Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[dev] mobile: add Help function that returns the contents for 'help' #10

Merged
merged 2 commits into from
Aug 27, 2015
Merged

[dev] mobile: add Help function that returns the contents for 'help' #10

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
213b493
[dev] mobile: add Help function that returns the contents for 'help' …
hyangah Aug 25, 2015
27de525
mobile: combine gofmt into help_gen.go.
hyangah Aug 26, 2015
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
332 changes: 332 additions & 0 deletions mobile/help.go
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,332 @@
package mobile

// GENERATED; DO NOT EDIT
const help = `<!-- auto-generated from robpike.io/ivy package doc -->

<head>
<style>
body {
font-family: Arial, sans-serif;
font-size: 10pt;
line-height: 1.3em;
max-width: 950px;
word-break: normal;
word-wrap: normal;
}

pre {
border-radius: 10px;
border: 2px solid #8AC007;
font-family: monospace;
font-size: 10pt;
overflow: auto;
padding: 10px;
white-space: pre;
}
</style>
</head>
<body>
<p>
Ivy is an interpreter for an APL-like language. It is a plaything and a work in
progress.
</p>
<p>
Unlike APL, the input is ASCII and the results are exact (but see the next paragraph).
It uses exact rational arithmetic so it can handle arbitrary precision. Values to be
input may be integers (3, -1), rationals (1/3, -45/67) or floating point values (1e3,
-1.5 (representing 1000 and -3/2)).
</p>
<p>
Some functions such as sqrt are irrational. When ivy evaluates an irrational
function, the result is stored in a high-precision floating-point number (default
256 bits of mantissa). Thus when using irrational functions, the values have high
precision but are not exact.
</p>
<p>
Unlike in most other languages, operators always have the same precedence and
expressions are evaluated in right-associative order. That is, unary operators
apply to everything to the right, and binary operators apply to the operand
immediately to the left and to everything to the right. Thus, 3*4+5 is 27 (it
groups as 3*(4+5)) and iota 3+2 is 1 2 3 4 5 while 3+iota 2 is 3 4 5. A vector
is a single operand, so 1 2 3 + 3 + 3 4 5 is (1 2 3) + 3 + (3 4 5), or 7 9 11.
</p>
<p>
Only a subset of APL&#39;s functionality is implemented, but the intention is to
have most numerical operations supported eventually.
</p>
<p>
Semicolons separate multiple statements on a line. Variables are alphanumeric and are
assigned with the = operator.
</p>
<p>
The APL operators, adapted from <a href="https://en.wikipedia.org/wiki/APL_syntax_and_symbols">https://en.wikipedia.org/wiki/APL_syntax_and_symbols</a>,
and their correspondence are listed here. The correspondence is incomplete and inexact.
</p>
<p>
Unary functions.
</p>
<pre>Name APL Ivy Meaning
Roll ?B ? One integer selected randomly from the first B integers
Ceiling ⌈B ceil Least integer greater than or equal to B
Floor ⌊B floor Greatest integer less than or equal to B
Shape ⍴B rho Number of components in each dimension of B
Not ∼B not Logical: not 1 is 0, not 0 is 1
Absolute value ∣B abs Magnitude of B
Index generator ⍳B iota Vector of the first B integers
Exponential ⋆B ** e to the B power
Negation −B - Changes sign of B
Identity +B + No change to B
Signum ×B sgn ¯1 if B&lt;0; 0 if B=0; 1 if B&gt;0
Reciprocal ÷B / 1 divided by B
Ravel ,B , Reshapes B into a vector
Matrix inverse ⌹B Inverse of matrix B
Pi times ○B Multiply by π
Logarithm ⍟B log Natural logarithm of B
Reversal ⌽B rev Reverse elements of B along last axis
Reversal ⊖B flip Reverse elements of B along first axis
Grade up ⍋B up Indices of B which will arrange B in ascending order
Grade down ⍒B down Indices of B which will arrange B in descending order
Execute ⍎B ivy Execute an APL (ivy) expression
Monadic format ⍕B text A character representation of B
Monadic transpose ⍉B Reverse the axes of B
Factorial !B Product of integers 1 to B
Bitwise not ^ Bitwise complement of B (integer only)
Square root B⋆.5 sqrt Square root of B.
Sine sin sin(A); APL uses binary ○ (see below)
Cosine cos cos(A); ditto
Tangent tan tan(A); ditto
</pre>
<p>
Binary functions.
</p>
<pre>Name APL Ivy Meaning
Add A+B + Sum of A and B
Subtract A−B - A minus B
Multiply A×B * A multiplied by B
Divide A÷B / A divided by B (exact rational division)
div A divided by B (Euclidean)
idiv A divided by B (Go)
Exponentiation A⋆B ** A raised to the B power
Circle A○B Trigonometric functions of B selected by A
A=1: sin(B) A=2: cos(B) A=3: tan(B); ¯A for inverse
sin sin(B); ivy uses traditional name.
cos cos(B); ivy uses traditional name.
tan tan(B); ivy uses traditional name.
asin arcsin(B); ivy uses traditional name.
acos arccos(B); ivy uses traditional name.
atan arctan(B); ivy uses traditional name.
Deal A?B A distinct integers selected randomly from the first B integers
Membership A∈B in 1 for elements of A present in B; 0 where not.
Maximum A⌈B max The greater value of A or B
Minimum A⌊B min The smaller value of A or B
Reshape A⍴B rho Array of shape A with data B
Take A↑B take Select the first (or last) A elements of B according to ×A
Drop A↓B drop Remove the first (or last) A elements of B according to ×A
Decode A⊥B decode Value of a polynomial whose coefficients are B at A
Encode A⊤B encode Base-A representation of the value of B
Residue A∣B B modulo A
mod A modulo B (Euclidean)
imod A modulo B (Go)
Catenation A,B , Elements of B appended to the elements of A
