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arangodb/3rdParty/snowball/compiler/generator_rust.c

1268 lines
35 KiB
C

#include <stdlib.h> /* for exit */
#include <string.h> /* for strlen */
#include <stdio.h> /* for fprintf etc */
#include "header.h"
/* prototypes */
static void generate(struct generator * g, struct node * p);
static void w(struct generator * g, const char * s);
static void writef(struct generator * g, const char * s, struct node * p);
enum special_labels {
x_return = -1
};
static int new_label(struct generator * g) {
return g->next_label++;
}
static struct str * vars_newname(struct generator * g) {
struct str * output;
g->var_number ++;
output = str_new();
str_append_string(output, "v_");
str_append_int(output, g->var_number);
return output;
}
/* Write routines for items from the syntax tree */
static void write_varname(struct generator * g, struct name * p) {
switch (p->type) {
case t_external:
break;
default: {
int ch = "SbirxG"[p->type];
write_char(g, ch);
write_char(g, '_');
break;
}
}
str_append_b(g->outbuf, p->b);
}
static void write_varref(struct generator * g, struct name * p) {
write_string(g, "context.");
write_varname(g, p);
}
static void write_hexdigit(struct generator * g, int n) {
write_char(g, n < 10 ? n + '0' : n - 10 + 'A');
}
static void write_hex(struct generator * g, int ch) {
write_string(g, "\\u{");
{
int i;
for (i = 12; i >= 0; i -= 4) write_hexdigit(g, ch >> i & 0xf);
}
write_string(g, "}");
}
static void write_literal_string(struct generator * g, symbol * p) {
int i = 0;
write_string(g, "\"");
while (i < SIZE(p)) {
int ch;
i += get_utf8(p + i, &ch);
if (32 <= ch && ch < 127) {
if (ch == '\"' || ch == '\\') write_string(g, "\\");
write_char(g, ch);
} else {
write_hex(g, ch);
}
}
write_string(g, "\"");
}
static void write_margin(struct generator * g) {
int i;
for (i = 0; i < g->margin; i++) write_string(g, " ");
}
static void write_comment(struct generator * g, struct node * p) {
write_margin(g);
write_string(g, "// ");
write_string(g, name_of_token(p->type));
if (p->name != 0) {
write_string(g, " ");
str_append_b(g->outbuf, p->name->b);
}
write_string(g, ", line ");
write_int(g, p->line_number);
write_newline(g);
}
static void write_block_start(struct generator * g) {
w(g, "~+{~N");
}
static void write_block_end(struct generator * g) /* block end */ {
w(g, "~-~M}~N");
}
static void write_savecursor(struct generator * g, struct node * p,
struct str * savevar) {
g->B[0] = str_data(savevar);
g->S[1] = "";
if (p->mode != m_forward) g->S[1] = "env.limit - ";
writef(g, "~Mlet ~B0 = ~S1env.cursor;~N", p);
}
static void restore_string(struct node * p, struct str * out, struct str * savevar) {
str_clear(out);
str_append_string(out, "env.cursor = ");
if (p->mode != m_forward) str_append_string(out, "env.limit - ");
str_append(out, savevar);
str_append_string(out, ";");
}
static void write_restorecursor(struct generator * g, struct node * p,
struct str * savevar) {
struct str * temp = str_new();
write_margin(g);
restore_string(p, temp, savevar);
write_str(g, temp);
write_newline(g);
str_delete(temp);
}
static void write_inc_cursor(struct generator * g, struct node * p) {
write_margin(g);
write_string(g, p->mode == m_forward ? "env.next_char();" : "env.previous_char();");
write_newline(g);
}
static void wsetlab_begin(struct generator * g, int n) {
g->I[0] = n;
w(g, "~M'lab~I0: loop {~N~+");
}
static void wsetlab_end(struct generator * g, int n) {
g->I[0] = n;
w(g, "~Mbreak 'lab~I0;~N");
w(g, "~-~M}~N");
}
static void wgotol(struct generator * g, int n) {
g->I[0] = n;
w(g, "~Mbreak 'lab~I0;~N");
}
static void write_failure(struct generator * g) {
if (str_len(g->failure_str) != 0) {
