parsers for the grammars in the tieknots paper
This commit is contained in:
Mikael Vejdemo-Johansson
parent
6b8a3f262f
commit
7fdc687bd4
1 changed files with 331 additions and 0 deletions
331
examples/ties.c
Normal file
331
examples/ties.c
Normal file
|
|
@ -0,0 +1,331 @@
|
|||
//
|
||||
// Created by Mikael Vejdemo Johansson on 4/7/15.
|
||||
//
|
||||
// Intention: read in a parser, generate the system of equations for its
|
||||
// generating functions
|
||||
//
|
||||
|
||||
#include <inttypes.h>
|
||||
#include "../src/backends/contextfree.h"
|
||||
#include "../src/backends/lr.h"
|
||||
#include <stdio.h>
|
||||
|
||||
static const char *nonterminal_name(const HCFGrammar *g, const HCFChoice *nt)
|
||||
{
|
||||
static char buf[16] = {0}; // 14 characters in base 26 are enough for 64 bits
|
||||
|
||||
// find nt's number in g
|
||||
size_t n = (uintptr_t)h_hashtable_get(g->nts, nt);
|
||||
|
||||
// NB the start symbol (number 0) is always "A".
|
||||
int i;
|
||||
for(i=14; i>=0 && (n>0 || i==14); i--) {
|
||||
buf[i] = 'A' + n%26;
|
||||
n = n/26; // shift one digit
|
||||
}
|
||||
|
||||
return buf+i+1;
|
||||
}
|
||||
|
||||
|
||||
|
||||
void readsequence(FILE *file, uint32_t *count, uint32_t *length,
|
||||
const HCFGrammar *g, const HCFSequence *seq) {
|
||||
// tally up numbers of choices, and lengths of emitted strings.
|
||||
// Immediately emit any nonterminals encountered.
|
||||
HCFChoice** x = seq->items;
|
||||
|
||||
if (*x == NULL) {
|
||||
return;
|
||||
} else {
|
||||
fprintf(file, "1");
|
||||
HCharset cs;
|
||||
unsigned int i, cscount=0;
|
||||
for(; *x; x++) {
|
||||
switch((*x)->type) {
|
||||
case HCF_CHAR:
|
||||
(*length)++;
|
||||
break;
|
||||
case HCF_END:
|
||||
break;
|
||||
case HCF_CHARSET:
|
||||
cs = (*x)->charset;
|
||||
for(i=0; i<256; i++) {
|
||||
if (charset_isset(cs, i)) {
|
||||
cscount++;
|
||||
}
|
||||
}
|
||||
*count *= cscount;
|
||||
break;
|
||||
default: // HCF_CHOICE, non-terminal symbol
|
||||
fprintf(file, "*%s(t)", nonterminal_name(g, *x));
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// For each nt in g->nts
|
||||
// For each choice in nt->key->seq
|
||||
// For all elements in sequence
|
||||
// Accumulate counts
|
||||
// Accumulate string lengths
|
||||
// Emit count*t^length
|
||||
void h_pprint_gfeqns(FILE *file, const HCFGrammar *g) {
|
||||
if (g->nts->used < 1) {
|
||||
return;
|
||||
}
|
||||
|
||||
// determine maximum string length of symbol names
|
||||
int len;
|
||||
size_t s;
|
||||
for(len=1, s=26; s < g->nts->used; len++, s*=26);
|
||||
|
||||
// iterate over g->nts
|
||||
size_t i;
|
||||
HHashTableEntry *hte;
|
||||
for(i=0; i < g->nts->capacity; i++) {
|
||||
for(hte = &g->nts->contents[i]; hte; hte = hte->next) {
|
||||
if (hte->key == NULL) {
|
