First backend! Text output now pretty much works.

[originally from svn r240]

1 files changed, 444 insertions, 0 deletions

diff --git a/bk_text.c b/bk_text.c
new file mode 100644
index 0000000..786c126
--- /dev/null
+++ b/bk_text.c
@@ -0,0 +1,444 @@
+/*
+ * text backend for Buttress
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "buttress.h"
+
+typedef enum { LEFT, CENTRE } alignment;
+
+typedef struct {
+    int indent;
+    int listindentbefore, listindentafter;
+    int width;
+    alignment titlealign, chapteralign;
+    wchar_t titleunderline, chapterunderline;
+    int include_version_id;
+    int indent_preambles;
+    word bullet;
+} textconfig;
+
+static int text_convert(wchar_t *, char **);
+
+static void text_title(FILE *, word *, word *, alignment, wchar_t, int, int);
+static void text_heading(FILE *, word *, word *, int, int);
+static void text_para(FILE *, word *, char *, word *, int, int, int);
+static void text_codepara(FILE *, word *, int, int);
+static void text_versionid(FILE *, word *);
+
+static textconfig text_configure(paragraph *sourceform) {
+    textconfig ret;
+
+    /*
+     * Non-negotiables.
+     */
+    ret.bullet.next = NULL;
+    ret.bullet.alt = NULL;
+    ret.bullet.type = word_Normal;
+
+    /*
+     * Defaults.
+     */
+    ret.indent = 7;
+    ret.listindentbefore = 1;
+    ret.listindentafter = 3;
+    ret.width = 68;
+    ret.titlealign = CENTRE;
+    ret.titleunderline = L'=';
+    ret.chapteralign = LEFT;
+    ret.chapterunderline = L'-';
+    ret.include_version_id = TRUE;
+    ret.indent_preambles = FALSE;
+    ret.bullet.text = ustrdup(L"-");
+
+    /*
+     * FIXME: must walk the source form gleaning configuration from
+     * \config paragraphs.
+     */
+    IGNORE(sourceform);		       /* for now */
+
+    return ret;
+}
+
+void text_backend(paragraph *sourceform, keywordlist *keywords, index *idx) {
+    paragraph *p;
+    textconfig conf;
+    word *prefix, *body, *wp;
+    word spaceword;
+    FILE *fp;
+    char *prefixextra;
+    int indentb, indenta;
+
+    IGNORE(keywords);		       /* we don't happen to need this */
+    IGNORE(idx);		       /* or this */
+
+    conf = text_configure(sourceform);
+
+    /*
+     * Determine the output file name, and open the output file
+     *
+     * FIXME: want configurable output file names here. For the
+     * moment, we'll just call it `output.txt'.
+     */
+    fp = fopen("output.txt", "w");
+    if (!fp) {
+	error(err_cantopenw, "output.txt");
+	return;
+    }
+
+    /* Do the title */
+    for (p = sourceform; p; p = p->next)
+	if (p->type == para_Title)
+	    text_title(fp, NULL, p->words,
+		       conf.titlealign, conf.titleunderline,
+		       conf.indent, conf.width);
+
+    /* Do the preamble and copyright */
+    for (p = sourceform; p; p = p->next)
+	if (p->type == para_Preamble)
+	    text_para(fp, NULL, NULL, p->words,
+		      conf.indent_preambles ? conf.indent : 0, 0,
+		      conf.width + (conf.indent_preambles ? 0 : conf.indent));
+    for (p = sourceform; p; p = p->next)
+	if (p->type == para_Copyright)
+	    text_para(fp, NULL, NULL, p->words,
+		      conf.indent_preambles ? conf.indent : 0, 0,
+		      conf.width + (conf.indent_preambles ? 0 : conf.indent));
+
+    /* Do the main document */
+    for (p = sourceform; p; p = p->next) switch (p->type) {
+
+	/*
+	 * Things we ignore because we've already processed them or
+	 * aren't going to touch them in this pass.
+	 */
+      case para_IM:
+      case para_BR:
+      case para_Biblio:		       /* only touch BiblioCited */
+      case para_VersionID:
+      case para_Copyright:
+      case para_Preamble:
+      case para_NoCite:
+      case para_Title:
+	break;
+
+	/*
+	 * Chapter titles.