write_margin(g);
write_str(g, g->failure_str);
write_newline(g);
}
switch (g->failure_label)
{
case x_return:
w(g, "~Mreturn false;~N");
g->unreachable = true;
break;
default:
g->I[0] = g->failure_label;
w(g, "~Mbreak 'lab~I0;~N");
g->unreachable = true;
}
}
static void write_failure_if(struct generator * g, char * s, struct node * p) {
writef(g, "~Mif ", p);
writef(g, s, p);
writef(g, " ", p);
write_block_start(g);
write_failure(g);
write_block_end(g);
g->unreachable = false;
}
/* if at limit fail */
static void write_check_limit(struct generator * g, struct node * p) {
if (p->mode == m_forward) {
write_failure_if(g, "env.cursor >= env.limit", p);
} else {
write_failure_if(g, "env.cursor <= env.limit_backward", p);
}
}
/* Formatted write. */
static void writef(struct generator * g, const char * input, struct node * p) {
int i = 0;
int l = strlen(input);
while (i < l) {
int ch = input[i++];
if (ch != '~') {
write_char(g, ch);
continue;
}
switch (input[i++]) {
default: write_char(g, input[i - 1]); continue;
case 'C': write_comment(g, p); continue;
case 'f': write_block_start(g);
write_failure(g);
g->unreachable = false;
write_block_end(g);
continue;
case 'M': write_margin(g); continue;
case 'N': write_newline(g); continue;
case '{': write_block_start(g); continue;
case '}': write_block_end(g); continue;
case 'S': write_string(g, g->S[input[i++] - '0']); continue;
case 'B': write_b(g, g->B[input[i++] - '0']); continue;
case 'I': write_int(g, g->I[input[i++] - '0']); continue;
case 'V': write_varref(g, g->V[input[i++] - '0']); continue;
case 'W': write_varname(g, g->V[input[i++] - '0']); continue;
case 'L': write_literal_string(g, g->L[input[i++] - '0']); continue;
case '+': g->margin++; continue;
case '-': g->margin--; continue;
case 'n': write_string(g, g->options->name); continue;
}
}
}
static void w(struct generator * g, const char * s) {
writef(g, s, 0);
}
static void generate_AE(struct generator * g, struct node * p) {
const char * s;
switch (p->type) {
case c_name:
write_varref(g, p->name); break;
case c_number:
write_int(g, p->number); break;
case c_maxint:
write_string(g, "usize::MAX"); break;
case c_minint:
write_string(g, "usize::MIN"); break;
case c_neg:
write_char(g, '-'); generate_AE(g, p->right); break;
case c_multiply:
s = " * "; goto label0;
case c_plus:
s = " + "; goto label0;
case c_minus:
s = " - "; goto label0;
case c_divide:
s = " / ";
label0:
write_char(g, '('); generate_AE(g, p->left);
write_string(g, s); generate_AE(g, p->right); write_char(g, ')'); break;
case c_cursor:
w(g, "env.cursor"); break;
case c_limit:
w(g, p->mode == m_forward ? "env.limit" : "env.limit_backward"); break;
case c_lenof:
g->V[0] = p->name;
w(g, "~V0.chars().count()");
break;
case c_sizeof:
g->V[0] = p->name;
w(g, "~V0.len()");
break;
case c_len:
w(g, "env.current.chars().count()");
break;
case c_size:
w(g, "env.current.len()");
break;
}
}
static void generate_bra(struct generator * g, struct node * p) {
write_comment(g, p);
p = p->left;
while (p) {
generate(g, p);
p = p->right;
}
}
static void generate_and(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
int keep_c = K_needed(g, p->left);
write_comment(g, p);
if (keep_c) write_savecursor(g, p, savevar);
p = p->left;
while (p) {
generate(g, p);
if (g->unreachable) break;
if (keep_c && p->right != 0) write_restorecursor(g, p, savevar);
p = p->right;
}
str_delete(savevar);
}
static void generate_or(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
int keep_c = K_needed(g, p->left);
int a0 = g->failure_label;
struct str * a1 = str_copy(g->failure_str);
int out_lab = new_label(g);
int end_unreachable = true;
write_comment(g, p);
wsetlab_begin(g, out_lab);