Expansion A\B fill Insert zeros (or blanks) in B corresponding to zeros in A
In ivy: abs(A) gives count, A &lt;= 0 inserts zero (or blank)
Compression A/B sel Select elements in B corresponding to ones in A
In ivy: abs(A) gives count, A &lt;= 0 inserts zero
Index of A⍳B iota The location (index) of B in A; 1+⌈/⍳⍴A if not found
In ivy: origin-1 if not found (i.e. 0 if one-indexed)
Matrix divide A⌹B Solution to system of linear equations Ax = B
Rotation A⌽B rot The elements of B are rotated A positions left
Rotation A⊖B The elements of B are rotated A positions along the first axis
Logarithm A⍟B log Logarithm of B to base A
Dyadic format A⍕B Format B into a character matrix according to A
General transpose A⍉B The axes of B are ordered by A
Combinations A!B Number of combinations of B taken A at a time
Less than A&lt;B &lt; Comparison: 1 if true, 0 if false
Less than or equal A≤B &lt;= Comparison: 1 if true, 0 if false
Equal A=B == Comparison: 1 if true, 0 if false
Greater than or equal A≥B &gt;= Comparison: 1 if true, 0 if false
Greater than A&gt;B &gt; Comparison: 1 if true, 0 if false
Not equal A≠B != Comparison: 1 if true, 0 if false
Or A∨B or Logic: 0 if A and B are 0; 1 otherwise
And A∧B and Logic: 1 if A and B are 1; 0 otherwise
Nor A⍱B nor Logic: 1 if both A and B are 0; otherwise 0
Nand A⍲B nand Logic: 0 if both A and B are 1; otherwise 1
Xor xor Logic: 1 if A != B; otherwise 0
Bitwise and &amp; Bitwise A and B (integer only)
Bitwise or | Bitwise A or B (integer only)
Bitwise xor ^ Bitwise A exclusive or B (integer only)
Left shift &lt;&lt; A shifted left B bits (integer only)
Right Shift &gt;&gt; A shifted right B bits (integer only)
</pre>
<p>
Operators and axis indicator
</p>
<pre> Name APL Ivy APL Example Ivy Example Meaning (of example)
Reduce (last axis) / / +/B +/B Sum across B
Reduce (first axis) ⌿ +⌿B Sum down B
Scan (last axis) \ \ +\B +\B Running sum across B
Scan (first axis) ⍀ +⍀B Running sum down B
Inner product . . A+.×B A +.* B Matrix product of A and B
Outer product ∘. o. A∘.×B A o.* B Outer product of A and B
(lower case o; may need preceding space)
</pre>
<p>
Type-converting operations
</p>
<pre>Name Ivy Meaning
Code code B The integer Unicode value of char B
Char char B The character with integer Unicode value B
Float float B The floating-point representation of B
Text text B The textual (vector of Char) representation of B
Evaluate ivy B The result of evaluating B as ivy program text
</pre>
<h3 id="hdr-Pre_defined_constants">Pre-defined constants</h3>
<p>
The constants e (base of natural logarithms) and pi (π) are pre-defined to high
precision, about 3000 decimal digits truncated according to the floating point
precision setting.
</p>
<h3 id="hdr-Character_data">Character data</h3>
<p>
Strings are vectors of &#34;chars&#34;, which are Unicode code points (not bytes).
Syntactically, string literals are very similar to those in Go, with back-quoted
raw strings and double-quoted interpreted strings. Unlike Go, single-quoted strings
are equivalent to double-quoted, a nod to APL syntax. A string with a single char
is just a singleton char value; all others are vectors. Thus &ldquo;, &#34;&#34;, and &rdquo; are
empty vectors, ` + "`" + `a` + "`" + `, &#34;a&#34;, and &#39;a&#39; are equivalent representations of a single char,
and ` + "`" + `ab` + "`" + `, ` + "`" + `a` + "`" + ` ` + "`" + `b` + "`" + `, &#34;ab&#34;, &#34;a&#34; &#34;b&#34;, &#39;ab&#39;, and &#39;a&#39; &#39;b&#39; are equivalent representations
of a two-char vector.
</p>
<p>
Unlike in Go, a string in ivy comprises code points, not bytes; as such it can
contain only valid Unicode values. Thus in ivy &#34;\x80&#34; is illegal, although it is
a legal one-byte string in Go.
</p>
<p>
Strings can be printed. If a vector contains only chars, it is printed without
spaces between them.
</p>
<p>
Chars have restricted operations. Printing, comparison, indexing and so on are
legal but arithmetic is not, and chars cannot be converted automatically into other
singleton values (ints, floats, and so on). The unary operators char and code
enable transcoding between integer and char values.
</p>
<h3 id="hdr-User_defined_operators">User-defined operators</h3>
<p>
Users can define unary and binary operators, which then behave just like
built-in operators. Both a unary and a binary operator may be defined for the
same name.
</p>
<p>
The syntax of a definition is the &#39;op&#39; keyword, the operator and formal
arguments, an equals sign, and then the body. The names of the operator and its
arguments must be identifiers. For unary operators, write &#34;op name arg&#34;; for
binary write &#34;op leftarg name rightarg&#34;. The final expression in the body is the
return value. Operators may have recursive definitions, but since there are
no conditional or looping constructs (yet), such operators are problematic
when executed.
</p>
<p>
The body may be a single line (possibly containing semicolons) on the same line
as the &#39;op&#39;, or it can be multiple lines. For a multiline entry, there is a
newline after the &#39;=&#39; and the definition ends at the first blank line (ignoring
spaces).
</p>
<p>
Example: average of a vector (unary):
</p>
<pre>op avg x = (+/x)/rho x
avg iota 11
result: 6
</pre>
<p>
Example: n largest entries in a vector (binary):
</p>
<pre>op n largest x = n take x[down x]
3 largest 7 1 3 24 1 5 12 5 51
result: 51 24 12
</pre>
<p>
Example: multiline operator definition (binary):
</p>
<pre>op a sum b =
a = a+b
a