||||
continue;
|
||||
}
|
||||
|
||||
const HCFChoice *nt = hte->key;
|
||||
fprintf(file, "%s(t) = ", nonterminal_name(g, nt));
|
||||
|
||||
|
||||
for(HCFSequence **seq = nt->seq; *seq; seq++) {
|
||||
if (seq != nt->seq) {
|
||||
fprintf(file, " + ");
|
||||
}
|
||||
uint32_t count=1, length=0;
|
||||
readsequence(file, &count, &length, g, *seq);
|
||||
if(count == 1) {
|
||||
if(length == 1) {
|
||||
fprintf(file, "*t");
|
||||
}
|
||||
if(length > 1) {
|
||||
fprintf(file, "*t^%d", length);
|
||||
}
|
||||
} else if(count > 1) {
|
||||
if(length == 0) {
|
||||
fprintf(file, "*%d", count);
|
||||
}
|
||||
if(length == 1) {
|
||||
fprintf(file, "*%d*t", count);
|
||||
}
|
||||
if (length > 1) {
|
||||
fprintf(file, "*%d*t^%d", count, length);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fprintf(file, "\n");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
HParser* cfExample() {
|
||||
HParser *n = h_ch('n');
|
||||
HParser *E = h_indirect();
|
||||
HParser *T = h_choice(h_sequence(h_ch('('), E, h_ch(')'), NULL), n, NULL);
|
||||
HParser *E_ = h_choice(h_sequence(E, h_ch('-'), T, NULL), T, NULL);
|
||||
h_bind_indirect(E, E_);
|
||||
return E;
|
||||
}
|
||||
|
||||
// The tie knot parsers below would work better if we could patch the gen.function
|
||||
// code above to allow user specification of non-default byte string "lengths",
|
||||
// so that U symbols don't contribute with factors of t to the gen. function.
|
||||
//
|
||||
// Alternatively: use multivariate generating functions to spit out different
|
||||
// variables for different terminals. This gets really messy with bigger alphabets.
|
||||
|
||||
HParser* finkmao() {
|
||||
HParser *L = h_ch('L');
|
||||
HParser *R = h_ch('R');
|
||||
HParser *C = h_ch('C');
|
||||
HParser *U = h_ch('U');
|
||||
HParser *Lnext = h_indirect();
|
||||
HParser *Rnext = h_indirect();
|
||||
HParser *Cnext = h_indirect();
|
||||
HParser *L_ = h_choice(h_sequence(R, Rnext, NULL),
|
||||
h_sequence(C, Cnext, NULL),
|
||||
h_sequence(R, C, U, NULL), NULL);
|
||||
HParser *R_ = h_choice(h_sequence(L, Lnext, NULL),
|
||||
h_sequence(C, Cnext, NULL),
|
||||
h_sequence(L, C, U, NULL), NULL);
|
||||
HParser *C_ = h_choice(h_sequence(R, Rnext, NULL),
|
||||
h_sequence(L, Lnext, NULL), NULL);
|
||||
h_bind_indirect(Lnext, L_);
|
||||
h_bind_indirect(Rnext, R_);
|
||||
h_bind_indirect(Cnext, C_);
|
||||
HParser *tie = h_choice(h_sequence(L, Lnext), NULL);
|
||||
return tie;
|
||||
}
|
||||
|
||||
HParser* finkmaoTW() {
|
||||
HParser *T = h_ch('T');
|
||||
HParser *W = h_ch('W');
|
||||
HParser *U = h_ch('U');
|
||||
HParser *prefix = h_choice(T, W, h_epsilon_p(), NULL);
|
||||
HParser *pair = h_repeat_n(h_choice(T, W, NULL), 2);
|
||||
HParser *tuck = h_choice(h_sequence(T, T, U, NULL),
|
||||