if (keep_c) write_savecursor(g, p, savevar);
p = p->left;
str_clear(g->failure_str);
if (p == 0) {
/* p should never be 0 after an or: there should be at least two
* sub nodes. */
fprintf(stderr, "Error: \"or\" node without children nodes.");
exit (1);
}
while (p->right != 0) {
g->failure_label = new_label(g);
int label = g->failure_label;
wsetlab_begin(g, label);
generate(g, p);
if (!g->unreachable) {
wgotol(g, out_lab);
end_unreachable = false;
}
w(g, "~-~M}~N");
g->unreachable = false;
if (keep_c) write_restorecursor(g, p, savevar);
p = p->right;
}
g->failure_label = a0;
str_delete(g->failure_str);
g->failure_str = a1;
generate(g, p);
wsetlab_end(g, out_lab);
g->unreachable = end_unreachable;
str_delete(savevar);
}
static void generate_backwards(struct generator * g, struct node * p) {
write_comment(g, p);
writef(g,"~Menv.limit_backward = env.cursor;~N"
"~Menv.cursor = env.limit;~N", p);
generate(g, p->left);
w(g, "~Menv.cursor = env.limit_backward;~N");
}
static void generate_not(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
int keep_c = K_needed(g, p->left);
int a0 = g->failure_label;
struct str * a1 = str_copy(g->failure_str);
write_comment(g, p);
if (keep_c) {
write_savecursor(g, p, savevar);
}
g->failure_label = new_label(g);
int label = g->failure_label;
str_clear(g->failure_str);
wsetlab_begin(g, label);
generate(g, p->left);
g->failure_label = a0;
str_delete(g->failure_str);
g->failure_str = a1;
if (!g->unreachable) write_failure(g);
w(g, "~-~M}~N");
g->unreachable = false;
if (keep_c) write_restorecursor(g, p, savevar);
str_delete(savevar);
}
static void generate_try(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
int keep_c = K_needed(g, p->left);
write_comment(g, p);
if (keep_c) write_savecursor(g, p, savevar);
g->failure_label = new_label(g);
int label = g->failure_label;
if (keep_c) restore_string(p, g->failure_str, savevar);
wsetlab_begin(g, label);
generate(g, p->left);
wsetlab_end(g, label);
g->unreachable = false;
str_delete(savevar);
}
static void generate_set(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
writef(g, "~M~V0 = true;~N", p);
}
static void generate_unset(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
writef(g, "~M~V0 = false;~N", p);
}
static void generate_fail(struct generator * g, struct node * p) {
write_comment(g, p);
generate(g, p->left);
if (!g->unreachable) write_failure(g);
}
/* generate_test() also implements 'reverse' */
static void generate_test(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
int keep_c = K_needed(g, p->left);
write_comment(g, p);
if (keep_c) {
write_savecursor(g, p, savevar);
}
generate(g, p->left);
if (!g->unreachable) {
if (keep_c) {
write_restorecursor(g, p, savevar);
}
}
str_delete(savevar);
}
static void generate_do(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
int keep_c = K_needed(g, p->left);
write_comment(g, p);
if (keep_c) write_savecursor(g, p, savevar);
g->failure_label = new_label(g);
int label = g->failure_label;
str_clear(g->failure_str);
wsetlab_begin(g, label);
generate(g, p->left);
wsetlab_end(g, label);
g->unreachable = false;
if (keep_c) write_restorecursor(g, p, savevar);
str_delete(savevar);
}
static void generate_GO(struct generator * g, struct node * p, int style) {
int end_unreachable = false;
struct str * savevar = vars_newname(g);
int keep_c = style == 1 || repeat_restore(g, p->left);
int a0 = g->failure_label;
struct str * a1 = str_copy(g->failure_str);
int golab = new_label(g);
g->I[0] = golab;
write_comment(g, p);
w(g, "~M'golab~I0: loop {~N~+");
if (keep_c) write_savecursor(g, p, savevar);
g->failure_label = new_label(g);
wsetlab_begin(g, g->failure_label);
generate(g, p->left);
if (g->unreachable) {
/* Cannot break out of this loop: therefore the code after the
* end of the loop is unreachable.*/
end_unreachable = true;
} else {
/* include for goto; omit for gopast */
if (style == 1) write_restorecursor(g, p, savevar);
g->I[0] = golab;
w(g, "~Mbreak 'golab~I0;~N");
}
g->unreachable = false;
w(g, "~-~M}~N");
if (keep_c) write_restorecursor(g, p, savevar);
g->failure_label = a0;
str_delete(g->failure_str);
g->failure_str = a1;
write_check_limit(g, p);
write_inc_cursor(g, p);
write_block_end(g);
str_delete(savevar);
g->unreachable = end_unreachable;
}
static void generate_loop(struct generator * g, struct node * p) {
struct str * loopvar = vars_newname(g);
write_comment(g, p);
w(g, "~Mfor _ in 0..");
generate_AE(g, p->AE);
writef(g, " {~+~N", p);
generate(g, p->left);
w(g, "~-~M}~N");
str_delete(loopvar);
g->unreachable = false;
}
static void generate_repeat(struct generator * g, struct node * p, struct str * loopvar) {
struct str * savevar = vars_newname(g);
int keep_c = repeat_restore(g, p->left);
int replab = new_label(g);
g->I[0] = replab;
write_comment(g, p);
writef(g, "~M'replab~I0: loop{~N~+", p);
if (keep_c) write_savecursor(g, p, savevar);
g->failure_label = new_label(g);
str_clear(g->failure_str);
g->I[0] = g->failure_label;
w(g, "~M'lab~I0: for _ in 0..1 {~N~+");
generate(g, p->left);
if (!g->unreachable) {
if (loopvar != 0) {
g->B[0] = str_data(loopvar);
w(g, "~M~B0 -= 1;~N");
}
g->I[0] = replab;
w(g, "~Mcontinue 'replab~I0;~N");
}
w(g, "~-~M}~N");
g->unreachable = false;
if (keep_c) write_restorecursor(g, p, savevar);
g->I[0] = replab;
w(g, "~Mbreak 'replab~I0;~N~-~M}~N");
str_delete(savevar);
}
static void generate_atleast(struct generator * g, struct node * p) {
struct str * loopvar = vars_newname(g);
write_comment(g, p);
g->B[0] = str_data(loopvar);
w(g, "~Mlet mut ~B0 = ");
generate_AE(g, p->AE);
w(g, ";~N");
{
int a0 = g->failure_label;
struct str * a1 = str_copy(g->failure_str);
generate_repeat(g, p, loopvar);
g->failure_label = a0;
str_delete(g->failure_str);
g->failure_str = a1;
}
g->B[0] = str_data(loopvar);
write_failure_if(g, "~B0 > 0", p);
str_delete(loopvar);
}
static void generate_setmark(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
writef(g, "~M~V0 = env.cursor;~N", p);
}
static void generate_tomark(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? ">" : "<";
w(g, "~Mif env.cursor ~S0 "); generate_AE(g, p->AE);
writef(g, " ", p);
write_block_start(g);
write_failure(g);
write_block_end(g);
g->unreachable = false;
w(g, "~Menv.cursor = "); generate_AE(g, p->AE); writef(g, ";~N", p);
}
static void generate_atmark(struct generator * g, struct node * p) {
write_comment(g, p);
w(g, "~Mif env.cursor != "); generate_AE(g, p->AE);
writef(g, " ", p);
write_block_start(g);
write_failure(g);
write_block_end(g);
g->unreachable = false;
}
static void generate_hop(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "" : "-";
w(g, "~Mlet c = env.byte_index_for_hop(~S0");
generate_AE(g, p->AE);
w(g, ");~N");
g->S[0] = p->mode == m_forward ? "0" : "env.limit_backward";
write_failure_if(g, "~S0 as i32 > c || c > env.limit as i32", p);
writef(g, "~Menv.cursor = c as usize;~N", p);
}
static void generate_delete(struct generator * g, struct node * p) {
write_comment(g, p);
writef(g, "~Mif !env.slice_del() {~N"
"~+~Mreturn false;~N~-"
"~M}~N", p);
}
static void generate_next(struct generator * g, struct node * p) {
write_comment(g, p);
write_check_limit(g, p);
write_inc_cursor(g, p);
}
static void generate_tolimit(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "env.limit" : "env.limit_backward";
writef(g, "~Menv.cursor = ~S0;~N", p);
}
static void generate_atlimit(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "env.limit" : "env.limit_backward";
g->S[1] = p->mode == m_forward ? "<" : ">";
write_failure_if(g, "env.cursor ~S1 ~S0", p);
}
static void generate_leftslice(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "env.bra" : "env.ket";
writef(g, "~M~S0 = env.cursor;~N", p);
}
static void generate_rightslice(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "env.ket" : "env.bra";
writef(g, "~M~S0 = env.cursor;~N", p);
}
static void generate_assignto(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
writef(g, "~M~V0 = env.assign_to(~V0)~N", p);
}
static void generate_sliceto(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
writef(g, "~M~V0 = env.slice_to();~N"
"~Mif ~V0.is_empty() {~N"
"~+~Mreturn false;~N~-~M}~N", p);
}
static void generate_address(struct generator * g, struct node * p) {
symbol * b = p->literalstring;
if (b != 0) {
write_literal_string(g, b);
} else {
write_varref(g, p->name);
}
}
static void generate_insert(struct generator * g, struct node * p, int style) {
int keep_c = style == c_attach;
write_comment(g, p);
if (p->mode == m_backward) keep_c = !keep_c;
if (keep_c) w(g, "~Mlet c = env.cursor;~N");
w(g, "~Mlet (bra, ket) = (env.cursor, env.cursor);~N");
writef(g, "~Menv.insert(bra, ket, ", p);
generate_address(g, p);
writef(g, ");~N", p);
if (keep_c) w(g, "~Menv.cursor = c;~N");
}
static void generate_assignfrom(struct generator * g, struct node * p) {
int keep_c = p->mode == m_forward; /* like 'attach' */
write_comment(g, p);
if (keep_c) writef(g, "~Mlet c = env.cursor;~N", p);
/* Copying limits and cursors is necessary here because the rust
* borrowchecker does not like taking something from someone you are about
* to mutate... */
if (p->mode == m_forward) {
writef(g, "~Mlet (bra, ket) = (env.cursor, env.limit);~N", p);
} else {
writef(g, "~Mlet (bra, ket) = (env.limit_backward, env.cursor);~N", p);
}
/* If we deal with a string variable which is of type String we need to
* pass it by reference not by value. Literalstrings on the other hand are
* of type &'static str so we can pass them by value.
*/
if (p->literalstring) {
writef(g, "~Menv.insert(bra, ket, ", p);
} else {
writef(g, "~Menv.insert(bra, ket, &", p);
}
generate_address(g, p);
writef(g, ");~N", p);
if (keep_c) w(g, "~Menv.cursor = c;~N");
}
static void generate_slicefrom(struct generator * g, struct node * p) {
write_comment(g, p);
/* If we deal with a string variable which is of type String we need to
* pass it by reference not by value. Literalstrings on the other hand are
* of type &'static str so we can pass them by value.
*/
if (p->literalstring) {
w(g, "~Mif !env.slice_from(");
} else {
w(g, "~Mif !env.slice_from(&");
}
generate_address(g, p);
writef(g, ") {~N"
"~+~Mreturn false;~N~-~M}~N", p);
}
static void generate_setlimit(struct generator * g, struct node * p) {
struct str * savevar = vars_newname(g);
struct str * varname = vars_newname(g);
write_comment(g, p);
write_savecursor(g, p, savevar);
generate(g, p->left);
if (!g->unreachable) {
g->B[0] = str_data(varname);
if (p->mode == m_forward) {
w(g, "~Mlet ~B0 = env.limit - env.cursor;~N");
w(g, "~Menv.limit = env.cursor;~N");
} else {
w(g, "~Mlet ~B0 = env.limit_backward;~N");
w(g, "~Menv.limit_backward = env.cursor;~N");
}
write_restorecursor(g, p, savevar);
if (p->mode == m_forward) {
str_assign(g->failure_str, "env.limit += ");
str_append(g->failure_str, varname);
str_append_string(g->failure_str, ";");
} else {
str_assign(g->failure_str, "env.limit_backward = ");
str_append(g->failure_str, varname);
str_append_string(g->failure_str, ";");
}
generate(g, p->aux);
if (!g->unreachable) {
write_margin(g);