iota 3 sum 4
result: 1 2 3 4 5 6 7
</pre>
<p>
To declare an operator but not define it, omit the equals sign and what follows.
</p>
<pre>op foo x
op bar x = foo x
op foo x = -x
bar 3
result: -3
op foo x = /x
bar 3
result: 1/3
</pre>
<p>
Within a user-defined operator, identifiers are local to the invocation unless
they are undefined in the operator but defined globally, in which case they refer to
the global variable. A mechanism to declare locals may come later.
</p>
<h3 id="hdr-Special_commands">Special commands</h3>
<p>
Ivy accepts a number of special commands, introduced by a right paren
at the beginning of the line. Most report the current value if a new value
is not specified. For these commands, numbers are always base 10 and
must be non-negative.
</p>
<pre>) help
Print this list of special commands.
) base 0
Set the number base for input and output. The commands ibase and
obase control setting of the base for input and output alone,
respectively. Base 0 allows C-style input: decimal, with 037 being
octal and 0x10 being hexadecimal. If the base is greater than 10,
any identifier formed from valid numerals in the base system, such
as abe for base 16, is taken to be a number. TODO: To output
large integers and rationals, base must be one of 0 2 8 10 16.
) debug name 0|1
Toggle or set the named debugging flag. With no argument, lists
the settings.
) format &#34;&#34;
Set the format for printing values. If empty, the output is printed
using the output base. If non-empty, the format determines the
base used in printing. The format is in the style of golang.org/pkg/fmt.
For floating-point formats, flags and width are ignored.
) get &#34;save.ivy&#34;
Read input from the named file; return to interactive execution
afterwards. If no file is specified, read from &#34;save.ivy&#34;.
) maxbits 1e6
To avoid consuming too much memory, if an integer result would
require more than this many bits to store, abort the calculation.
If maxbits is 0, there is no limit; the default is 1e6.
) maxdigits 1e4
To avoid overwhelming amounts of output, if an integer has more
than this many digits, print it using the defined floating-point
format. If maxdigits is 0, integers are always printed as integers.
) op X
Show the definition of the user-defined operator X. Inside the
definition, numbers are always shown base 10, ignoring the ibase
and obase.
) origin 1
Set the origin for indexing a vector or matrix.
) prec 256
Set the precision (mantissa length) for floating-point values.
The value is in bits. The exponent always has 32 bits.
) prompt &#34;&#34;
Set the interactive prompt.
) save &#34;save.ivy&#34;
Write definitions of user-defined operators and variables to the
named file, as ivy textual source. If no file is specified, save to
&#34;save.ivy&#34;.
) seed 0
Set the seed for the ? operator.
</pre>
</body></html>
`
Loading