind op, struct ast_node *lhs,
struct ast_node *rhs)
{
// Defensive programming
if (op < BINOP_PLUS)
return NULL;
struct ast_node *ret = malloc(sizeof(*ret));
if (ret == NULL)

View File

@ -4,15 +4,14 @@
// Forward declaration
struct ast_node;
enum unop_kind
enum op_kind
{
// Prefix operators
UNOP_IDENTITY,
UNOP_NEGATE,
// Postfix operators
UNOP_FACT,
};
enum binop_kind
{
// Infix operators
BINOP_PLUS,
BINOP_MINUS,
BINOP_TIMES,
@ -22,13 +21,13 @@ enum binop_kind
struct unop_node
{
enum unop_kind op;
enum op_kind op;
struct ast_node *tree;
};
struct binop_node
{
enum binop_kind op;
enum op_kind op;
struct ast_node *lhs;
struct ast_node *rhs;
};
@ -51,9 +50,9 @@ struct ast_node
struct ast_node *make_num(int val);
struct ast_node *make_unop(enum unop_kind op, struct ast_node *tree);
struct ast_node *make_unop(enum op_kind op, struct ast_node *tree);
struct ast_node *make_binop(enum binop_kind op, struct ast_node *lhs,
struct ast_node *make_binop(enum op_kind op, struct ast_node *lhs,
struct ast_node *rhs);
void destroy_ast(struct ast_node *ast);

View File

@ -30,8 +30,9 @@ static int eval_unop(const struct unop_node *un_op)
return -eval_ast(un_op->tree);
case UNOP_FACT:
return my_fact(eval_ast(un_op->tree));
default:
UNREACHABLE();
}
UNREACHABLE();
}
static int eval_binop(const struct binop_node *bin_op)
@ -49,9 +50,10 @@ static int eval_binop(const struct binop_node *bin_op)
return EVAL_OP(/, bin_op);
case BINOP_POW:
return my_pow(eval_ast(bin_op->lhs), eval_ast(bin_op->rhs));
default:
UNREACHABLE();
}
#undef EVAL_OP
UNREACHABLE();
}
int eval_ast(const struct ast_node *ast)

View File

@ -37,7 +37,7 @@ static void skip_whitespace(const char **input)
eat_char(input);
}
static enum binop_kind char_to_binop(char c)
static enum op_kind char_to_binop(char c)
{
for (size_t i = 0; i < ARR_SIZE(ops); ++i)
if (ops[i].fix == OP_INFIX && c == ops[i].op[0])
@ -46,7 +46,7 @@ static enum binop_kind char_to_binop(char c)
UNREACHABLE();
}
static enum unop_kind char_to_unop(char c)
static enum op_kind char_to_unop(char c)
{
for (size_t i = 0; i < ARR_SIZE(ops); ++i)
if (ops[i].fix != OP_INFIX && c == ops[i].op[0])
@ -164,7 +164,7 @@ static struct ast_node *climbing_parse_internal(const char **input, int prec)
eat_char(input);
if (is_binop(c))
{
enum binop_kind op = char_to_binop(c);
enum op_kind op = char_to_binop(c);
struct ast_node *rhs = climbing_parse_internal(input, right_prec(c));
if (!rhs)
{
@ -227,7 +227,7 @@ static struct ast_node *parse_operand(const char **input)
int val = 0;
if (is_prefix(*input[0]))
{
enum unop_kind op = char_to_unop(*input[0]);
enum op_kind op = char_to_unop(*input[0]);
// Remove the parenthesis
eat_char(input);

View File

@ -61,7 +61,7 @@ struct ast_node *recursive_parse(const char *input)
return ast;
}
static enum binop_kind char_to_binop(char c)
static enum op_kind char_to_binop(char c)
{
switch (c)
{
@ -94,7 +94,7 @@ static struct ast_node *parse_expression(const char **input)
if (*input[0] == '+' || *input[0] == '-')
{
const enum binop_kind op = char_to_binop(*input[0]);
const enum op_kind op = char_to_binop(*input[0]);
eat_char(input);
@ -130,7 +130,7 @@ static struct ast_node *parse_term(const char **input)
if (*input[0] == '*' || *input[0] == '/')
{
const enum binop_kind op = char_to_binop(*input[0]);
const enum op_kind op = char_to_binop(*input[0]);
eat_char(input);
@ -151,7 +151,7 @@ static struct ast_node *parse_term(const char **input)
return lhs;
}
static enum unop_kind char_to_unop(char c)
static enum op_kind char_to_unop(char c)
{
switch (c)
{
@ -170,7 +170,7 @@ static struct ast_node *parse_factor(const char **input)
skip_whitespace(input); // Whitespace is not significant
while (*input[0] == '+' || *input[0] == '-')
{
const enum unop_kind op = char_to_unop(*input[0]);
const enum op_kind op = char_to_unop(*input[0]);
eat_char(input);
@ -197,7 +197,7 @@ static struct ast_node *parse_power(const char **input)
if (*input[0] == '^')
{
const enum binop_kind op = char_to_binop(*input[0]);
const enum op_kind op = char_to_binop(*input[0]);
eat_char(input);