+	 */
+      case para_Chapter:
+      case para_Appendix:
+      case para_UnnumberedChapter:
+	text_title(fp, p->kwtext, p->words,
+		   conf.chapteralign, conf.chapterunderline,
+		   conf.indent, conf.width);
+	break;
+
+      case para_Heading:
+      case para_Subsect:
+	text_heading(fp, p->kwtext2, p->words, conf.indent, conf.width);
+	break;
+
+      case para_Normal:
+      case para_BiblioCited:	       /* FIXME: put the citation on front */
+      case para_Bullet:
+      case para_NumberedList:
+	if (p->type == para_Bullet) {
+	    prefix = &conf.bullet;
+	    prefixextra = NULL;
+	    indentb = conf.listindentbefore;
+	    indenta = conf.listindentafter;
+	} else if (p->type == para_NumberedList) {
+	    prefix = p->kwtext;
+	    prefixextra = ".";
+	    indentb = conf.listindentbefore;
+	    indenta = conf.listindentafter;
+	} else {
+	    prefix = NULL;
+	    prefixextra = NULL;
+	    indentb = indenta = 0;
+	}
+	if (p->type == para_BiblioCited) {
+	    body = dup_word_list(p->kwtext);
+	    for (wp = body; wp->next; wp = wp->next);
+	    wp->next = &spaceword;
+	    spaceword.next = p->words;
+	    spaceword.alt = NULL;
+	    spaceword.type = word_WhiteSpace;
+	    spaceword.text = NULL;
+	} else {
+	    wp = NULL;
+	    body = p->words;
+	}
+	text_para(fp, prefix, prefixextra, body,
+		  conf.indent + indentb, indenta, conf.width);
+	if (wp) {
+	    wp->next = NULL;
+	    free_word_list(body);
+	}
+	break;
+
+      case para_Code:
+	text_codepara(fp, p->words, conf.indent, conf.width);
+	break;
+    }
+
+    /* Do the version ID */
+    if (conf.include_version_id) {
+	for (p = sourceform; p; p = p->next)
+	    if (p->type == para_VersionID)
+ 		text_versionid(fp, p->words);
+    }
+
+    /*
+     * Tidy up
+     */
+    fclose(fp);
+    sfree(conf.bullet.text);
+}
+
+/*
+ * Convert a wide string into a string of chars. If `result' is
+ * non-NULL, mallocs the resulting string and stores a pointer to
+ * it in `*result'. If `result' is NULL, merely checks whether all
+ * characters in the string are feasible for the output character
+ * set.
+ *
+ * Return is nonzero if all characters are OK. If not all
+ * characters are OK but `result' is non-NULL, a result _will_
+ * still be generated!
+ */
+static int text_convert(wchar_t *s, char **result) {
+    /*
+     * FIXME. Currently this is ISO8859-1 only.
+     */
+    int doing = (result != 0);
+    int ok = TRUE;
+    char *p = NULL;
+    int plen = 0, psize = 0;
+
+    for (; *s; s++) {
+	wchar_t c = *s;
+	char outc;
+
+	if ((c >= 32 && c <= 126) ||
+	    (c >= 160 && c <= 255)) {
+	    /* Char is OK. */
+	    outc = (char)c;
+	} else {
+	    /* Char is not OK. */
+	    ok = FALSE;
+	    outc = 0xBF;	       /* approximate the good old DEC `uh?' */
+	}
+	if (doing) {
+	    if (plen >= psize) {
+		psize = plen + 256;
+		p = resize(p, psize);
+	    }
+	    p[plen++] = outc;
+	}
+    }
+    if (doing) {
+	p = resize(p, plen+1);
+	p[plen] = '\0';
+	*result = p;
+    }
+    return ok;
+}
+
+static void text_rdaddwc(rdstringc *rs, word *text, word *end) {
+    char *c;
+
+    for (; text && text != end; text = text->next) switch (text->type) {
+      case word_HyperLink:
+      case word_HyperEnd:
+      case word_UpperXref:
+      case word_LowerXref:
+      case word_XrefEnd:
+      case word_IndexRef:
+	break;
+
+      case word_Normal:
+      case word_Emph:
+      case word_Code:
+      case word_WeakCode:
+	if (text->type == word_Emph)
+	    rdaddc(rs, '_');	       /* FIXME: configurability */
+	else if (text->type == word_Code)
+	    rdaddc(rs, '`');	       /* FIXME: configurability */
+	if (text_convert(text->text, &c))
+	    rdaddsc(rs, c);
+	else
+	    text_rdaddwc(rs, text->alt, NULL);
+	sfree(c);
+	if (text->type == word_Emph)
+	    rdaddc(rs, '_');	       /* FIXME: configurability */
+	else if (text->type == word_Code)
+	    rdaddc(rs, '\'');	       /* FIXME: configurability */
+	break;
+
+      case word_WhiteSpace:
+	rdaddc(rs, ' ');
+	break;
+    }
+}
+
+static int text_width(word *);
+
+static int text_width_list(word *text) {
+    int w = 0;
+    while (text) {
+	w += text_width(text);
+	text = text->next;
+    }
+    return w;
+}
+
+static int text_width(word *text) {
+    switch (text->type) {
+      case word_HyperLink:
+      case word_HyperEnd:
+      case word_UpperXref:
+      case word_LowerXref:
+      case word_XrefEnd:
+      case word_IndexRef:
+	return 0;
+
+      case word_Normal:
+      case word_Emph:
+      case word_Code:
+      case word_WeakCode:
+	return ((text->type == word_Emph || text->type == word_Code ? 2 : 0) +
+		(text_convert(text->text, NULL) ?
+		 ustrlen(text->text) :
+		 text_width_list(text->alt)));
+
+      case word_WhiteSpace:
+	return 1;
+    }
+    return 0;			       /* should never happen */
+}
+
+static void text_title(FILE *fp, word *prefix, word *text,
+		       alignment align, wchar_t underline,
+		       int indent, int width) {
+    rdstringc t = { 0, 0, NULL };
+    int margin, length;
+
+    if (prefix) {
+	text_rdaddwc(&t, prefix, NULL);
+	rdaddsc(&t, ": ");
+    }
+    text_rdaddwc(&t, text, NULL);
+
+    length = strlen(t.text);
+    if (align == CENTRE) {
+	margin = (indent + width - length)/2;
+	if (margin < 0) margin = 0;
+    } else
+	margin = 0;
+
+    fprintf(fp, "%*s%s\n", margin, "", t.text);
+    if (underline != L'\0') {
+	char *u, uc;
+	wchar_t uw[2];
+	uw[0] = underline; uw[1] = L'\0';
+	text_convert(uw, &u);
+	uc = u[0];
+	sfree(u);
+	fprintf(fp, "%*s", margin, "");
+	while (length--)
+	    putc(uc, fp);
+	putc('\n', fp);
+    }
+    putc('\n', fp);
+
+    sfree(t.text);
+}
+
+static void text_heading(FILE *fp, word *prefix, word *text,
+			 int indent, int width) {
+    rdstringc t = { 0, 0, NULL };
+    int margin;
+
+    if (prefix) {
+	text_rdaddwc(&t, prefix, NULL);
+	rdaddc(&t, ' ');
+	margin = strlen(t.text);
+    }
+    text_rdaddwc(&t, text, NULL);
+
+    margin = indent - margin;
+    if (margin < 0) margin = 0;
+
+    fprintf(fp, "%*s%s\n\n", margin, "", t.text);
+
+    if (strlen(t.text) > (size_t)width) {
+	/* FIXME: warn */
+    }
+
+    sfree(t.text);
+}
+
+static void text_para(FILE *fp, word *prefix, char *prefixextra, word *text,
+		      int indent, int extraindent, int width) {
+    wrappedline *wrapping, *p;
+    rdstringc pfx = { 0, 0, NULL };
+    int e;
+    int firstlinewidth = width;
+
+    if (prefix) {
+	text_rdaddwc(&pfx, prefix, NULL);
+	if (prefixextra)
+	    rdaddsc(&pfx, prefixextra);
+	fprintf(fp, "%*s%s", indent, "", pfx.text);
+	e = extraindent - strlen(pfx.text);
+	if (e < 0) {
+	    e = 0;
+	    firstlinewidth -= e;
+	    if (firstlinewidth < 0) {
+		e = indent + extraindent;
+		firstlinewidth = width;
+		fprintf(fp, "\n");
+	    }
+	}
+	sfree(pfx.text);
+    } else
+	e = indent + extraindent;
+
+    wrapping = wrap_para(text, firstlinewidth, width, text_width);
+    for (p = wrapping; p; p = p->next) {
+	rdstringc t = { 0, 0, NULL };
+	text_rdaddwc(&t, p->begin, p->end);
+	fprintf(fp, "%*s%s\n", e, "", t.text);
+	e = indent + extraindent;
+	sfree(t.text);
+    }
+    wrap_free(wrapping);
+    putc('\n', fp);
+}
+
+static void text_codepara(FILE *fp, word *text, int indent, int width) {
+    for (; text; text = text->next) if (text->type == word_WeakCode) {
+	char *c;
+	text_convert(text->text, &c);
+	if (strlen(c) > (size_t)width) {
+	    /* FIXME: warn */
+	}
+	fprintf(fp, "%*s%s\n", indent, "", c);
+	sfree(c);
+    }
+
+    putc('\n', fp);
+}
+
+static void text_versionid(FILE *fp, word *text) {
+    rdstringc t = { 0, 0, NULL };
+
+    rdaddc(&t, '[');		       /* FIXME: configurability */
+    text_rdaddwc(&t, text, NULL);
+    rdaddc(&t, ']');		       /* FIXME: configurability */
+
+    fprintf(fp, "%s\n\n", t.text);
+    sfree(t.text);
+}