write_str(g, g->failure_str);
write_newline(g);
}
}
str_delete(varname);
str_delete(savevar);
}
/* dollar sets snowball up to operate on a string variable as if it were the
* current string */
static void generate_dollar(struct generator * g, struct node * p) {
struct str * savevar_env = vars_newname(g);
write_comment(g, p);
g->V[0] = p->name;
g->B[0] = str_data(savevar_env);
writef(g, "~Mlet ~B0 = env.clone();~N"
"~Menv.set_current_s(~V0.clone());~N"
"~Menv.cursor = 0;~N"
"~Menv.limit = env.current.len();~N", p);
generate(g, p->left);
if (!g->unreachable) {
g->V[0] = p->name;
/* Update string variable. */
w(g, "~M~V0 = env.current.clone().into_owned();~N");
/* Reset env */
w(g, "~M*env = ~B0;~N");
}
str_delete(savevar_env);
}
static void generate_integer_assign(struct generator * g, struct node * p, char * s) {
g->V[0] = p->name;
g->S[0] = s;
w(g, "~M~V0 ~S0 "); generate_AE(g, p->AE); w(g, ";~N");
}
static void generate_integer_test(struct generator * g, struct node * p, char * s) {
g->V[0] = p->name;
g->S[0] = s;
w(g, "~Mif !(~V0 ~S0 ");
generate_AE(g, p->AE);
w(g, ")");
write_block_start(g);
write_failure(g);
write_block_end(g);
g->unreachable = false;
}
static void generate_call(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
write_failure_if(g, "!~W0(env, context)", p);
}
static void generate_grouping(struct generator * g, struct node * p, int complement) {
struct grouping * q = p->name->grouping;
g->S[0] = p->mode == m_forward ? "" : "_b";
g->S[1] = complement ? "out" : "in";
g->V[0] = p->name;
g->I[0] = q->smallest_ch;
g->I[1] = q->largest_ch;
write_failure_if(g, "!env.~S1_grouping~S0(~W0, ~I0, ~I1)", p);
}
static void generate_namedstring(struct generator * g, struct node * p) {
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "" : "_b";
g->V[0] = p->name;
write_failure_if(g, "!env.eq_s~S0(&~V0)", p);
}
static void generate_literalstring(struct generator * g, struct node * p) {
symbol * b = p->literalstring;
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "" : "_b";
g->L[0] = b;
write_failure_if(g, "!env.eq_s~S0(&~L0)", p);
}
static void generate_setup_context(struct generator * g) {
struct name * q;
w(g, "~Mlet mut context = &mut Context {~+~N");
for (q = g->analyser->names; q; q = q->next) {
g->V[0] = q;
switch (q->type) {
case t_string:
w(g, "~M~W0: String::new(),~N");
break;
case t_integer:
w(g, "~M~W0: 0,~N");
break;
case t_boolean:
w(g, "~M~W0: false,~N");
break;
}
}
w(g, "~-~M};~N");
}
static void generate_define(struct generator * g, struct node * p) {
struct name * q = p->name;
struct str * saved_output = g->outbuf;
g->V[0] = q;
if (q->type == t_routine) {
w(g, "~N~Mfn ~W0(env: &mut SnowballEnv, context: &mut Context) -> bool {~+~N");
} else {
w(g, "~N~Mpub fn ~W0(env: &mut SnowballEnv) -> bool {~+~N");
generate_setup_context(g);
}
if (p->amongvar_needed) w(g, "~Mlet mut among_var;~N");
g->outbuf = str_new();
g->next_label = 0;
g->var_number = 0;
str_clear(g->failure_str);
g->failure_label = x_return;
g->unreachable = false;
generate(g, p->left);
if (!g->unreachable) w(g, "~Mreturn true;~N");
w(g, "~-~M}~N");
str_append(saved_output, g->outbuf);
str_delete(g->outbuf);
g->outbuf = saved_output;
}
static void generate_substring(struct generator * g, struct node * p) {
struct among * x = p->among;
write_comment(g, p);
g->S[0] = p->mode == m_forward ? "" : "_b";
g->I[0] = x->number;
if (x->command_count == 0 && x->starter == 0) {
write_failure_if(g, "env.find_among~S0(~A_~I0, context) == 0", p);
} else {
writef(g, "~Mamong_var = env.find_among~S0(~A_~I0, context);~N", p);
write_failure_if(g, "among_var == 0", p);
}
}
static void generate_among(struct generator * g, struct node * p) {
struct among * x = p->among;
int case_number = 1;
if (x->substring == 0) generate_substring(g, p);
if (x->command_count == 0 && x->starter == 0) return;
if (x->starter != 0) generate(g, x->starter);
p = p->left;
if (p != 0 && p->type != c_literalstring) p = p->right;
w(g, "~Mif among_var == 0 {~N~+");
write_failure(g);
g->unreachable = false;
w(g, "~-~M}");
while (p) {
if (p->type == c_bra && p->left != 0) {
g->I[0] = case_number++;
w(g, " else if among_var == ~I0 {~N~+");
generate(g, p);
w(g, "~-~M}");
g->unreachable = false;
}
p = p->right;
}
w(g, "~N");
}
static void generate_booltest(struct generator * g, struct node * p) {
write_comment(g, p);
g->V[0] = p->name;
write_failure_if(g, "!~V0", p);
}
static void generate_false(struct generator * g, struct node * p) {
write_comment(g, p);
write_failure(g);
}
static void generate_debug(struct generator * g, struct node * p) {
write_comment(g, p);
g->I[0] = g->debug_count++;
g->I[1] = p->line_number;
writef(g, "~Menv.debug(~I0, ~I1);~N", p);
}
static void generate(struct generator * g, struct node * p) {
int a0;
struct str * a1;
if (g->unreachable) return;
a0 = g->failure_label;
a1 = str_copy(g->failure_str);
switch (p->type)
{
case c_define: generate_define(g, p); break;
case c_bra: generate_bra(g, p); break;
case c_and: generate_and(g, p); break;
case c_or: generate_or(g, p); break;
case c_backwards: generate_backwards(g, p); break;
case c_not: generate_not(g, p); break;
case c_set: generate_set(g, p); break;
case c_unset: generate_unset(g, p); break;
case c_try: generate_try(g, p); break;
case c_fail: generate_fail(g, p); break;
case c_reverse:
case c_test: generate_test(g, p); break;
case c_do: generate_do(g, p); break;
case c_goto: generate_GO(g, p, 1); break;
case c_gopast: generate_GO(g, p, 0); break;
case c_repeat: generate_repeat(g, p, 0); break;
case c_loop: generate_loop(g, p); break;
case c_atleast: generate_atleast(g, p); break;
case c_setmark: generate_setmark(g, p); break;
case c_tomark: generate_tomark(g, p); break;
case c_atmark: generate_atmark(g, p); break;
case c_hop: generate_hop(g, p); break;
case c_delete: generate_delete(g, p); break;
case c_next: generate_next(g, p); break;
case c_tolimit: generate_tolimit(g, p); break;
case c_atlimit: generate_atlimit(g, p); break;
case c_leftslice: generate_leftslice(g, p); break;
case c_rightslice: generate_rightslice(g, p); break;
case c_assignto: generate_assignto(g, p); break;
case c_sliceto: generate_sliceto(g, p); break;
case c_assign: generate_assignfrom(g, p); break;
case c_insert:
case c_attach: generate_insert(g, p, p->type); break;
case c_slicefrom: generate_slicefrom(g, p); break;
case c_setlimit: generate_setlimit(g, p); break;
case c_dollar: generate_dollar(g, p); break;
case c_mathassign: generate_integer_assign(g, p, "="); break;
case c_plusassign: generate_integer_assign(g, p, "+="); break;
case c_minusassign: generate_integer_assign(g, p, "-="); break;
case c_multiplyassign:generate_integer_assign(g, p, "*="); break;
case c_divideassign: generate_integer_assign(g, p, "/="); break;
case c_eq: generate_integer_test(g, p, "=="); break;
case c_ne: generate_integer_test(g, p, "!="); break;
case c_gr: generate_integer_test(g, p, ">"); break;
case c_ge: generate_integer_test(g, p, ">="); break;
case c_ls: generate_integer_test(g, p, "<"); break;
case c_le: generate_integer_test(g, p, "<="); break;
case c_call: generate_call(g, p); break;
case c_grouping: generate_grouping(g, p, false); break;
case c_non: generate_grouping(g, p, true); break;
case c_name: generate_namedstring(g, p); break;
case c_literalstring: generate_literalstring(g, p); break;
case c_among: generate_among(g, p); break;
