common: add generic input-line interface, and an implementation of it for text files

common/file.c

@@ -0,0 +1,42 @@
+#include <ivy/file.h>
+#include <stdlib.h>
+#include <string.h>
+
+static enum ivy_status file_readline(
+	struct ivy_line_source *src, char *buf, size_t count, size_t *nr_read,
+	const char *prompt)
+{
+	if (!count) {
+		*nr_read = 0;
+		return IVY_OK;
+	}
+
+	struct ivy_file *f = (struct ivy_file *)src;
+	if (!fgets(buf, count, f->f_fp)) {
+		return feof(f->f_fp) ? IVY_ERR_EOF : IVY_ERR_IO_FAILURE;
+	}
+
+	*nr_read = strlen(buf);
+	return IVY_OK;
+}
+
+struct ivy_file *ivy_file_from_fp(FILE *fp)
+{
+	struct ivy_file *file = malloc(sizeof *file);
+	if (!file) {
+		return NULL;
+	}
+
+	memset(file, 0x0, sizeof *file);
+
+	file->f_fp = fp;
+	file->f_base.s_readline = file_readline;
+
+	return file;
+}
+
+void ivy_file_close(struct ivy_file *file)
+{
+	fclose(file->f_fp);
+	free(file);
+}

common/include/ivy/file.h

@@ -0,0 +1,15 @@
+#ifndef IVY_COMMON_FILE_H_
+#define IVY_COMMON_FILE_H_
+
+#include <ivy/line-source.h>
+#include <stdio.h>
+
+struct ivy_file {
+	struct ivy_line_source f_base;
+	FILE *f_fp;
+};
+
+extern struct ivy_file *ivy_file_from_fp(FILE *fp);
+extern void ivy_file_close(struct ivy_file *file);
+
+#endif

common/include/ivy/line-source.h

@@ -1,21 +1,15 @@
 #ifndef IVY_COMMON_LINE_SOURCE_H_
 #define IVY_COMMON_LINE_SOURCE_H_
 
+#include <ivy/status.h>
 #include <stddef.h>
 
-enum ivy_line_source_status {
-	IVY_LS_OK = 0,
-	IVY_LS_EOF,
-	IVY_LS_ERR_IOERR,
-	IVY_LS_ERR_NOSYS,
-};
-
 struct ivy_line_source {
-	enum ivy_line_source_status (*s_readline)(
+	enum ivy_status (*s_readline)(
 		struct ivy_line_source *, char *, size_t, size_t *, const char *);
 };
 
-extern enum ivy_line_source_status ivy_line_source_readline(
+extern enum ivy_status ivy_line_source_readline(
 	struct ivy_line_source *src, char *buf, size_t count, size_t *nr_read,
 	const char *prompt);
 

common/include/ivy/status.h

@@ -0,0 +1,15 @@
+#ifndef IVY_COMMON_STATUS_H_
+#define IVY_COMMON_STATUS_H_
+
+enum ivy_status {
+	IVY_OK = 0,
+	IVY_ERR_EOF = -1,
+	IVY_ERR_IO_FAILURE = -2,
+	IVY_ERR_BAD_SYNTAX = -3,
+	IVY_ERR_NO_MEMORY = -4,
+	IVY_ERR_NOT_SUPPORTED = -5,
+};
+
+extern const char *ivy_status_to_string(enum ivy_status status);
+
+#endif

common/line-source.c

@@ -1,6 +1,6 @@
 #include <ivy/line-source.h>
 
-enum ivy_line_source_status ivy_line_source_readline(
+enum ivy_status ivy_line_source_readline(
 	struct ivy_line_source *src, char *buf, size_t count, size_t *nr_read,
 	const char *prompt)
 {
@@ -8,5 +8,5 @@ enum ivy_line_source_status ivy_line_source_readline(
 		return src->s_readline(src, buf, count, nr_read, prompt);
 	}
 
-	return IVY_LS_ERR_NOSYS;
+	return IVY_ERR_NOT_SUPPORTED;
 }

common/status.c

@@ -0,0 +1,19 @@
+#include <ivy/status.h>
+
+#define ENUM_STR(x)                                                            \
+	case x:                                                                \
+		return #x
+
+const char *ivy_status_to_string(enum ivy_status status)
+{
+	switch (status) {
+		ENUM_STR(IVY_OK);
+		ENUM_STR(IVY_ERR_EOF);
+		ENUM_STR(IVY_ERR_IO_FAILURE);
+		ENUM_STR(IVY_ERR_BAD_SYNTAX);
+		ENUM_STR(IVY_ERR_NO_MEMORY);
+		ENUM_STR(IVY_ERR_NOT_SUPPORTED);
+	default:
+		return "";
+	}
+}