h_sequence(W, W, U, NULL),
|
||||
NULL);
|
||||
return h_choice(h_sequence(prefix, h_many(pair), tuck, NULL));
|
||||
}
|
||||
|
||||
HParser* depth1TW() {
|
||||
HParser *T = h_ch('T');
|
||||
HParser *W = h_ch('W');
|
||||
HParser *U = h_ch('U');
|
||||
HParser *prefix = h_choice(T, W, h_epsilon_p(), NULL);
|
||||
HParser *pair = h_repeat_n(h_choice(T, W, NULL), 2);
|
||||
HParser *tuck = h_choice(h_sequence(T, T, U, NULL),
|
||||
h_sequence(W, W, U, NULL),
|
||||
NULL);
|
||||
return h_choice(h_sequence(prefix, h_many(h_choice(pair, tuck)), tuck, NULL));
|
||||
}
|
||||
|
||||
HParser* depth1() {
|
||||
HParser *L = h_ch('L');
|
||||
HParser *R = h_ch('R');
|
||||
HParser *C = h_ch('C');
|
||||
HParser *U = h_ch('U');
|
||||
HParser *lastR = h_indirect();
|
||||
HParser *lastL = h_indirect();
|
||||
HParser *lastC = h_indirect();
|
||||
HParser *R_ = h_choice(h_sequence(L, R, lastR, NULL),
|
||||
h_sequence(C, R, lastR, NULL),
|
||||
h_sequence(L, C, lastC, NULL),
|
||||
h_sequence(L, C, U, lastC, NULL),
|
||||
h_sequence(L, C, U, NULL),
|
||||
h_sequence(C, L, lastL, NULL),
|
||||
h_sequence(C, L, U, lastL, NULL),
|
||||
h_sequence(C, L, U, NULL),
|
||||
NULL);
|
||||
HParser *L_ = h_choice(h_sequence(R, L, lastR, NULL),
|
||||
h_sequence(C, L, lastR, NULL),
|
||||
h_sequence(R, C, lastC, NULL),
|
||||
h_sequence(R, C, U, lastC, NULL),
|
||||
h_sequence(R, C, U, NULL),
|
||||
h_sequence(C, R, lastR, NULL),
|
||||
h_sequence(C, R, U, lastR, NULL),
|
||||
h_sequence(C, R, U, NULL),
|
||||
NULL);
|
||||
HParser *C_ = h_choice(h_sequence(L, C, lastR, NULL),
|
||||
h_sequence(R, C, lastR, NULL),
|
||||
h_sequence(L, R, lastR, NULL),
|
||||
h_sequence(L, R, U, lastR, NULL),
|
||||
h_sequence(L, R, U, NULL),
|
||||
h_sequence(R, L, lastL, NULL),
|
||||
h_sequence(R, L, U, lastL, NULL),
|
||||
h_sequence(R, L, U, NULL),
|
||||
NULL);
|
||||
h_bind_indirect(lastR, R_);
|
||||
h_bind_indirect(lastL, L_);
|
||||
h_bind_indirect(lastC, C_);
|
||||
return h_choice(h_sequence(L, lastL, NULL),
|
||||
h_sequence(R, lastR, NULL),
|
||||
h_sequence(C, lastC, NULL),
|
||||
NULL);
|
||||
}
|
||||
|
||||
HParser* depthNTW() {
|
||||
HParser *T = h_ch('T');
|
||||
HParser *W = h_ch('W');
|
||||
HParser *U = h_ch('U');
|
||||
HParser *prefix = h_choice(T, W, h_epsilon_p(), NULL);
|
||||
HParser *pair = h_repeat_n(h_choice(T, W, NULL), 2);
|
||||
HParser *tstart = h_indirect();
|
||||
HParser *tw0 = h_indirect();
|
||||
HParser *tw1 = h_indirect();
|
||||
HParser *tw2 = h_indirect();
|
||||
HParser *wstart = h_indirect();
|
||||
HParser *wt0 = h_indirect();
|
||||
HParser *wt1 = h_indirect();
|
||||
HParser *wt2 = h_indirect();
|
||||
|
||||
HParser *T_ = h_choice(h_sequence(T, T, tw2, U, NULL),
|
||||
h_sequence(T, W, tw0, U, NULL),
|
||||
NULL);
|
||||