case c_substring: generate_substring(g, p); break;
case c_booltest: generate_booltest(g, p); break;
case c_false: generate_false(g, p); break;
case c_true: break;
case c_debug: generate_debug(g, p); break;
default: fprintf(stderr, "%d encountered\n", p->type);
exit(1);
}
g->failure_label = a0;
str_delete(g->failure_str);
g->failure_str = a1;
}
static void generate_start_comment(struct generator * g) {
w(g, "//! This file was generated automatically by the Snowball to Rust compiler~N");
w(g, "//! http://snowballstem.org/~N~N");
}
/* rustc emits warnings if variables don't match the style guide */
/* (i.e. upper-case for globals, snake case for fields etc.) */
/* To allow warning free compilation of generated code and */
/* consistency with snowball variable namings we allow some kind of warnings here */
static void generate_allow_warnings(struct generator * g) {
w(g, "#![allow(non_upper_case_globals)]~N");
w(g, "#![allow(non_snake_case)]~N");
w(g, "#![allow(unused_variables)]~N");
w(g, "#![allow(unused_mut)]~N");
}
static void generate_class_begin(struct generator * g) {
w(g, "use snowball::SnowballEnv;~N");
w(g, "use snowball::Among;~N~N");
}
static void generate_among_table(struct generator * g, struct among * x) {
struct amongvec * v = x->b;
g->I[0] = x->number;
g->I[1] = x->literalstring_count;
w(g, "~Mstatic A_~I0: &'static [Among<Context>; ~I1] = &[~N~+");
{
int i;
for (i = 0; i < x->literalstring_count; i++)
{
g->I[0] = v->i;
g->I[1] = v->result;
g->L[0] = v->b;
g->S[0] = ",";
w(g, "~MAmong(~L0, ~I0, ~I1, ");
if (v->function != 0)
{
w(g, "Some(&");
write_varname(g, v->function);
w(g, ")");
} else {
w(g, "None");
}
w(g, ")~S0~N");
v++;
}
}
w(g, "~-~M];~N~N");
}
static void generate_amongs(struct generator * g) {
struct among * x;
for (x = g->analyser->amongs; x; x = x->next) {
generate_among_table(g, x);
}
}
static void set_bit(symbol * b, int i) { b[i/8] |= 1 << i%8; }
static void generate_grouping_table(struct generator * g, struct grouping * q) {
int range = q->largest_ch - q->smallest_ch + 1;
int size = (range + 7)/ 8; /* assume 8 bits per symbol */
symbol * b = q->b;
symbol * map = create_b(size);
int i;
for (i = 0; i < size; i++) map[i] = 0;
for (i = 0; i < SIZE(b); i++) set_bit(map, b[i] - q->smallest_ch);
g->V[0] = q->name;
g->I[0] = size;
w(g, "~Mstatic ~W0: &'static [u8; ~I0] = &[");
for (i = 0; i < size; i++) {
write_int(g, map[i]);
if (i < size - 1) w(g, ", ");
}
w(g, "];~N~N");
lose_b(map);
}
static void generate_groupings(struct generator * g) {
struct grouping * q;
for (q = g->analyser->groupings; q; q = q->next) {
generate_grouping_table(g, q);
}
}
static void generate_members(struct generator * g) {
struct name * q;
w(g, "#[derive(Clone)]~N");
w(g, "struct Context {~+~N");
for (q = g->analyser->names; q; q = q->next) {
g->V[0] = q;
switch (q->type) {
case t_string:
w(g, "~M~W0: String,~N");
break;
case t_integer:
w(g, "~M~W0: usize,~N");
break;
case t_boolean:
w(g, "~M~W0: bool,~N");
break;
}
}
w(g, "~-}~N");
}
static void generate_methods(struct generator * g) {
struct node * p = g->analyser->program;
while (p != 0) {
generate(g, p);
g->unreachable = false;
p = p->right;
}
}
extern void generate_program_rust(struct generator * g) {
g->outbuf = str_new();
g->failure_str = str_new();
generate_start_comment(g);
generate_allow_warnings(g);
if (g->analyser->int_limits_used) {
/* std::usize is used in the code generated for usize::MAX and usize::MIN */
w(g, "use std::usize;~N~N");
}
generate_class_begin(g);
generate_amongs(g);
generate_groupings(g);
generate_members(g);
generate_methods(g);
output_str(g->options->output_src, g->outbuf);
str_delete(g->failure_str);
str_delete(g->outbuf);
}