gv(3sharp)

okay so this is gv(3sharp) and it’s literally the graph-manipulation manual, bestie 💅✨ buckle up because we’re about to make graphviz make sense.

🌸 NAME 🌸

gv_sharp — graph manipulation in sharp 🦋

⭐ SYNOPSIS ⭐

no synopsis lines here, bestie — it jumps straight into USAGE and INTRODUCTION ✨

🧚 USAGE 🧚

the original has no usage text here, just vibes 😭

💖 INTRODUCTION 💖

gv_sharp is a dynamically loaded extension for sharp that gives you access to the graph facilities of graphviz. no cap, that’s the whole intro and it ate 🫶

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🦋 COMMANDS 🦋

okay so this is the whole command menu. every signature is kept exactly as the original has it — no renames, no “fixing,” no funny business 🔥

✨ New graphs ✨

New empty graph

SWIGTYPE_p_Agraph_t gv.graph (string name);
SWIGTYPE_p_Agraph_t gv.digraph (string name);
SWIGTYPE_p_Agraph_t gv.strictgraph (string name);
SWIGTYPE_p_Agraph_t gv.strictdigraph (string name);

four ways to start a fresh empty graph, each one taking a name and handing you back a graph handle 👑

New graph from a dot-syntax string or file

SWIGTYPE_p_Agraph_t gv.readstring (string string);
SWIGTYPE_p_Agraph_t gv.read (string filename);
SWIGTYPE_p_Agraph_t gv.read (SWIGTYPE_p_FILE f);

readstring takes a dot-syntax string, and read takes either a filename or an open FILE handle. super straightforward, iconic behavior 🌟

Add new subgraph to existing graph

SWIGTYPE_p_Agraph_t gv.graph (SWIGTYPE_p_Agraph_t g, string name);

drops a new subgraph into an existing graph g, with the name you pass in 🎀

🌈 New nodes 🌈

Add new node to existing graph

SWIGTYPE_p_Agnode_t gv.node (SWIGTYPE_p_Agraph_t g, string name);

adds a new node to graph g and gives you the node handle back 💫

💫 New edges 💫

Add new edge between existing nodes

SWIGTYPE_p_Agedge_t gv.edge (SWIGTYPE_p_Agnode_t t, SWIGTYPE_p_Agnode_t h);

connects existing tail node t to existing head node h, and you get the edge handle 🫶

Add a new edge between an existing tail node, and a named head node which will be induced in the graph if it doesn’t already exist

SWIGTYPE_p_Agedge_t gv.edge (SWIGTYPE_p_Agnode_t t, string hname);

tail node is already there, and the named head node gets induced into the graph if it’s not already a thing ✨

Add a new edge between an existing head node, and a named tail node which will be induced in the graph if it doesn’t already exist

SWIGTYPE_p_Agedge_t gv.edge (string tname, SWIGTYPE_p_Agnode_t h);

same energy, but flipped: named tail gets induced if needed, and the head node already exists 💅

Add a new edge between named tail and head nodes which will be induced in the graph if they don’t already exist

SWIGTYPE_p_Agedge_t gv.edge (SWIGTYPE_p_Agraph_t g, string tname, string hname);

named tail and named head both get induced into graph g if they aren’t already there. main character edge energy for real 🌈

🎀 Setting attribute values 🎀

Set value of named attribute of graph/node/edge — creating attribute if necessary

string gv.setv (SWIGTYPE_p_Agraph_t g, string attr, string val);
string gv.setv (SWIGTYPE_p_Agnode_t n, string attr, string val);
string gv.setv (SWIGTYPE_p_Agedge_t e, string attr, string val);

sets the value of a named attribute on a graph, node, or edge, and creates the attribute if it has to. returns a string 🍓

Set value of existing attribute of graph/node/edge (using attribute handle)

string gv.setv (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agsym_t a, string val);
string gv.setv (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agsym_t a, string val);
string gv.setv (SWIGTYPE_p_Agedge_t e, SWIGTYPE_p_Agsym_t a, string val);

same setv era, but you’re passing an attribute handle a instead of a name. still returns a string 💖

🍓 Getting attribute values 🍓

Get value of named attribute of graph/node/edge

string gv.getv (SWIGTYPE_p_Agraph_t g, string attr);
string gv.getv (SWIGTYPE_p_Agnode_t n, string attr);
string gv.getv (SWIGTYPE_p_Agedge_t e, string attr);

grabs the value of a named attribute from a graph, node, or edge, and hands it back as a string ✨

Get value of attribute of graph/node/edge (using attribute handle)

string gv.getv (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agsym_t a);
string gv.getv (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agsym_t a);
string gv.getv (SWIGTYPE_p_Agedge_t e, SWIGTYPE_p_Agsym_t a);

same getv energy but with an attribute handle a instead of a name. returns a string 🎀

🫶 Obtain names from handles 🫶

string gv.nameof (SWIGTYPE_p_Agraph_t g);
string gv.nameof (SWIGTYPE_p_Agnode_t n);
string gv.nameof (SWIGTYPE_p_Agsym_t a);

you’ve got a handle, you want the name — gv.nameof says “say less” and returns a string 💅

🔍 Find handles from names 🔍

SWIGTYPE_p_Agraph_t gv.findsubg (SWIGTYPE_p_Agraph_t g, string name);
SWIGTYPE_p_Agnode_t gv.findnode (SWIGTYPE_p_Agraph_t g, string name);
SWIGTYPE_p_Agedge_t gv.findedge (SWIGTYPE_p_Agnode_t t, SWIGTYPE_p_Agnode_t h);
SWIGTYPE_p_Agsym_t gv.findattr (SWIGTYPE_p_Agraph_t g, string name);
SWIGTYPE_p_Agsym_t gv.findattr (SWIGTYPE_p_Agnode_t n, string name);
SWIGTYPE_p_Agsym_t gv.findattr (SWIGTYPE_p_Agedge_t e, string name);

the “I know the name, now give me the handle” corner. subgraphs, nodes, edges, and attributes all get their finder moment 🔥

🧭 Misc graph navigators returning handles 🧭

SWIGTYPE_p_Agnode_t gv.headof (SWIGTYPE_p_Agedge_t e);
SWIGTYPE_p_Agnode_t gv.tailof (SWIGTYPE_p_Agedge_t e);
SWIGTYPE_p_Agraph_t gv.graphof (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agraph_t gv.graphof (SWIGTYPE_p_Agedge_t e);
SWIGTYPE_p_Agraph_t gv.graphof (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agraph_t gv.rootof (SWIGTYPE_p_Agraph_t g);

little navigator besties that hand you back handles: head, tail, graph-of-this, graph-of-that, and root. iykyk 🌟

🧚 Obtain handles of proto node/edge for setting default attribute values 🧚

SWIGTYPE_p_Agnode_t gv.protonode (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agedge_t gv.protoedge (SWIGTYPE_p_Agraph_t g);

grab the proto node or proto edge handle for graph g when you’re setting default attribute values. very “set the vibe for everyone” of them 💜

🔁 Iterators 🔁

Iteration termination tests

bool gv.ok (SWIGTYPE_p_Agraph_t g);
bool gv.ok (SWIGTYPE_p_Agnode_t n);
bool gv.ok (SWIGTYPE_p_Agedge_t e);
bool gv.ok (SWIGTYPE_p_Agsym_t a);

the bool check that tells you whether your iteration handle is still okay. graph, node, edge, attribute — all covered ✅

Iterate over subgraphs of a graph

SWIGTYPE_p_Agraph_t gv.firstsubg (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agraph_t gv.nextsubg (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agraph_t sg);

first subgraph, then keep calling nextsubg with the current subgraph handle. classic iteration slay 🦋

Iterate over supergraphs of a graph (obscure and rarely useful)

SWIGTYPE_p_Agraph_t gv.firstsupg (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agraph_t gv.nextsupg (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agraph_t sg);

yes bestie, the original literally calls this obscure and rarely useful — so proceed with lowkey caution 😭

Iterate over edges of a graph

SWIGTYPE_p_Agedge_t gv.firstedge (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agedge_t gv.nextedge (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agedge_t e);

walks the edges of graph g, first one then next one until you’re done 🔥

Iterate over outedges of a graph

SWIGTYPE_p_Agedge_t gv.firstout (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agedge_t gv.nextout (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agedge_t e);

same idea but for outedges of a graph. outedge era 💫

Iterate over edges of a node

SWIGTYPE_p_Agedge_t gv.firstedge (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agedge_t gv.nextedge (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agedge_t e);

edge iteration, but scoped to node n 🎀

Iterate over out-edges of a node

SWIGTYPE_p_Agedge_t gv.firstout (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agedge_t gv.nextout (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agedge_t e);

out-edge iteration for a single node. no cap, it’s giving “follow the outgoing connections” 🌈

Iterate over head nodes reachable from out-edges of a node

SWIGTYPE_p_Agnode_t gv.firsthead (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agnode_t gv.nexthead (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agnode_t h);

walks the head nodes you can reach from node n’s out-edges. head node hunting, but make it cute 🫶

Iterate over in-edges of a graph

SWIGTYPE_p_Agedge_t gv.firstin (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agedge_t gv.nextin (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agedge_t e);

in-edge iteration for a graph. yes, the second signature is written exactly like that in the original — copy it as-is, bestie 😭

Iterate over in-edges of a node

SWIGTYPE_p_Agedge_t gv.firstin (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agedge_t gv.nextin (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agedge_t e);

in-edge iteration for a node. again, the second line is exactly the original signature — no edits from me 💅

Iterate over tail nodes reachable from in-edges of a node

SWIGTYPE_p_Agnode_t gv.firsttail (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agnode_t gv.nexttail (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agnode_t t);

tail node iteration from node n’s in-edges. tail besties, assemble 🌸

Iterate over nodes of a graph

SWIGTYPE_p_Agnode_t gv.firstnode (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agnode_t gv.nextnode (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agnode_t n);

walks every node in graph g. first node, next node, periodt 👑

Iterate over nodes of an edge

SWIGTYPE_p_Agnode_t gv.firstnode (SWIGTYPE_p_Agedge_t e);
SWIGTYPE_p_Agnode_t gv.nextnode (SWIGTYPE_p_Agedge_t e, SWIGTYPE_p_Agnode_t n);

node iteration scoped to edge e. yes, edges have nodes, and they’re getting iterated 💖

Iterate over attributes of a graph

SWIGTYPE_p_Agsym_t gv.firstattr (SWIGTYPE_p_Agraph_t g);
SWIGTYPE_p_Agsym_t gv.nextattr (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_Agsym_t a);

walks the attributes attached to graph g. attribute handle by attribute handle ✨

Iterate over attributes of an edge

SWIGTYPE_p_Agsym_t gv.firstattr (SWIGTYPE_p_Agedge_t e);
SWIGTYPE_p_Agsym_t gv.nextattr (SWIGTYPE_p_Agedge_t e, SWIGTYPE_p_Agsym_t a);

edge attribute iteration. every edge deserves its attribute moment 🎀

Iterate over attributes of a node

SWIGTYPE_p_Agsym_t gv.firstattr (SWIGTYPE_p_Agnode_t n);
SWIGTYPE_p_Agsym_t gv.nextattr (SWIGTYPE_p_Agnode_t n, SWIGTYPE_p_Agsym_t a);

node attribute iteration, same energy. iconic 🦋

💀 Remove graph objects 💀

bool gv.rm (SWIGTYPE_p_Agraph_t g);
bool gv.rm (SWIGTYPE_p_Agnode_t n);
bool gv.rm (SWIGTYPE_p_Agedge_t e);

removes a graph, node, or edge, and returns a bool. the “respectfully, delete it” corner 💅

📐 Layout 📐

Annotate a graph with layout attributes and values using a specific layout engine

bool gv.layout (SWIGTYPE_p_Agraph_t g, string engine);

runs layout on graph g with the engine you name, annotating it with layout attributes and values. returns a bool 🌟

🎨 Render 🎨

Render a layout into attributes of the graph

bool gv.render (SWIGTYPE_p_Agraph_t g);

renders a layout into the graph’s own attributes and returns a bool 🫶

Render a layout to stdout

bool gv.render (SWIGTYPE_p_Agraph_t g, string format);

renders to stdout in the format you pass. yes bestie, straight to stdout 💫

Render to an open file

bool gv.render (SWIGTYPE_p_Agraph_t g, string format, SWIGTYPE_p_FILE fout);

renders into the already-open file handle fout 🎀

Render a layout to an unopened file by name

bool gv.render (SWIGTYPE_p_Agraph_t g, string format, string filename);

gives you the filename version — it renders to a file by filename instead of an open handle 🌈

Render to a string result

string gv.renderresult (SWIGTYPE_p_Agraph_t ing, string format);
gv.renderresult (SWIGTYPE_p_Agraph_t g, string format, string outdata);

the first one returns a string; the second is written exactly like that in the original — no return type, don’t @ me 😭 keep it exact, bestie.

Render to an open channel

bool gv.renderchannel (SWIGTYPE_p_Agraph_t g, string format, string channelname);

renders to the open channel named by channelname, and returns a bool 🔥

Render a layout to a malloc’ed string, to be free’d by the caller

deprecated — too easy to leak memory 😭

still needed for "eval [gv::renderdata $G tk]" — yes, that exact quote is in the original.

string gv.renderdata (SWIGTYPE_p_Agraph_t g, string format);

returns a string that’s been malloc’ed and has to be free’d by the caller. deprecated because memory leaks are not the vibe, but still needed for that exact "eval [gv::renderdata $G tk]" situation 💀

💾 Writing graph back to file 💾

bool gv.write (SWIGTYPE_p_Agraph_t g, string filename);
bool gv.write (SWIGTYPE_p_Agraph_t g, SWIGTYPE_p_FILE f);

writes graph g back out — either by filename or to an open FILE handle f. returns a bool 🍓

🔧 Graph transformation tools 🔧

bool gv.tred (SWIGTYPE_p_Agraph_t g);

the transformation-tools corner: gv.tred on graph g, returning a bool 🛠️✨

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🌟 KEYWORDS 🌟

graph, dot, neato, fdp, circo, twopi, sharp. that’s the keyword lineup, no cap 💜

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and that’s the whole page, bestie 🫶 shoutout to the footer energy: source/version 1792256243 and manual gv(3sharp) — periodt 💅🎀