HParser *tw0_ = h_choice(h_sequence(T, T, tw2, U, NULL),
|
||||
h_sequence(T, W, tw0, U, NULL),
|
||||
h_sequence(W, T, tw0, U, NULL),
|
||||
h_sequence(W, W, tw1, U, NULL),
|
||||
h_sequence(tstart, tw2, U, NULL),
|
||||
h_sequence(wstart, tw1, U, NULL),
|
||||
NULL);
|
||||
HParser *tw1_ = h_choice(h_sequence(T, T, tw0, U, NULL),
|
||||
h_sequence(T, W, tw1, U, NULL),
|
||||
h_sequence(W, T, tw1, U, NULL),
|
||||
h_sequence(W, W, tw2, U, NULL),
|
||||
h_sequence(tstart, tw0, U, NULL),
|
||||
h_sequence(wstart, tw2, U, NULL),
|
||||
NULL);
|
||||
HParser *tw2_ = h_choice(h_sequence(T, T, tw1, U, NULL),
|
||||
h_sequence(T, W, tw2, U, NULL),
|
||||
h_sequence(W, T, tw2, U, NULL),
|
||||
h_sequence(W, W, tw0, U, NULL),
|
||||
h_sequence(tstart, tw1, U, NULL),
|
||||
h_sequence(wstart, tw0, U, NULL),
|
||||
h_epsilon_p(),
|
||||
NULL);
|
||||
|
||||
HParser *W_ = h_choice(h_sequence(W, W, wt2, U, NULL),
|
||||
h_sequence(W, T, wt0, U, NULL),
|
||||
NULL);
|
||||
HParser *wt0_ = h_choice(h_sequence(W, W, wt2, U, NULL),
|
||||
h_sequence(W, T, wt0, U, NULL),
|
||||
h_sequence(T, W, wt0, U, NULL),
|
||||
h_sequence(T, T, wt1, U, NULL),
|
||||
h_sequence(wstart, wt2, U, NULL),
|
||||
h_sequence(tstart, wt1, U, NULL),
|
||||
NULL);
|
||||
HParser *wt1_ = h_choice(h_sequence(W, W, wt0, U, NULL),
|
||||
h_sequence(W, T, wt1, U, NULL),
|
||||
h_sequence(T, W, wt1, U, NULL),
|
||||
h_sequence(T, T, wt2, U, NULL),
|
||||
h_sequence(wstart, wt0, U, NULL),
|
||||
h_sequence(tstart, wt2, U, NULL),
|
||||
NULL);
|
||||
HParser *wt2_ = h_choice(h_sequence(W, W, wt1, U, NULL),
|
||||
h_sequence(W, T, wt2, U, NULL),
|
||||
h_sequence(T, W, wt2, U, NULL),
|
||||
h_sequence(T, T, wt0, U, NULL),
|
||||
h_sequence(wstart, wt1, U, NULL),
|
||||
h_sequence(tstart, wt0, U, NULL),
|
||||
h_epsilon_p(),
|
||||
NULL);
|
||||
|
||||
h_bind_indirect(tstart, T_);
|
||||
h_bind_indirect(tw0, tw0_);
|
||||
h_bind_indirect(tw1, tw1_);
|
||||
h_bind_indirect(tw2, tw2_);
|
||||
h_bind_indirect(wstart, W_);
|
||||
h_bind_indirect(wt0, wt0_);
|
||||
h_bind_indirect(wt1, wt1_);
|
||||
h_bind_indirect(wt2, wt2_);
|
||||
|
||||
HParser *tuck = h_choice(tstart, wstart, NULL);
|
||||
return h_choice(h_sequence(prefix, h_many(h_choice(pair, tuck)), tuck, NULL));
|
||||
}
|
||||
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
HAllocator *mm__ = &system_allocator;
|
||||
|
||||
|
||||
HCFGrammar *g = h_cfgrammar_(mm__, h_desugar_augmented(mm__, cfExample()));
|
||||
if (g == NULL) {
|
||||
fprintf(stderr, "h_cfgrammar failed\n");
|
||||
return 1;
|
||||
}
|
||||
printf("\n==== Generating functions ====\n");
|
||||
h_pprint_gfeqns(stdout, g);
|
||||
|
||||
printf("\n==== Grammar ====\n");
|
||||
h_pprint_grammar(stdout, g, 0);
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue